LORA Vin -> PI 3.3V
GND -> GND
G0 - > GPIO25
SCK - SCLK
MISO -> MISO
MOSI -> MOSI
CS - > CE0
RST -> GPIO17
#help-with-radio
normal drift
not a great pictire
hmm - I did see tat same error condition you reported one - may have been moving wires.
It lloks to me like the recieve is still intermittent. It may be sensitive to the wiring. I have pretty long wires - I'll try shorening them to see if that makes it better
reduced wires to ~ 12 cm - it is working - seems more stable
Shorter wires
so - my reccommendation is to make the wires as short as possible and make the connections as good as possible then don't touch it while it it running!
its been running here for the past 20 minutes
With that, I am going to declare victory. Next step for me is to make much better shorter connections to an RPI zerow and see if it performs better. I forgaot that I also have a >20cm ribbon cable from my "cobbler" to my Pi. SPI can be very sensitve to the signal quality. Long wires can result in erros and the error we each saw was due to a bad commication across the SPI interface. I have not sen any since I stopped moving things.
restive fjord
@normal drift can t cobbler make a difference? I dont have one. i am just connecting rpi straight to lora.
burnt kite
man. those RFM6x/9x chips are super level sensitive on the data lines... we keep running into that @normal drift.
normal drift
@restive fjord direct connection should be better.
@burnt kite they sure are!
I get much cleaner behavior with a feather M0 and a rfm95 featherwing.
restive fjord
@normal drift so i just figured out my wires are 18cm long. will cut it to 12cm tomorrow and let you know.
normal drift
@restive fjord It should work, but it may miss more packets. just make sure you have good connections.
shorter would be better
restive fjord
@normal drift okay. and what about G0 showing 5V on multimeter?
when it was transmitting i measured it
normal drift
makes no sense - are yu powering Vin from 3.3 V on the PI?
normal drift
makes no sense - I'll check min - may take a few minuts
restive fjord
okay. take ur time
normal drift
just looked on scope -- definately 3V
3.3V
a multimeter may not be accurate for a short signal like that
I can't measure it with a mutimeter. should not be 5V
so you cahnged the program to set GPIO 17 for the interrupt. Mine uses GPIO25
lora = rf95.RF95(0, 25, 17) is my setting -- G0 on GPIO 25, RST on GPIO17
are you sure you are not putting 5V into the Vin? double check.
the outputs will follow Vin - if you use 5V on Vin, then G0 and all signals will be 0-5V -- not good for RPi
restive fjord
@normal drift ok it works now. I literally moved nothing. All i did it I commented the #self.spi.open(0,self.cs) in the library
normal drift
@restive fjord interesting - what line # is that?
restive fjord
i commented all self.spi.open(0,self.cs) and self.spi.close() in the library
normal drift
ah -- good to know -- I'll look at that - I saw some discussion of that during one of my searches - glad it is working for you!
normal drift
@restive fjord would you please post your latest rf95.py? did you takeout all opens or leave the first one in place. I think you are helping me unravel a mystery!
normal drift
ah ha! I think my confusion regarding the the argument to the initialization of the interface and using ``` self.spi = spidev.SpiDev(0,0)
Thank you for discovering that the open/close were causing problems. This now makes a lot more sense to me. I'll do some more playing with it and post an updated version if I have anything to share.
normal drift
@restive fjord this has been interesting and I've leaned a few lessons. Here are new versions of the rf95.py and rh_new.py -- I removed "most" of the open/close calles but changed init a bit to use one call to open. This matches the spidev documentation much better and it allow you to use either cs=0 or cs=1 (pin CE0 or CE1). I then added a close to .cleanup. in rh_new.py it calls cleanup when a Control-C is entered from the keyboard - just being poilite! I also found that I get much better performance runnin ghtis in python3 python3 rh_new.py than if I run it in python2 python rh_new.py. they both work, but python2 missed alot more packets. Not sure why. So take a look at the modified code and let me know if you have any questions.
modified rf95.py with only one open/close
modified rh_new.py with control-c exception to call cleanup
restive fjord
@normal drift thank you I will test it and let you know.
normal drift
@restive fjord just an update -- see recent discussion on #circuitpython-dev (now) re spidev.. I don't think removing the open/close was the correct thing to do. I'll work on it and update as I can.
normal drift
restored open/close -- works here.
this version is very close to the original - added the LOW to the RESET and a minor tweak to the init use of open/close. Still not sure why I had to change that to get it to work.
restive fjord
@normal drift so I am testing rh_new.py with rf95 library which has commented stuffs in it. So far it has 1015 messages, and it it showing this error
File "/home/pi/programs/Tests/pyRF95_mine/rf95.py", line 434, in send
File "/home/pi/programs/Tests/pyRF95_mine/rf95.py", line 333, in spi_write_data
IOError: [Errno 24] Too many open files
oh it send a message every second
normal drift
Sorry. I’ll look into it later tonight. I may not have run it long enough. Looks like I missed a close somewhere.
normal drift
Oh. Try it if you have time.
restive fjord
ok
restive fjord
@normal drift wow. it works so well. its been runninng for 30min straight without any problem.
normal drift
@silver marten my pleasure -- glad to help and I learned a lot from this!
silver marten
I did too. I will have to see if I can break the world record tx distance on lora
normal drift
good luck -- how far is it?
normal drift
?? wow!
normal drift
amazing stuff -- I work on a project that uses GPS at 43,000miles https://www.nasa.gov/feature/goddard/2016/nasa-s-mms-breaks-guinness-world-record
I don't work on the spacecraft -- one of the science instruments.
silver marten
Oh
normal drift
still - the rf challenges and accomplishments for spacecraft are incredible,
silver marten
You can send vhf and higher freqs through weather. Like rain. The rain ducts at the GHz freqs and if the rain is in sight of both stations then you can communicate long distances
You can bounce it along the leading or trailing edge of fronts too
normal drift
interesting - I've heard about using fronts, but not rain itself.
silver marten
Same with snow. Oh and the wind has to blow just the right way sometimes
leaden arch
hello ! I came across an old RC car which I want to modify to use the RPi. Looking at the circuit, seems to be that the component (circled in black) is the reciever (radio). I want to switch this reciever out and instead pass the signals from the RPi. But I am not so sure how to replace the reciever. Really appreciate any pointers. TIA !
primal warren
Yeah, the circled bits look like the RF section, but I'm guessing the CMOS gates below it do some decoding. I'd eyeball the large transistors on the left (Q13-Q16) and see what's driving them. I'm guessing the smaller TO-92 transistors near them drive them in an H-bridge configuration. If you trace the inputs (bases, or maybe gates) of those transistors, they probably lead to the CMOS chips (which are all standard and easy to look up). You can probably hook the RPi to those gates, but you'll probably need a level shifter of some sort, as the RPi uses (and can only survive) 3.3V signalling, and those CMOS gates probably run at a higher voltage. The good thing is that CMOS has high input impedance and is easy to drive.
leaden arch
Thanks @primal warren ... that's a lot to learn for me. the other option is to rip out this entire circuit and drive the motors through via an h-bridge. the back motor is straight forward, two wires. But the front servo seems to have 6 wires ... 2 of which are for power, not so sure what the other 4 are for ... i read up a little online, possibly a potentiometer or some sort of feedback.
primal warren
Six wires, that's a little daunting. I'm not sure what the other ones are doing. You're right, though, sometimes it's easier to just replace the circuitry instead of try to reverse engineer it to figure out if you can re-use part of it.
restive fjord
@normal drift jerryn
do you know why my lora is not sending a long message?
it sends it the first time
but not the second time
normal drift
How long?
@restive fjord sorry, but I won’t be able to look into this until the weekend. Post any information you think might be useful and I’ll look at it when I can.
restive fjord
ok
normal drift
@restive fjord can you post an exmaple of the issue you are having? How long is the message?
restive fjord
i got it working. thank you. if you have time do you mind trying out something else for me?
normal drift
@restive fjord sure - what are you trying to do?
ah -- I saw this in #help-with-projects and I think that is a better channel for it -- I think you'll find more people there familar with this.
restive fjord
okay thanks!
restive fjord
@normal drift do you know how far rfm9x radios can reach?
I have simple wires attached to them.
primal warren
I built some RFM95 into a cosplay prop, and tried operating it from across the convention center, and it worked fine (434MHz, +13dbM, simple wire antennæ).
normal drift
I have not done any distance testing yet. On the product page https://www.adafruit.com/product/3072 it says They can easily go 2 Km line of sight using simple wire antennas, or up to 20Km with directional antennas and settings tweakings
silver marten
@restive fjord if you want distance use an antenna designed with this https://www.changpuak.ch/electronics/yagi_uda_antenna_DL6WU.php
As many elements as will boost the db, but too many will decrease db
rapid hearth
@silver marten "As boost the db, many elements as will, but decrease db, too many will. Yes, hmmm." - Yoda There is so much wifi interefence just being in the house.
silver marten
Lol
normal drift
@restive fjord there are so many factors the will impact the range. - are your systems "line of sight" - no walls, no trees, no buildings in between. are your antennae both the exact length specified for your frequency? are they both oriented the same way? Hopefully others on this channel can provide more information about issues regarding range, frequency and antenna performance. If you think the radios are not performing as advertised, I suggest posting to the forums in https://forums.adafruit.com/viewforum.php?f=19 to get an "official" response.
restive fjord
@normal drift they are not "line of sight." antenna lengths are exact.
normal drift
@restive fjord not "line of sight" how? that may have a significant impact?
restive fjord
trees and maybe a building in between
normal drift
I'll defer to the others on this channel with more rf experience than I have, but i think the "line of sight" specification if one of the most critical for long range transmission.
woeful ingot
yes, line of sight is important. especially at lower power and high frequency.
woeful ingot
23 dB @ 433 Mhz trying to attain 1 km?
woeful ingot
I'm not the most knowledgable, but I know that you're going to have considerable power loss at that distance. An online calculator suggest that you will lose 85 dB
primal warren
If you're going to try for 1km with simple antennæ and obstacles in the way, I'd recommend LoRA.
restive fjord
I do have RFM9x LoRa with simple wire antennas(recommended length)
What they're thinking about is either mountaintop to mountaintop, or someone in a valley talking to a mountaintop.
That's your 2km.
Think I don't know .. Switzerland, maybe.
I would expect a half an order magnitude increase over WiFi or BlueTooth range (500 feet would be pushing it pretty hard).
I give BlueTooth 30 feet under optimal conditions. DECT 6.0 about 50-70 feet, when optimized.
WiFi generally under duress gives just enough of a connection to hang for a long time before failure. ;)
I have done quite a bit of packet radio on 2 meters FM (144 MHz band). Simplex. ;)
restive fjord
so its not possible to make my antennas work in my setting?
restive fjord
?
restive fjord
so it will never transmit thru trees and maybe a building?
they have to be in line of sight?
burnt kite
line of sight and max distances usually go hand-in-hand. i have scant practical experience in LPWAN, but if you want distance you might need to switch to active/powered antennae (which is mildly ironic).
silver marten
@restive fjord i suggested a yagi calculator for a highly directional antenna you can make on my last linked url
i am a ham radio operator and designed a few myself
primal warren
I am not at all surprised several of us here are hams.
My first Yagi array was made of bell wire and twinlead, thumbtacked to my ceiling to receive distant TV stations.
restive fjord
The Fire Departments use mad big amounts of power to overcome deficiencies in RF comms.
They also site the repeater's antenna at a considerable height above average terrain.
The older method was to go lower in frequency (about 32 MHz or so, which is way low compared to what they use now).
It was believed (probably correctly) that to go over a hilltop into the next valley, you couldn't go much above 50 MHz.
Anything much above 50 MHz is considered a line-of-sight proposition; the higher you go, the more so that would be the case.
💼
The way Public Service bands (and cellular telephony) works around that problem is by siting their repeaters on the rim of the canyon, as it were -- or at a central, high location.
Notice I've said the word 'repeater' at least twice, now.
2⃣
All that said, 2 Meter FM (145-147 MHz) isn't all that awful in terrain. Quite useful.
The Business Band just above it is useful to the companies that have equipment (and licenses) to operate there.
4⃣
I think people migrated to the 460 MHz band (or thereabouts) mainly because the resonant antennas could be made physically smaller. That's just a guess.
5/8 wave mobile whips are quite common for an antenna design. That's fairly long for 146 MHz. Larsen makes a nice mag mount version of this antenna.
If I were wild-guessing it, I'd think a parabolic dish would be the way to go for any band you could reasonably accomodate, using one (i.e. high enough in frequency to keep the dimensions reasonable).
🌙
Check out 'moonbounce' antennas, for other ideas.
(they bounce their radio signals off the moon .. for real!)
Or any sort of satellite work (yes, they do that, too)
normal drift
@restive fjord there is a bit more information in the guide about range: https://learn.adafruit.com/adafruit-rfm69hcw-and-rfm96-rfm95-rfm98-lora-packet-padio-breakouts?view=all#faq-4
primal warren
Satellites do pretty much win for antenna height. I've been able to listen to the ISS with an HT and an ordinary whip antenna.
normal drift
Satellites have great "line of sight" ! 😉
silver marten
I am glad I suggested this channel 😀
thick gazelle
Hi,
I'm trying to build a high altitude balloon with my own custom electronics. Does anyone know some good radio modules I could use? all the 1w (max) transimitters are over 100 bucks! Please help
primal warren
My usual approach is an ordinary low-power exciter and a separate power amplifier. Note that you will probably need a license to transmit with that kind of power.
thick gazelle
^thanks for the reply. Anyway, you do not need a license to operate a 1w radio that runs at 900 mhz, the maxiumum license free band in the US. Is the amplifier that connects to the low-power exciter an off-the-shelf component? I don't have much experience with rf electronics, and something like this from digi would be nice (the product is discontinued now): https://www.sparkfun.com/products/retired/9411
primal warren
I found it was cheapest to buy a bare amplifier module and integrate it myself. My last high altitude balloon used one of these at 434MHz: https://www.rfparts.com/module/rfpower-mosfet/mosfetpowermod-uhflp/ra07h4047m.html
thick gazelle
so you modified a cheap radio transmitter with the rf mosfet you linked in your post? do you remeber how you wired it up? if not, that's fine, but did you put the connector on the gate of the mosfet? these questions probably sound really dumb, but this is my first project that incorporates powerful radio transmitters so I'm a newbie
If that mod is feasible, could I connect it to something like this from Adafruit: https://www.adafruit.com/product/3072
primal warren
I found an inexpensive breakout board for the RF module, and yes, just wired the output of my small transmitter to its input.
silver marten
915MHz LoRa doesn't do well in woodland does it?
I have to cover 32 acres that are wooded.
I am looking at getting the 433MHz module for use in the ham band
thick gazelle
the adafruit module is 100mw, so do you think it would work well by itself (no external amplifier) for HAB applications?
restive fjord
Even 70 cm isn't very good in terrain. Also most people don't know how to cable for 70 cm properly (it matters a lot more than it does on the 2 meter band).
If for some reason the woodlands were flat (as in a flood plain) that might change things a bit. Generally flatlands aren't wooded, but hills usually are.
VHF (and especially UHF) are chosen for compact antenna design or high bandwidth applications.
6 Meters (50 - 54 MHz) is a nice compromise between HF and VHF.
A 1/2 wave dipole for 52 MHz:
468 / 52 = 9 feet long (108 inches)
Contrast with a Citizen's Band antenna (Part 95):
468 / 27.1 = 17.269 feet (207 inches)
Almost twice the length.
The cheapest way to explore this question is to get a friend (with a license) and put them on the lowest power setting of a 2M FM handheld, and try to converse in the woods at distances and with varying terrain.
Start with highly compromised antenna designs (short 'stubby' rubber duck antennas).
Maybe wear it low (on your hip) and use a remote speaker mic.
On the other hand a portable GPS uses an awfully small antenna, and is acquiring accurate data over a very large distance.
Very low data transfer rate, with that, but they do it.
silver marten
I was going to make 5/8th wave verticals for antennas. the project is to tell when an animal or something moves on my dads land
maybe particle mesh would be better
restive fjord
When you get somewhere past three to five redundant copies of a thing, it is not unusual to ask yourself 'Just what am I doing here?' ;)
silver marten
@restive fjord what are you talking about?
restive fjord
I'm talking about the Turing tar-pit, where everything is possible but nothing is easy.
If you build out five nodes of a network, it's time to check in with your finances as to why you're thinking about building the sixth.
Though I put that at three to five nodes, not five-going-on-six. ;)
crimson granite
Anyone here playing with LoRa?
primal warren
I've done some playing with LoRa. Seems to work pretty well. I'm thinking of doing some range testing with simple wire antennæ.
normal drift
@crimson granite same here -- I've just done some basic testing of lora functionality with CircuitPython and a bit on the Raspberry Pi.
crimson granite
@normal drift what modules are you using?
normal drift
crimson granite
Good choice!
crimson granite
Anyone here able to perform mesh network using LoRa?
primal warren
I haven't tried that, just the simple broadcast style (no base station) setup. I suppose I could give it a try.
crimson granite
@primal warren How would you start doing that?
What modules use you use to build the network?
primal warren
I'd use the RHMesh part of the Radiohead library: http://www.airspayce.com/mikem/arduino/RadioHead/classRHMesh.html
crimson granite
@primal warren what LoRa module are you using?
primal warren
I have a couple of the (Seeedstudio?) shields, as well as a couple of the LoRa Feathers.
I've done most of my experimenting with the Feathers: I can outfit one with a Neopixel wing and battery, park it a fair distance away, and be able to tell at a glance if it's getting my communications.
crimson granite
Great!
primal warren
I should see if I have at least 3 LoRa modules of the same frequency so I can really exercise the mesh functionality.
crimson granite
I am very new to Adafruit boards. Is feather some sort of arduino?
burnt kite
@crimson granite feather is "like" Arduino in the sense that it adheres to a common form factor. The controller boards can be programmed in Arduino, and some have MakeCode and CircuitPython support. The Feather Wings all match the form factor for easily adding sesnsors and such (same as Arduino Shields).
burnt kite
Serial is accessible through USB (kind of). UART on RX/TX is also available.
crimson granite
@burnt kite what modules would you recommend if I were intending to buy boards to play around with LoRa?
primal warren
I'm fond of the Feather boards, because they're more compact than an Arduino but large enough to include extra built-in functionality (like a LoRa radio), they'll plug onto breadboards, and they include battery support (connector, regulator, charger). I think of them as part of the Arduino ecosystem, but with a different form factor.
If you already have an Arduino, there are LoRa shields available, such as this one (I have a couple of these): http://www.dragino.com/products/lora/item/102-lora-shield.html
If you're looking to get started with minimum integration effort, I've had excellent luck with these Feather boards which work with the Arduino IDE and have a powerful CPU and built-in LoRa: https://www.adafruit.com/product/3179
Note that there are LoRa modules available in various frequency bands (433MHz, 868MHz, and 915MHz): to be able to talk to each other, the boards need to be on the same band. The lower frequency boards take larger antennas and give longer range.
normal drift
@crimson granite If you are planning to say with the Arduino IDE then the integrated M0/Lora above is a good choice. If you are interested in using CircuitPython, then I suggest pairing the Featherwing https://www.adafruit.com/product/3231 (or the 433mHz versino) with a Feather M0 Express or even better, a Feather M4 Express. The integrated M0/Lora does not have the external Flash memory device and with CircuitPython, there is very little space and memory avaliable.
crimson granite
@normal drift Thanks a lot!
normal drift
Note: I have not tried the Lora RF95x featherwing with a Feather rm4 Express, yet -- on my to do list! I expect it to be a great combinaltion!
crimson granite
Alright!
@normal drift How easy it is to use a GPS with a featherwing and circuitpython?
normal drift
@crimson granite I have not used the GPS featherwing -- hopefully someone elss can comment - I have used the GPS breakout board with an Metro M0 and Metro M4 and it was fairly straight forward to use as described in this guide https://learn.adafruit.com/adafruit-ultimate-gps?view=all#circuitpython-parsing - for the featherwing - I would expect it to be simialar using this guide https://learn.adafruit.com/adafruit-ultimate-gps-featherwing?view=all#circuitpython-library.
@crimson granite It may be an issue to use CircuitPython with a GPS and Lora radio with a feather M0 - there just may not be enough RAM.
my todo list is growing 😉
Also note that the Circuitpython support for the lora is fairly limited at this time. ONly some basic parts of the Radiohead library have been implemented.
crimson granite
@normal drift That's a good point. I am finding it very difficult to get started with LoRa: I was not able yet to find some good examples, showing how to use LoRa modules, even with Arduino!
Do you have any suggestions?
normal drift
I have found the guide very useful - the radiohead library has several examples: https://learn.adafruit.com/radio-featherwing?view=all#using-the-rfm-9x-radio
primal warren
Here are the two sketches I used to remote control NeoPixels using a LoRa link: https://gitlab.com/bodger/lora-neopixel
silver marten
@crimson granite For the 433MHz LoRa module you will need an Amateur (Ham) Radio license if you are in the USA
crimson granite
@silver marten thanks a lot!
ionic atlas
Am I understanding this correctly? If I use a Bluefruit feather, I can’t use Bluetooth to trigger audio on the music maker wing?
If that’s true, what would be my option to trigger audio via Bluetooth?
restive fjord
@ionic atlas say that again? Not quite following.
Need the PID (product ID, is 3-4 digits at the end of an Adafruit sales page for a specific purchase).
A link to the page you clipped would speed things, too.
(I like the clip, though) ;)
ionic atlas
@restive fjord https://learn.adafruit.com/adafruit-music-maker-featherwing/play-music towards bottom of page 😃
restive fjord
thanks. I'll look!
@ionic atlas I need the doco on the module that has bluefruit. They're asking you to put that PIN 8 into a high impedance state for a reason (to turn off the radio).
I want to know why that's generally a thing to be doing, and the bluefruit doco might say why.
(D8 is curiously also used in conjunction with other stuff, often -- NeoPixel iirc)
ionic atlas
Like the learning guide for the feather I’m using?
restive fjord
Whatever it is that has that Pin 8.
Probably an M0 target board that has a bluetooth module on it.
restive fjord
okay so a 32u4 board. good. I'll look!
restive fjord
In the schematic, in cell B6 of the drawing (the borders have letters or numbers) is 28 8 BLE_CS on PB4 / ADC11.
I just have to trace where that goes.
C1 or D1 on the borders of the schematic:
P0.24 on the BLE module.
It's an internal connection between 32u4 and the BLE module and it seems to play the role of chip select.
I think what you can do (wild guess; may be of use) is turn off the radio only when you need that functionality you wanted out of the music featherwing whatever it is.
Turn the radio back on to receive its instructions.
I do not know how effective a strategy that'd be
ionic atlas
Demo code seems to imply chip select pin is pin 5?
restive fjord
(or why it may be required; it's a bit of a puzzle to me)
haha that's a screenshot! (literally).
Can I see the code? What library and file is that?
ionic atlas
Adafruit vs1053 library -> feather_player
They set pin 8 high in the SETUP section, I suppose there’s nothing wrong with toggling it in the LOOP section, as you state
primal warren
As I pointed out in #help-with-projects , I think that is to avoid electrical noise from the radio causing interference in the audio circuitry.
restive fjord
ionic atlas
That’s it
restive fjord
@primal warren that sounds reasonable to me. ;)
ionic atlas
Yea @primal warren , I posted here before you replied
@primal warren do you think @restive fjord idea of toggling pin off when playing audio and then turning it back on is doable?
Wonder if I’d have to re-pair to my phone every time it toggled
restive fjord
Maybe to do it right you need a second Bluetooth module, for isolation's sake.
Rather, omit the first one BLE module and put them each device on separate breakouts/targets.
primal warren
I'd try just leaving it on and see how it sounds. A Bluetooth module isn't going to create much interference (especially if you're using it in BLE mode), not like a RFM69W or a cellular modem.
ionic atlas
Ok. But a pretty good bet it will at least function? Nothing worse than dropping $30 on something that won’t work for what you need 😃
restive fjord
If you toggle the radio on and off you run into loss of responsiveness issues.
You could for example tell it to turn on the radio 'at the end of a song'.
primal warren
You could always interpose a proto-shield between them to get a little more distance and act as an electrical shield (just ground most of it) (pun intended).
restive fjord
And give up more nuanced control (rewind, fast forward, skip &c)
ionic atlas
Yeah I only need “play track 1, 2, 3”
restive fjord
@mad they brought up the subject in the Guide by intimating the end-user was going to marry these two boards in the first place.
So the Guide author(s) presuppose people want to use this wing with a BLE-enhanced target MCU board, I think.
ionic atlas
And it WILL have a protoboard in between already due to the nature of my project. What a crazy random happenstance 😃
@restive fjord where in the guide are you seeing them specifically talk about ble? I’d like to follow along
primal warren
It does say "or LoRa or RFM69". I'm guessing all of them use I/O 8 for enable.
ionic atlas
I’ve used all 3, they do
Just making sure the music maker wing doesn’t need pin8, for some obscure reason, to work 😃
restive fjord
This is all very confusing to me. There's extra stuff I don't (yet) know about.
I'm seeing code in the lib's main .CPP file that suggests you can opt in for hardware SPI and that may explain the three CS signals. ;)
I think D8 is always wired to the BLE modules when you have a target MCU as well as a BLE module on the same 'Bluefruit` target board (w/included MCU).
This is also where NeoPixel is connected, on boards that have an onboard NeoPixel (D40 is used on the Uno/Metro style form-factor for that use).
All I'm saying there is that D8 seems to be a 'spare' in their overall design strategy; on some boards it's for the NeoPixel and on others, for turning the BLE radio on or off.
I'm far from understanding the presence of three CS signals/lines.
Adafruit VS1053 Codec Breakout and Music Maker Shield
That lib is for a music player.
@cobalt jasperDicola talked about this board and said people sometimes overlook its extra functionality that it has, by booting into
.. a special MIDI mode that you can boot the chip into that will read 'classic' 31250Kbaud MIDI data from the UART TX pin and act like a synth/drum machine..
primal warren
That's how SPI works: there's a CS lead for each peripheral.
restive fjord
Right. My graphic LCD uses it.
I'm thinking three chip selects implies three chips. ;)
primal warren
I'm guessing one for the radio, one for the SD card, and one for the MP3 decoder.
ionic atlas
I think so 😃
restive fjord
XDCS - this is the VS1053 data select pin
DREQ - this is the VS1053 data request interrupt pin
MP3CS - this is the VS1053 chip select pin
SD CS - this is the SD Card chip select pin
from:
https://learn.adafruit.com/adafruit-music-maker-featherwing/pinouts
Well, it looks complex to me.
I think you will have to take the risk and experiment.
I know sometimes microelectronics looks retail-friendly, but it's not really.
There's an army of people attempting to stand between you, and complexity. ;)
Also, Adafruit has a reputation for making statements that stand the test of time.
If it says 'make sure to' do x, then you need to do x, and live with the consequences.
I can't think of an instance where that's been overturned, later.
They put it in there to help you, not obstruct you. ;)
ionic atlas
But their statement is obstructing my Bluetooth! 😉
restive fjord
Well yes and no.
They want the novice to succeed as quickly and painlessly as possible.
They want you to get immediate use out of your purchase.
ionic atlas
What if I don’t mind severe pain, as long as it’s as quick as possible? 🤔
restive fjord
Look at the interrupts code and also note the 32u4 is listed specifically as incompatible with background stuff (unlike other target boards used to control this module).
I loved the old 8-bit stuff but for newcomers I'm constantly baffled that they choose old 8-bit platforms that are pretty much legacy hardware at this point.
primal warren
Ah, you're right, the VS1053 does have 2 chip selects. MP3CS for SCI (command) transactions, and XDCS for SDI (data) transactions. DREQ is an interrupt that's sent from the VS1053 back to the CPU. SD CS is, of course, the chip select for the SD card.
restive fjord
It's not complex once you realize there's a lot of hardware there.
I mean it's complex by virtue of that fact, but they did a good job keeping it simple as possible (but not simpler, as they say).
primal warren
I do wish, when someone says "make sure to do", they had a link, footnote, or parenthetical comment explaining why, so I could make an informed decision as to whether it applied to my (often unusual) circumstance.
ionic atlas
So I couldn’t use an m0 Bluefruit either? Prertu much SOL?
restive fjord
They just don't take the time to do that. Never have taken that approach across the board. If you get one of those, count your blessings.
They move fast.
The forum I think is where you get that fill-in information.
Occasionally, here, from the (real) developers.
I've gotten very good info from the forum (by asking a very good question).
Also, in filing those discrepancies in github.
primal warren
Yeah, they do move fast. I should probably start submitting pull requests for things I've found and worked around.
restive fjord
It's work but yeah, I agree (in principle).
ionic atlas
If we could only close ladyada and ship her in every box 😃
restive fjord
I've filed one issue (it's in the seesaw code).
I don't know how she endures all this in the first place.
primal warren
I just missed a chance to meet her a while back.
restive fjord
I think I'll spare her the honor, myself. ;)
ionic atlas
All she has to do is make every board compatible with every other board.....how hard could it be!? sarc
restive fjord
Jim you may very well be the first person (you've ever heard from, at least) to integrate those into a project.
.. move over, Neil Armstrong ..
ionic atlas
I’m going to have to science the sh*t out of this....someone get me some sliced potatoes and stand back! 😃
restive fjord
just separate BLE from MCU and add magic foo in-between.
I like 'bodger's theory about noise here.
ionic atlas
I could use an external audio fx card and connect to the ble feather via serial for control....
Not as clean from a stacking standpoint, but it would work
restive fjord
Well radio and audio (both) are susceptible to noise you can notice.
you need a digital input to your human hearing. ;)
primal warren
For your amusement, something I built a while back with BLE, WiFi, GPS, inductive charging, and (ONOZ) cellular. Noise is totally something that can bite you.
ionic atlas
Oh I know. I’ve gotten so frustrated with these audio cards because all the pictures show them powered by a usb power supply. But when I do the same, the switching noise gets amplified.
restive fjord
I've set aside projects simply because they make a noise my good radio hears, and I didn't want to solve the noise issue (because I wasn't sure it was something I could do without help, if at all).
Shortwave portable receivers are usually sold with non-linear supplies.
That baffles me .. until I realize many people will enjoy them on the lower bands with strong local signals present.
I got to duck back into the woodwork, here.
stuph needs doing
ionic atlas
Thanks! Enjoy your stüff
primal warren
I'm all too familiar with the Morse code like buzz that happens when someone leaves their cell phone near low level audio signals. I'm also familiar with the interference cheap LED lights, USB power supplies, and the like make in radio receivers (especially sensitive/wideband stuff like shortwave and ham radios).
primal warren
Those silly people neglect to ground their hats!
ionic atlas
Ding ding! When I see a foil hat in a movie with no ground line I yell “FAKE FAAAAAKE!” In the theater
I’m sure people appreciate me pointing it out
primal warren
Remember those stickers that were for sale for a while that claimed to boost your cell phone's reception? I bought a pile of them, with the intent of making a satirical video, showing putting one on, getting better signal, putting 5 on, full bars, then putting like 50 on, having the backlight glow EXTRA BRIGHT, followed by the phone exploding
ionic atlas
Wait.....those don’t work!? But the guy who sold me my power balance wristband ensured me the stickers DID work!
primal warren
Heh, I was at a party once where someone was hawking those bracelets. Unfortunately for them, I have some knowledge of both physics and sleight of hand. She did this elaborate trick (which I saw right through) to demonstrate how the cell phone was weakening the body. Then I showed her I had popped open the case, palmed the electronics, and she had been demonstrating with an empty plastic case!
She mumbled some nonsense about how the plastic was holding residual bad juju or some such, but she had pretty much lost the audience by then. I proceeded to explain how her "strength" trick worked.
ionic atlas
😃
misty crow
Hi, new to the server. Was wondering if I could get some guidance. I'm trying to make a box (field unit) that can log wifi and bt macs when dark, requested APs, and send that info to another box that has internet access and can send an email. The field unit would also need gpio for a light sensor, pir sensor, and to blare a piezo alarm and possibly lights. One of the issues is that the field unit is in the middle of a field a half mile from any power so a) wifi transmission is useless and b) it'll need battery + solar. Ideally in a smallish form factor. I have a technician license so I think I could use 10m /28.000-28.070 MHz CW to transmit the data. There'd be very little, very seldom, but it'd be important when there's data to send. I saw the Adafruit SI5351A today and thought it could be used for the rf generator before the amp/transmitter. I think the email relay could be a pi zero w, but could use some advice on how to capture and interpret the incoming CW.
primal warren
Sounds like a job for LoRa.
misty crow
Hmm, I'll take a look at the RFM95W breakout.
checking out Pycom LoPy 1.0 as a possible all-in-one for the field box
tiny dust
so i have some questions about designing my SDR
[22:03] <hatsunearu> hihi
[22:03] <hatsunearu> ------------ so i was designing my SDR
[22:03] <hatsunearu> and i was wondering if i feed a digital clock into my downconversion mixer, the harmonics will downconvert stuff around its clock frequency
[22:04] <hatsunearu> like, my SDR will work down to 1MHz, and if i have any second harmonics, then i'll have downconversion products that are from 2MHz
[22:04] <hatsunearu> and the 160m ham band is wide enough that if i tune down at 1MHz i'll get some stuff at 2MHz
[22:05] <hatsunearu> i can't put 2MHz in my stopband to remove this chance
[22:05] <hatsunearu> im not sure if this warrants a DDS clock generator instead of a simple digital clock generator
the current design is like this
ant --- 1-30MHz bpf --- LNA/preamp --- band-select BPF ---
the band i'm concerned is the 160m ham band
which is like 1MHz-2MHz approximately
if my LO is tuned at 1MHz and has 2nd harmonics, then i'll have 1MHz stuff and 2MHz stuff in the IF
silver marten
@tiny dust so, what's your question? You want to use your sdr to listen to the 160meter ham band.
I use sdr console
The 160meter band is 1.8MHz-2MHz
young cove
@tiny dust if it's a superhet design, then you need to choose an LO that's well above the bands you want, so you can use bandpass filters or low-pass filters to get rid of the unwanted mixing products
if it's a direction conversion design (LO = tuned frequency, so downconvert to audio baseband), then not a problem
misty crow
LoPy4 doesn't support wifi promiscuous mode, but the ESP32 that's used in the LoPy4 can do it. I'm not experienced in Linux, C, editing toolchains and header files, linking and compiling stuff... I've seen the words but have no experience with it. Does anyone have a recommendation for a Windows/C# person to learn how to edit an existing firmware (I think specifically esp_wifi.h?) for a LoPy4 chip to enable features supported by the ESP32 SoC on it, and to make this functionality available to its MicroPython front end? I have some experience with Arduino and ATTiny85s, but I only used the Arduino IDE and built-in/library stuff, never refactored any under-the-hood stuff.
Is it going to be a matter of, "Go learn everything, try a bunch of unrelated stuff, then attempt the thing you're interested in. Good luck, hope you don't brick your board"
silver marten
@young cove thanks Dan. I haven't studied superheterodynes much. I just take them for granted at the moment. I needed to know the basics for the Amateur Extra test and that was it. Time to revisit it.
@misty crow I am not that good with code. That would be a good question to ask in #help-with-projects
limpid citrus
Anyone have experience with LoRa modules?
silver marten
@limpid citrus several people do. I intend to in the near future. @normal drift or @primal warren might be able to help better than me at the moment.
If you have questions about antennas or ham radio related topics I should be able to help
primal warren
I've played with LoRa modules a little. They work surprisingly well.
tiny dust
@young cove why is the latter not a problem
mine's like pseudo direct conversion
i don't convert down to AF, i convert down to a lowish frequency (250khz) and sample right there
also 1.8mhz-2.0mhz, yeah, but i didn't want a band pass filter that's so narrow that limits the passband, i wanted a bit more than 1.8 to 2.0, so i chose 1.0 to 2.0
and if my LO was at like 1.0MHz then the second harmonic would be downconvertting stuff at 2.0
how is this not a problem?
someone did mention that the 2.0 clock will have a phase relationship that is not quadrature so the mixing products from the harmonic would end up cancelling
but i couldn't see how
silver marten
@tiny dust I don't know enough to help, but I am sure there is someone who can
tiny dust
ok
i talked with them
turns out worrying about 2nd harmonics is not a concern beacuse the 3rd harmonic will kill me unless i have a really good band select filter
so i decided to just use DDC generated LOs
and from SPICE simulations it looks like a very low LO drive is good to keep the LO from getting contaminated with harmonics
100mV gave me 29dB less on the 3rd harmonic downconversion
sqaure wave gave me like 10dB
useless
silver marten
@tiny dust sine waves are what radio waves are made of
Plus 10db is pretty darn good.
Every 3 db is a double in power. By the way do you have your ham license?
The antenna makes the ham. As the saying goes
tiny dust
yes i have a ham license
amateur extra
10db is not good lmao
-10db of spurs
that raises the noise floor by a lot
and i assume the 5th, 7th will all contribute -13db, -15db each
tiny dust
welp
switching mixer still has ass performance
and DDS 30MHz sinusoid is still ridiculously high
silver marten
I am Amateur extra as well. By chance were you in Lexington ky for field day this year?
Just hoping that the new ham that got all three classes in one fell swoop found his way here after I told him about this wonderful place
primal warren
I'm also an extra (the day I took my exam was a weird day, but I passed).
tiny dust
@silver marten nope, im not in the US for the time being 😛 (i will be back in a year)
i was technician and then in my second exam got to extra
silver marten
@primal warren I'd like to hear the story
primal warren
I woke up, had a root canal, joined up with a friend, drove a couple of hours, studied for my exam, spent the night, woke up, went to an emergency preparedness exercise, drove a couple more hours, took my exam. A bewildering whirlwind.
restive fjord
From #general-tech at this time of day on this date. Discussion was about conversion of (1.2 GHz?) wireless router (WiFi) to amateur radio 2 meter FM telephony operation, with split frequency operation (for repeaters).
pallid seal
well, it actually changed into, is there a way I can build a 2 meter ham radio, using makeshift equipment
restive fjord
I mention that wireless routers are optimized for a different emission type (not FM narrowband telephony) on a completely different radio band (not 146 MHz).
pallid seal
is there a way I can make a 2 meter radio using MacGyver bs?
restive fjord
The good news is that iirc you can legally operate good equipment you construct on most (if not every) amateur frequency allocation.
pallid seal
technician class still has limits
restive fjord
You can run SAMD51 at 146 MHz.
That would create a frequency-determining component. ;)
pallid seal
so.. what I wonder is.. is can I plug an antenna into my laptop, and use my laptop as the brains of the transciever?
restive fjord
In some respects, I would suppose so.
The usual method (now dated?) was to use the sound card for some things.
Probably for its DAC (digital to analog converter).
pallid seal
my laptop does have an audio port(a 3.5 4 pinned audio jack that can handle audio input and output)
restive fjord
Also it has ADC (analog to digital converter) to be used as a source (as in a homebrew instrument of some sort).
pallid seal
and I could build a splitter cord, that splits the jack into two 3 pinned 3.5 mm jacks, one for microphone, one for speaker output
restive fjord
You could create a software TNC (terminal network controller) for Packet Radio on a computer, which talks via the audio ports to a 2M FM transceiver, to send and receive packets over the air.
In that role the computer is generating FSK (frequency shift keying) of some type.
restive fjord
Old issues of QST (a magazine) and the ARRL Handbook give detailed plans (now outdated) to build your own transmitter and receiver.
pallid seal
hmm, maybe I should just wait for christmas, when my dad will just buy me a proper setup
I was just really wanting to get on the air,
restive fjord
I don't worry about licensing (even a little). If you give my callsign on the air and you give a fake callsign for your station, I just don't answer and (if annoyed) turn the knob to another operating frequency on my rig. ;)
pallid seal
but that;s illegal
restive fjord
baofang (spelling) is very popular and is 60 bux or so for 2M FM handheld rig
Just tell the dad to front you the present now and you'll wash his car for christmas eve. ;)
baofang (spelling) is very popular and is 60 bux or so for 2M FM handheld rig
pallid seal
it's a case of he flat out doesnt have the money to spare to buy it
restive fjord
I got science presents every christmas for about three years running.
After that I Think I was expected to fund my own interests. ;)
(then got like a pair of socks for christmas hi hi)
pallid seal
as he is currently going through some financial issues at the moment, that he will be able to clear up by the time christmas would roll around
restive fjord
Go visit some ham shack nearby (they have clubs and club stations in some communities).
Once you're on the air you can casually mention that you're radioless.
pallid seal
I dont think I have one of those near where I live
I have an MTC shop that sells radios
but no ham shacks where I can use their radios
restive fjord
They're getting harder to find all the time. ;)
We used to do saturday morning emergency preparedness drills and stuff like that.
Also Civil Defense on Wednesday nights. That was MARS iirc (military affiliate radio service, just above the corresponding ham band I think)
Also a high school radio club. We had 40 meter operation (among other bands).
I used to work CW during free periods at the school (during school hours).
pallid seal
but yeah, I think it'd just be best for me to wait for my dad to be able to get me a radio..
cause I'm really not skilled enough to build one atm..
restive fjord
Transmitters are an order of magnitude easier to construct than receivers are.
Making a decent radio receiver is a fairly advanced project.
Now with digital I have no idea how that changes.
pallid seal
yeah, but some people do know how to make them, and they do sell them
restive fjord
But for analog circuits (circa 1975 anyway) it was quite a challenge to build a useful receiver.
pallid seal
so I think it'd be smartest for me to wait for my dad to just buy me a proper transciever
instead of making some eldritch macgyvered abomination out of scrapped parts and duct tape
restive fjord
Haha.
pallid seal
cause most devices I build are eldritch macgyvered abominations
restive fjord
The call number for ham radio in the public library is 621.384
pallid seal
ok..
pliant garnet
What is an antenna insulator when referring to ham radio?
silver marten
@pliant garnet it is typically a non conductive (ceramic) piece that the wire of a di-pole ties to, to tie it off to a pole or something
pliant garnet
Is it used for dipoles only?
pliant garnet
What does it do?
silver marten
It isolates the antenna from the tie-down wire
They can come in different shapes too.
pliant garnet
Oh, so it doesn't short out to your radio?
silver marten
Yes, it keeps the antenna from looking electrically larger. And thus making the SWR higher than 1:1
Sorry miss read your question
pliant garnet
No problem. So is it considered as a safety feature?
silver marten
Yes in a way. I would assume it is more of a antenna saver than anything
pliant garnet
As it protects your radio as well from electrical current? What is the difference between having a ground place and this?
silver marten
So, this isolator would go between a tree and the antenna with a wire connecting the two
It would prevent ground so your antenna doesn't short
And so it doesnt snap
pliant garnet
and can it short when there are lightning strikes or something like that?
silver marten
You would want to unplug your antenna when there is possible lightning. It will greatly reduce the chances of a direct strike. You are removing the antennas path to ground when you unplug it from your radio, unless you have a lightning arrestor that is grounded then. SHAZAM!
pliant garnet
Wait, so the main reason for having an antenna insulator is to protects your antenna against high currents passing into it?
static snow
@pliant garnet The primary reason for an antenna insulator is to isolate the antenna from other conductive objects that may detune it. Detuning the antenna means that it won't be efficient across its designed-in frequency range. The second reason for an insulator is to provide safety when subjected to static electricity build-up or lightning strikes. Protects the radio and the radio operator. A lightning arrestor or disconnecting the antenna during a storm, as @silver marten said, is a must for outdoor antenna. Masts and supporting guy-wires should have a reliable connection to earth/ground as well to keep nasty weather-related voltages from entering the radio or the home.
silver marten
@static snow thanks
pliant garnet
So antenna insulators affects the SWR positively.
static snow
@silver marten what you said -- just in a slightly different way.
silver marten
More consise
static snow
The insulator is a necessity -- part of the antenna design.
silver marten
@pliant garnet yes
pliant garnet
How do antenna insulators differ from ground planes?
static snow
The conductive part of the antenna and the signal cable to/from it provide the SWR advantage. The insulator just keeps other conductive objects from lengthening the antenna.
pliant garnet
And what are the other necessities needed for an antenna?
Ohh, so an antenna insulators just stops the SWR from going up.
pliant garnet
Thank you @silver marten for the explanations.
silver marten
You're welcome
GN
I will come back tomorrow if there any unanswered questions
Er later today
static snow
A basic antenna is just a wire cut to respond to the frequency that you want to receive/transmit. The ground plane, in most cases the earth, is needed to act as a reference for the voltage that an incoming radio signal places on the antenna.
pliant garnet
Is it another safety feature?
static snow
There's an explanation of antennas in one of JP's learning guides -- hang on and I'll find the link for ya.
pliant garnet
Ok, thank you.
static snow
Simply stated, the ground plane is needed so that the antenna has a reference voltage -- you can't receive a signal or measure a voltage, for that matter, without two wires: one for the signal and the other as a reference point for that signal voltage.
pliant garnet
Ohh.
static snow
That's why batteries have two terminals, too.
pliant garnet
Yes.
static snow
About half-way down in this chapter of JohnPark's guide is a section about antennas and how they work with incoming signals. It's about AM radio (relatively low frequency radio-wise), but the concepts are the same for any frequency. https://learn.adafruit.com/am-radio-morse-code-paddle?view=all#am-antenna
pliant garnet
That's a very useful project. Thank you so much @static snow I will have a lot of things to learn.
static snow
Glad you're interested -- it's all very learnable.
pliant garnet
Yes, the radio world is huge.
static snow
Do you have a project in mind?
pliant garnet
I am planning to get my license for amateur radio.
I am in Malaysia btw so everything is a little different.
static snow
Are there any local amateur radio groups near you?
pliant garnet
There are a few and I plan to join them soon.
static snow
Good -- they usually have study guides -- and most members are very happy to help folks get a start.
pliant garnet
Yeah.
I did some practice tests just now.
I need to get familiar with those block diagram questions.
What connects to what.
static snow
Yes, and which way signals travel between blocks. Best of luck to you, Karl. Let us know if you have more questions.
pliant garnet
Thank you!
static snow
You're welcome.
pliant garnet
One of the things I need to know are filters.
Band pass filters, high pass filters, low pass filters etc
static snow
In concept or do you need to calculate component values?
pliant garnet
In concept and in the block diagram questions. Where it is like: band pass filter -> (something) -> (something)
static snow
So do you already understand what each of those filters do with regard to radio frequency signals?
pliant garnet
I know some basics of it like that a high pass filter lets frequencies higher than the cutoff frequency pass through.
static snow
That's good.
pliant garnet
And the same with a band pass and low pass.
static snow
Do you know why they're important for processing radio signals?
pliant garnet
But I need to know what those filters apply for in regards to radio.
That's something I need to know.
static snow
Without seeing the specific questions, I can only share some general concepts.
pliant garnet
Sure, that could work.
static snow
If you think about incoming radio signals as everybody transmitting on a bunch of frequencies at the same time, you would use filters in the first stage of the receiver to eliminate signals outside of your range of interest. Otherwise its like trying to listen to an orchestra where everyone is loudly playing something different, all at the same time. It would be difficult to pick out the flute from that.
A combination of filters would select a frequency region of interest by only passing through the signals you want to hear.
pliant garnet
Ohh, so I guess it is like a water filter, filtering out the things you do not need and keeping the things you need.
These are some of the questions relative to this.
This question is more electronic based.
static snow
Very similar. The larger the mesh on the filter -- the more stuff gets through. The smaller the mesh, the more selective the water filter becomes.
This example is dealing with the incoming 50 to 60Hz power line frequency. Is it 50Hz in your area?
Do you understand what a power transformer does in this case?
pliant garnet
I think it is 50Hz in my area.
The transformer changes the input voltage to a more useful voltage.
static snow
Yes. It only works with alternating current (AC) for both the input and the output. That means that the output is a voltage that changes polarity from positive to negative (relative to the circuit ground/common) at the rate of 50 cycles per second.
Most electronic circuits need direct current (DC) power to operate, so the first step is to eliminate the part of the AC wave that's negative or positive -- just one of those -- so that eventually the output of this power supply is either a stable positive or negative voltage, whatever the system on the other side of the Output needs.
Did you already know that concept? Have you studied rectifiers yet? (We'll get to the filter in a minute.)
pliant garnet
So I have heard of full bridge and half bridge rectifiers? @static snow They change AC to DC?
primal warren
Sort of: they change AC to pulsating DC.
pliant garnet
So what is the difference between a full bridge and half bridge?
And by pulsating DC, does it mean a sine wave?
primal warren
A half bridge only requires two diodes, but needs a center tapped transformer. A full bridge requires four diodes, but doesn't need a center tap. The output is like a sine wave, but with the negative half flipped to positive.
pliant garnet
Do they both turn AC into DC?
primal warren
They both turn AC into the sort-of DC pictured.
pliant garnet
Ohh, ok.
I got a question about FM bands and VHF/UHF.
Is VHF part of the FM spectrum?
primal warren
FM is a modulation technique, VHF and UHF are frequency bands, so they aren't necessarily linked. However, if you're asking if FM broadcast is in the VHF band, yes, it is, squeezed between VHF TV channels 6 and 7 (in the US, anyway).
pliant garnet
But for amateur radio, there is an VHF allocated frequency range?
What is FM used for in amateur radio?
primal warren
There are two VHF bands allocated to amateur radio, 2 meters (144-148MHz) and 1.25 meters (222-225MHz). Narrowband FM is used in parts of both of these bands, as well as the UHF and microwave bands.
pliant garnet
So FM describes there bands specifically in amateur radio?
primal warren
Sort of. While FM is generally only used on the VHF and higher frequency bands, it doesn't really refer to a specific band.
Lots of info available here: http://www.arrl.org/band-plan
pliant garnet
What is the difference between Narrowband FM and Wide band FM?
Like SSB, is FM something you can enable on a radio?
primal warren
As the names imply, it refers to how much bandwidth the signals occupy. Broadcast FM is wideband (5kHz maximum deviation, 16kHz bandwidth), while amateurs use narrowband (2.5kHz max deviation, 11.25kHz bandwidth) FM.
pliant garnet
Ohh, so amateurs don't touch wideband FM at all?
primal warren
Yes, FM is another emission mode (F3), and many radios support it as well as SSB (J3), AM (A3), morse code (A1). Amateurs don't use WFM very much.
pliant garnet
So what is FM used for in amateur radio?
I know that SSB is used for more range while sacrificing the sound quality as the power is concentrated on one sideband only.
And I know that FM sound quality is good.
primal warren
Yes, FM is for short distance, high fidelity, AM is longer distance, lower fidelity, SSB is even longer distance, even lower fidelity. All are used for both voice and data.
Similarly, FM eats a lot of bandwidth, AM less, and SSB still less.
primal warren
FM is generally not used in HF, aside from a couple of RTTY modes. There are AM pieces in the 80, 40, 20, 10, and 6 meter bands.
There's not a lot of bandwidth available in the HF bands, so narrowband modes are much preferred.
pliant garnet
Why would I use AM rather than SSB in those bands? For better sound quality?
primal warren
Yup, it's easier to tune an AM signal, it sounds better, and there are a few receivers out there that don't support SSB.
pliant garnet
Ohh, ok.
And does the same apply to VHF/UHF for FM, where if I want better sound quality?
primal warren
Pretty much, but on the VHF/UHF bands, there's a lot more bandwidth available, so FM use is common there.
primal warren
There is even full bandwidth television on amateur UHF bands (you can find slow scan television on other bands, since it doesn't need nearly as much bandwidth).
primal warren
I don't see much AM use in VHF/UHF.
silver marten
The 6 meter band is vhf as well
pliant garnet
I know that SSB can be used for VHF as well, but can SSB be used in UHF?
primal warren
It can, although not all transceivers support it, it's not mentioned in the band plan for 70cm, but it is listed for some of the 23cm and 33cm UHF bands and some of the higher frequencies.
pliant garnet
So SSB/AM is more common is HF/VHF and FM is more common in UHF/VHF?
primal warren
Yeah, I'd say so.
pliant garnet
Which VHF band is SSB common in?
languid phoenix
I'm seeing 144.200-144.275 listed as general SSB operation in the ARRL Band Plan for 2 Meters
http://www.arrl.org/band-plan
silver marten
The ARRL Band plan for 2 meters and higher freqs are for the U.S. your country most likely has a different band plan. As far as I know Europe doesn't have 2meters allocated to them. I only know this because of the stink that was raised about the EU version of my FT-991 didn't have the ITU region 2 freqs available to them.
pliant garnet
Is it possible to use no modulation for VHF/UHF?
And with VHF, not a lot of radios have SSB for them I think, so I guess FM would be the path to go.
silver marten
Yes, but Don't know why you would want to.
The all mode hf radios that have vhf/uhf built in have ssb for those freq ranges
pliant garnet
Have you heard of the Baofeng handheld radio?
silver marten
Yes
pliant garnet
Those radios do have FM for the VHF/UHF, right?
silver marten
Yep
pliant garnet
But you can choose to not select it?
silver marten
It is fm only
pliant garnet
Oh, so FM applies to everything on that radio?
pliant garnet
Are there are other types of modulations on that radio or only FM?
silver marten
Only fm. You can hook your phone up to it or a TNC and do digital modes
Look up APRSdroid
pliant garnet
So is modulation made to enhance a factor of a signal?
I have heard of APRSdroid, the app for your phone.
silver marten
Fm is a 50% duty cycle and has high fidelity audio but has low range. AM is 100% duty cycle and has richer tones. Can be used to talk around the world and locally. AM is a carrier and 2 side bands the carrier holds all the information. With SSB one sideband snd the carrier of the AM signal is suppressed and all the information is put into one sideband. I forgot the % duty cycle of SSB.
Take a look at wolphi link apps
restive fjord
No modulation is called CW and is allowed on all Amateur frequencies.
Most people call it Morse Code, I think.
CW means Continuous Wave.
The interesting thing about strong radiated AM signals is that the audio section of the transmitter has to provide significant power (often measured in tens of Watts or more).
pliant garnet
CW is good for QRP portable I guess.
pliant garnet
So practically everything voice is modulated?
silver marten
@restive fjord thanks for clearing that up
@pliant garnet everything digital and voice is modulated
pliant garnet
And what are the main types of modulations associated with amateur radio?
silver marten
There are many modulation types used in ham radio. PSK31 (phase shift keying) is one of the main hf digital modes in use now. There is FT8 (the other main hf digital mode) AFSK (audio frequency shift keying) used in APRS and a few other things.
There are proprietary digital modes called D-Star (icom/kenwood), DMR(multiple brands), and C4FM (Yaesu)
pliant garnet
What is the difference between a counterpoise and a ground plane for an antenna?
pliant garnet
Don't they both ground?
silver marten
The radials on a ground plane are it’s counterpoise.
Counterpoise is whatever is attached to the ground or shielding on coax
pliant garnet
So a counterpoise is part of a ground plane?
I thought they were two separate accessories.
pliant garnet
And what is the mode RTTY? Is it a popular mode to be used by amateurs?
primal warren
A ground plane is a kind of counterpoise, however just hanging a random wire from the antenna on an HT also constitutes a counterpoise (and works surprisingly well for such a trivial addition).
There are lots of RTTY modes, they're various ways to send digital data over a radio carrier.
They're fairly popular, and have several specialized variants for different purposes.
pliant garnet
Oh, if a ground plane is meant to be able to get a reference point with the antennas, then what is a counterpoise for?
primal warren
I find it useful to think of a counterpoise as something for the antenna to "push against". Again, a ground plane is a type of counterpoise.
pliant garnet
Oh.
restive fjord
Is there any small chips that can send (and a different chip to receive) data about 5-10 feet (1.5-3 meter) abouts? I have a propreitary made one I'm trying to mimic, it's 1cm x 1cm about. Transceiver is fine too but I figure that small might need a transmitter and a different receiver
been looking for a while only thing I found was:
https://www.ebay.com/itm/RFM69HCW-915Mhz-20dBm-HopeRF-Wireless-Transceiver-Module-for-Arduino-SX1231/202353041057
I kind of wanted smaller
pliant garnet
Smaller????
restive fjord
it's an adjective meaning of a size that is less than normal or usual.
pliant garnet
That will be very hard to find then.
Have you looked into LoRa modules?
Or those 315MHz/433MHz modules?
restive fjord
yea I looked all over, frequency doesn't matter. that one does 315 etc as well it seems.
I just have to send like 10 bytes per second hahahaha, but my dreams of being small doesn't seem good
primal warren
You can get a little smaller with something like an nRF8001, but that's an entirely different protocol/technology. Those little boards have become a de facto standard for RF links, and are available in a variety of frequencies and protocols, but they're all that size.
TI makes some little modules like the CC1000, but they aren't much smaller either.
restive fjord
CW is a direct control of a transmitter's radiated signal, by turning it on or off (full power, or no power at all).
The CW carrier signal (at the specified RF frequency of operation) has no bandwidth, per se.
On an oscilloscope, CW looks like a sine wave at an RF frequency.
At audio frequencies (as in a CW sidetone) it looks identical -- you would need to look at the oscilloscope's time base to distinguish a code practice oscillator's waveform from an RF radiated signal bearing CW intelligence -- as otherwise they look exactly the same.
The (relatively simple) FM equivalent to CW is to kerchunk an FM repeater.
This is usually commented-on with the voice response of no audio to let the other operator know their microphone circuit is either malfunctioning (no audio) or that (for whatever reason) they failed to speak into it (no modulation).
An FM kerchunk probably looks pretty much the same as an AM signal does, on an oscilloscope.
I have no guess as to which is more efficient; my guess is the AM rig would be more effective here, in putting out a strong signal.
Aircraft radio are often AM modulated because of how competing signals work.
You can usually hear multiple signals on the same channel, if they're of nearly equal strength.
You can also decode SSB (single sideband) by clever use of a second portable receiver, by adjusting it's tuned frequency to that of the primary radio receiver, less (or plus) a little.
The local oscillator of the secondary radio (when closely matched to the operating frequencey of the SSB station) acts similarly to a BFO (beat frequency oscillator) and the two signals mix, which decodes the SSB modulation just fine.
What's interesting there is that neither radio needs an internal BFO (if the radio you were using had a BFO there'd be little point to the exercise).
So this is a way to hear SSB on an AM-only radio!
pliant garnet
Wow, I'm learning so much.
Thank you.
With your mention on aircraft radio and how you can here multiple signals on the same channel, are they all on the same frequency so you can here multiple at the same time?
restive fjord
(can't stay longer; I have stuff to do right now).
I recommend getting an oscilloscope. I picked up one for 80 dollars at a hamfest in March.
Pretty good 10 MHz scope (maybe 25 MHz; I don't remember offhand).
pliant garnet
Yeah, I will plan to get a DSO soon, still saving up though.
restive fjord
The pilots can all hear each other talking over one another, for the most part, unless one is very strong (then it just overrides everyone else due to power alone).
pliant garnet
So full duplex?
restive fjord
On certain frequencies at night you can hear two competing AM broadcast stations at the same frequency at the same instant in time.
No they're each operating simplex (Push-To-Talk).
Full duplex is like the telephone -- both can speak at the same instant without interference (and a different sort of human mind could make good sense of it).
pliant garnet
But doesn't simplex only allow one transmission at a time?
restive fjord
Two 'listening FM` repeaters can mimic full duplex to a third party listening on the output.
Their audio is mixed (somewhere) But the inputs are separate channels.
The two operators key-down on the mic cannot hear on the channel they're key-down on, but there are probably radios they can use to monitor the third channel (the mixed output).
Simplex means single-channel two-way conversation and by its nature only one speaks at a time.
e.g broadcast radio isn't simplex since there's nobody talking back on the same frequency.
simple packet radio TNC's operate simplex in that only one station transmits at a given instant in time
pliant garnet
So in your example, the two operators key-down on their mic at the same time, but cannot hear the rest on that channel, thus, the receiver on its output can hear the two at the same time?
restive fjord
Full duplex on (say) 70 cm is when you can listen while you transmit, on a second frequency.
There's an antenna problem to solve with that.
A simple way to do full duplex is to have a second radio that receives on the same frequency.
With its own antenna.
with that arrangement you use snubber diodes across the receiver's antenna terminals to shunt all that close field radiation to ground.
pliant garnet
Ohh.
restive fjord
'full break in' is very fast transmit-receive switching on a single antenna.
pliant garnet
And if they are doing full duplex, they share the same bandwidth?
restive fjord
So for example if you were conversing on SSB and used VOX (voice-controlled transmission) you would hear the other party when they commented, as any time you weren't speaking, your transceiver would switch into receive mode (very very quickly).
That's not duplex either. It's very fast (efficent) control of a simplex channel by cooperative use and clever transmit-receive switching on both radios.
pliant garnet
Oh, so its due to the radio's fast circuitry in alternating between transmit and receive mode, it mimics full duplex?
restive fjord
Well it's all a matter of timing; if you cannot simultaneously hear and speak it's not duplex. ;)
pliant garnet
Yep.
restive fjord
Generally simplex is a standard two-way radio where while you are speaking, you are not (at all) listening.
pliant garnet
Can that happen with 2m/70cm as well?
restive fjord
Yeah there's 146.52 MHz and that's called "five two, direct".
That's for like when you're not in range of a repeater and need to talk to a friend.
You both tune to that frequency.
pliant garnet
Its the same frequency for transmitting and receiving?
restive fjord
If you want you can operate split-frequency (one on channel A and another on channel B).
Split frequency is the same as using a repeater, only there's no repeater.
Because of that, you aren't both listening on the same frequency.
pliant garnet
So if everybody connects to that frequency, they can talk to you normally.
restive fjord
I don't know what that means.I got to go --I'm late!
pliant garnet
Ok, thank you.
I will carry up this conversation with one of the other guys. Thank you, nis!
pliant garnet
Just read some information on this calling frequency, and it operates by radio-to-radio, on simplex.
silver marten
@restive fjord AM is not as efficient as SSB. AM power is spread out over a 6kHz bandwidth where SSB is 2.5-3kHz
pliant garnet
This is making me slightly confused.
pliant garnet
I have a question regarding amateur radio. Why is it important to adjust your RF gain?
pliant garnet
And does mic gain affect your power output?
restive fjord
@pliant garnet In a word, distortion. (I said 'power' then backspaced over that, hi hi).
The receiver is designed to operate in such a way as to receive the weakest signals it can amplify.
It's the same as a guitar amplifier -- if you crank up the preamplifier, but do not adjust the main power output, the combined amplifiers (plural) won't amplify cleanly.
The preamp on the guitar amp is designed to bring in weaker signals and amplify them more than already-strong signals.
Enough so that you may want/need to bypass the preamp!
A good example of this is a guitar pickup versus a microphone.
I don't know the relative power between those two - - but they may not be in the same range.
Performers who use a multiple input guitar amp for voice work (as well) need to be able to balance voice work with instruments.
restive fjord
AGC (automatic gain control) was a big improvement in radio receiver design.
pliant garnet
AGC, automatically controls your RF gain?
restive fjord
The trick with those receivers was for the operator to know when to use a lot of AGC and when not to.
AGC automatically amplifies weaker signals more than strong signals.
pliant garnet
How could you use too much?
restive fjord
Before AGC you would manually turn down the RF gain when listening to strong signals.
It would distort if it was too strong.
When a signal is really strong (truckers in a parking lot on CB comes to mind) sometimes the circuits aren't enough to attenuate the strongest nearby signals.
pliant garnet
So to just clarify, the RF gain works like an amp?
pliant garnet
Ahh ok.
primal warren
Although on many radios, the "RF gain" control is actually an RF attenuator.
restive fjord
So an antenna with a lot of gain performs better than one with not much gain.
AF gain is the same as a 'volume' control.
pliant garnet
So with AGC in radios, how can it be controlled in the circuitry? Can you manually set how much you want?
And the limits?
restive fjord
Usually there were presets for the AGC for different operating conditions.
Too fast or slow of an AGC is annoying depending on the conditions.
(speed is more a factor here than gain per se)
Equivalent to how fast you can reach for the 'gain' knob and adjust it manually.
Mic gain is for how loud you want to sound on the air. Too much mic gain is harsh to listen to on the other end (at the other operator's receiver).
Too little mic gain sounds underpowered.
Radio (just like light and vision) operates over a very wide dynamic ('changing') range.
3 decibels is a doubling of power.
primal warren
Controlling gain in the circuitry is done in a variety of ways. Sometimes the manufacturer would choose a "remote cutoff" tube and vary the grid bias to adjust the gain. Others would use a pentode, and vary the gain by adjusting the voltage on the screen grid.
primal warren
An ordinary tube would have the grid wound at a constant pitch, so all the current (and therefore the gain) would shut off at once. This was known as "sharp cutoff". The manufacturers began offering tubes where the grid was wound with a varying pitch, so some would cut off while the rest was still allowing current flow. This made the cutoff gradual, and allowed varying the gain. Since the cutoff was (electrically) "farther away", or more "remote", these were known as "remote cutoff" tubes.
restive fjord
Wow!
I didn't realize a grid was wound -- I heard about 'screen' grids and assumed like a screen door (a rectilinear mesh).
I have a JAN 6005W (6AQ5) and two 6BE6 tubes right here. ;)
surreal fulcrum
where I am now?
pliant garnet
Does mic gain affect your output power at all? Is there a relationship?
primal warren
Yeah, tubes were quickly optimized for manufacturability, and a quick and effective way to make grids was to wind fine wire around a pair of thicker wires. https://upload.wikimedia.org/wikipedia/commons/thumb/0/02/VacuumTubeGuts.agr.jpg/600px-VacuumTubeGuts.agr.jpg
pliant garnet
@restive fjord Also, when you came to saying that speed is a factor to adjust the RF gain, how would you know when to turn the RF gain down or up? Is there a major indication by the audio?
Does mic gain affect your output power at all? Is there a relationship and how would you know about the mic gain and how to adjust it?
restive fjord
@pliant garnet when you get on the air and you operate your (vintage) radio, your body just starts reaching for the right knob at the right moment. Same as driving an automobile (and, say, adjusting the broadcast receiver radio in the dash board).
Mic gain has the most effect on radiated AM signals -- as I mentioned, the audio section of an AM transmitter draws significant power and contributes a significant amount of power to the radiated signal.
Typical shortwave mobile radios of a specific vintage had heat sinks on the primary audio amplifier's transistor.
Galaxy DX-939 TDA2003
http://www.cbtricks.com/radios/galaxy/dx939/graphics/dx939_sch.pdf
pliant garnet
So I guess knowing when to adjust your RF gain just comes naturally.
restive fjord
I know a lot of CB'ers who don't understand why there's an RF gain. ;)
(well a few anyway)
A friend of mine was on the air a lot and would drive over to my place, and key down his radio right outside my door.
Peg the meter on my receiver, he did. ;)
restive fjord
They like CB because they can talk the talk that our dyno censors here. ;)
restive fjord
So that TDA2003 is an automotive audio amp for 10 watts -- the CB radio it belongs in only puts out 4 watts of AM power.
restive fjord
Also my iMac G4 has this same chip in it for its audio amplifier.
Almost all the CB radio ops around here have a valid amateur radio license too.
Most are more like CBers than ham, from where I came up from.
pliant garnet
So the amp puts out more power than the radio needs because of the AM signal taking up that 6 extra watts of power?
To put out its signal?
Does this only apply for AM?
restive fjord
I don't exactly understand how the audio power contributes to the RF signal's power with AM.
Very specific to AM, yes.
pliant garnet
Hmm.
restive fjord
You could simulate an AM radio station if you were infinitely fast (like 'Data' on Star Trek) and had access to the 'RF Power' knob on an otherwise unmodulated radio signal.
It is literally amplitude modulated.
You'd be twisting that transmitter power knob to vary the power at audio frequencies.
So, from say 300 times a second to about 8,000 times a second.
surreal fulcrum
@restive fjord or FM radio station?
restive fjord
FM is different. It's a series of different frequencies all about the same amplitude, radiated serially (one after another) and continuously.
pliant garnet
Wow lol.
restive fjord
FM frequency varies at an audio rate.
pliant garnet
Why do some people just turn up their mic gain all the way?
restive fjord
why not? they can't turn it any further, is why they 'only' turn it all the way up. ;)
pliant garnet
Ohhh, haha.
restive fjord
I took a 12 meter SSB rig (a very cheap mobile) and shouted into the microphone (a good D104) and was able, with 12 watts, to be heard in the Ukraine from my attic antenna.
But I shouted into the mic. ;)
pliant garnet
Would that situation be avoided if your mic gain was turned up?
restive fjord
(from Connecticut in the USA)
I was trying to squeeze all the power out of the radio.
It worked.
I'm surprised the guy didn't ask me to stop shouting . ;)
I saw his setup online -- 100 foot tower on the beach.
He was a big DX station with a very good receiving setup.
I worked him at the end of a pile-up of many stations.
12 meters is a neat band and it's new (to me anyway).
pliant garnet
But the propagation isn't doing very well at the moment.
restive fjord
Yeah this was a while ago.
Maybe 9 years ago?
I had a pile of radios I got rid of but I still think I have that one.
restive fjord
Propagation was very good.
Just before the last peak of the sunspot cycle iirc.
I worked all over Europe on a 25 foot elevated indoor dipole in the attic (Buddipole).
With 12 watts SSB. ;)
Normally you want about a hundred watts for that.
pliant garnet
Some people even do QRP and they get contacts from all over, that's insane.
restive fjord
I like QRP. Less is more.
pliant garnet
You are right.
restive fjord
When I used to work the neighboring CB stations I'd lower my power to about 1/8 of a watt or so. ;)
restive fjord
For the two mile or so span I was trying to cover, yeah, they had to look at their S-Meter to notice how low my power was.
You could tell because a third station would ask the other guy 'who are you talking to?' where I could hear the station asking that question, just fine. ;)
pliant garnet
Haha, that's amazing what you can do with that power.
restive fjord
In AM it's in the modulation. You want to see a decent kick on the end of the power range, from when you key the radio to when you speak (kind of loudly) into the microphone.
The needle should jump about 1/3 of an S unit (on a multi-scaled meter).
(On voice peaks).
It's a bit bigger percentage of the power at QRP.
So it sounds really loud on the receiving end.
I was probably about 70 percent modulation.
(50 percent is standard)
But .. at 1/8 watt. ;)
Maybe it was half a watt -- wasn't much on my SWR/power meter.
as low as I could get it and still be about to hit about 2.5 watts when I needed it.
2.5 watts and 4.0 watts are about half an S-Unit apart at three miles.
(wild guess estimates, those)
The old CB standard was 5 watts but the FCC dropped it to 4W at some point (probably near the time when synthesized PLL rigs first became commonly available).
I ran 75 watts (2x 6146-b's in the final amp) in 1974, on CW (morse code).
pliant garnet
What do you mean by 'kick'?
restive fjord
Well it's very punchy the way the needle flicks on voice peaks.
pliant garnet
Right.
restive fjord
If it was a receiver with a good 'window wiper arm' style meter movement, it'd be about half an S-Unit.
(which is less than any two hours apart on a 12-hour clock face)
3-4 minutes on a 60 minute clock face
that's a lot of modulation.
pliant garnet
Oh, so it is based on that needle?
restive fjord
Well I'm thinking of a 5 watt power meter on the transmission line.
pliant garnet
Ok.
restive fjord
The needle would rise on the left, from 9:00 to about .. oh not even 10:00.
The kick would be above the 10:00 part.
Weak AM modulation, the needle 'wiggles' in place about a needle's width or maybe twice that
pliant garnet
I would need to see this for myself. Does this only exist on older radios?
restive fjord
Well they're magnetic (d'arsonval) meter movements with the classic window-wiper style swing.
The other kind is curved out into the room.
These are curved the same way a window wiper is.
I think we call these a 'ribbon' style meter movement:
https://i.ebayimg.com/images/g/jE0AAOSw~CRTqEAF/s-l300.jpg
This is the windshield wiper style:
https://www.adafruit.com/product/252
pliant garnet
Ohh.
restive fjord
(which, to me, is a 'proper' meter and all others need further explanation, but this one is what 'meter' means in electronics, to me)
The good ones had mirrors in an arc under the needle.
for parallax
I've probably owned a hundred of them in a very wide variety of sizes and construction.
My first meter was sealed and made for the Navy. ;)
pliant garnet
Very cool.
restive fjord
Had like 1/4" x 20 threaded studs on the back. ;)
Or lugs (I can't remember which)
pliant garnet
But does the type and kind of meter play a big part in your range and the AM modulation really?
restive fjord
That one's a beauty. ;)
The meter is there to inform the human.
It's not part of the equipment that does the loud talking.
It's instrumentation.
pliant garnet
That meter really looks good if it's on a radio for sure.
restive fjord
People also use an oscilloscope for the same purpose.
pliant garnet
Yeah.
restive fjord
That meter is probably two inches behind the front face, all metal and sealed.
That's fairly representative of the first meters I got my hands on.
Somebody donated a lot of them, still sealed in their military packaging, to our high school electronics department.
(1974)
There was a refrigerator-sized radio something that was there the whole time I was there; I never did figure out just what it was for. ;)
It was about 3 feet tall, almost that wide, and about the same depth as it was wide.
pliant garnet
Nice! But that will be way too big for my liking.
restive fjord
We used it to set other radios we understood on top of it. We used it as a kind of table top. ;)
pliant garnet
Oh, well I guess it can work.
restive fjord
They probably gifted it a long time ago just to be rid of it.
BTW at the time we had some gadget the size of a large oscilloscope that had the one job of converting an existing kind of transmitter, over to SSB. (probably double - sideband or both).
Heathkit designed it.
pliant garnet
Oh.
restive fjord
pliant garnet
With that size, it is amazing how things have changed over years.
Now it is mostly all built into the radio itself.
restive fjord
The critical audio phase shift network is supplied completely preassembled and wired in a sealed plug-in unit.
Well miniaturization came as a result of the arms race. Missiles, basically.
RF excitation from the transmitter is required for the adapter to provide an SSB signal which is then fed to the transmitter final for amplification.
So it had a coaxial cable from the transmitter and another one back to the transmitter. ;)
(both carrying RF!)
(SB-10)
I never touched it as I wasn't licensed for that.
The one guy who used it knew how to. He later became a broadcast radio engineer.
(high school ham radio club station)
pliant garnet
I'm planning to get my amateur radio license so I may be able to get my hands on something like that soon.
restive fjord
Just go to most ham flea markets in summertime -- they have VEC's (Examiners) that are volunteers.
You can take the test cold (it's free or very low cost).
In 1974 you had to know a thing or two to get a license, and sit in front of a real FCC Examiner. ;)
I think I got my Novice at W1AW and took the General in front of the FCC examiner.
The hard part was the Morse code, not being nervous to make a mistake.
I think they just wanted to see that you'd made a real effort to learn it.
pliant garnet
I am actually not located in the US, I'm in Malaysia.
So it is different here slightly.
restive fjord
Ah yeah that would be different.
pliant garnet
There are only two license classes: Class B and Class A.
restive fjord
The ITU covers what everyone can do on radio, in every country.
pliant garnet
Class B basically gives access to most of the bands, but you just can't do CW.
restive fjord
In the USA (where I'm from and am at presently) they allow CW on all the bands (or used to!)
I don't remember if you had to have a special license to use CW.
When I got my license, a CW-only license was the usual way to begin in amateur radio.
The Novice license was a 5 words per minute CW mastery requirement, and a basic radio theory requirement (Including rules and regulations).
Technician class was also 5 WPM CW requirement. Their written exam was identical to that of the General class license (same radio theory and rules).
The General (standard) license was a 13 WPM CW requirement.
languid phoenix
Part of me wishes there still was a CW requirement for licenses in the US, I've always wanted to learned. Although to be honest, I would have had to studied for a lot more in order to pass.
restive fjord
I think the Advanced was a 13 WPM CW and 'advanced' radio theory.
And Extra I believe was 20 WPM CW requirement, and even more 'advanced' (than Advanced) radio theory.
Amateur Extra was a real difficult exam to pass for the radio theory required.
Darman: I got a 5 WPM CW license first and was (at age 14) scared to death of speaking on the radio.
CW was a lot like these 'chatroom' places online -- there's no human voices (at all) working CW.
Since it was in 'code' my brother in the next bedroom over couldn't even begin to imagine what I was saying on the radio!
languid phoenix
Yeah, I've heard a lot from my elmers about CW back in the day, just don't have the money or apartment to do a good CW setup.
restive fjord
I think we should set up a CW chatroom here. ;) Synthesize it in audio.
languid phoenix
I'd be ok with that, although code blocks would be hard!
restive fjord
(there were always 'cheaters' with computers to decode CW)
(and keyboards to do the sending!)
(go out for a drive in the country and let the robots work the DX, back at the homestead!)
Well what you want is to simulate on the air contacts, not code practice.
CQ CQ CQ DE WA1TNR WA1TNR WA1TNR ... (long pause) K
when you hear that K (you were waiting, it's like a hunt) the pulse quickens.
restive fjord
It was always exciting to hear a distant station, and contact them, only to find out they were a lot further away than you had supposed.
Is that kilo india? fonts are hard to read
languid phoenix
Affirmative, Kilo India
restive fjord
I've never once heard a Kilo India call! Hehe.
KB1XXX is about it for me. No KC1 KD1 nuthing.
Did they skip over a bunch of letters to get to Kilo India?
languid phoenix
I'm younger, Just got my Tech little over a year ago
I don't know if they skipped at all
languid phoenix
I like it, liked my call enough to keep it instead of gonig for a vanity
restive fjord
In my day (when I got on the air for the first time) it was K1TNR or W1TNR or WN1TNR or WA1TNR and there was no other common variant (in 1-land)
languid phoenix
wow
restive fjord
I've had mine too long so I'll only do W1TNR or maybe K1TNR but I don't think I'd do anything else.
My friend Mike had an assigned call he didn't like WA1RYL.
He later became W1OD.
YL meant young lady back then.
languid phoenix
ah
restive fjord
He was fourteen and his voice hadn't changed yet. ;)
languid phoenix
ouch
restive fjord
Yeah so he really didn't like his call.
This guy, later in life, was working CW mobile at about 35 WPM. ;)
languid phoenix
wowzers, that's crazy, I'm lucky some days to type 35 WPM
restive fjord
Hehe I can type 45 WPM but my CW copy is solid at about 10 WPM. 20 WPM for very short stretches.
Copying on a mill was a skill I didn't appreciate at the time. Now it's preferred.
I don't see a reference online for that one. ;)
It really was jargon to the max back then.
Ham stuff was more jargon than I got anywhere else, by far.
languid phoenix
Try some of the guys that are really into online gaming, plenty of jargon there.
😛
restive fjord
Yeah I don't at all like anything about video gaming.
I've seen what it does to people I care a lot about.
When somebody starts in with that I slip out the side exit, quietly.
(20 minutes later they look up and ask where I went)
languid phoenix
My apologies, wasn't trying to get into it.
restive fjord
No please don't misunderstand; I was just sayin'.
languid phoenix
Fair enough 😃
restive fjord
It started with television watching. That was the one thing you could (conveniently) point to and comment about it.
Evil is a hill -- we stand on our own, and speak about others.
Huh: mill:
The concept of a typewriter dates back at least to 1714, when Englishman Henry Mill filed a vaguely-worded patent for "an artificial machine or method for the impressing or transcribing of letters singly or progressively one after another."
I wonder if that's how it got that name for ham radio uses of a typewriter
languid phoenix
huh, cool find!
restive fjord
It was a real hard transition (still fighting it, really) from typewritten documents to proportionally-pitched communications fonts.
I still don't like proportional very much.
The VGA font in a (computer's) video card is a really nice font.
languid phoenix
I guess part of being a digital native is never having thought about the differences in fonts and how different modern computer fonts are compared to older typewriter fonts...
Hmmm
restive fjord
Well it's pretty simple -- monospaced fonts allow you to construct your own aligned columns, using only the space bar and similar keyboarding.
languid phoenix
yeah
I just never thought about anyone having trouble transitioning to proportional fonts is all.
restive fjord
Fruits Vegetables
===== =======
Apples Carrots
Pears Peas
Oranges Okra
So we need a discord server with all text converted to CW audio, and monospaced fonts?
restive fjord
If my input box had monospaced fonts I'd have got that the very first try.
Did you ever see someone post structured computer code in a proportionally pitched font, in a forum?
It looks awful (and worse).
languid phoenix
Agreed, not very fun to read.
restive fjord
An ebook is best in a proportionally pitched font, but only when it's a narrative like a story or a novel.
For plain written communication (story-telling) it looks better than a typewriter.
languid phoenix
I've noticed I like code and more technical writing in mono-spaced now, part of that is probably being exposed to it a lot more in engineering.
restive fjord
Too much CW is why they invented the OFF knob on the radio (early models didn't have this feature).
I find that more diagrams are really what is wanted and that they're expensive (in time at least) to produce. It's so much easier to link a JPEG from a Google image search. ;)
It's very interesting to see the Adafruit communications evolve; what they got right (early on).
Just that they thought to do it, is odd.
languid phoenix
The amount of graphics and diagrams in the Adafruit Learning System is astounding to me. Probably why I recommend Adafruit so much to my college students.
restive fjord
I think they fit a niche that's one level above 'introductory' as in when you browse books in a bookstore and find either the book is too basic/introductory, or really whitepaper ish.
Nothing in between.
languid phoenix
Yeah, although their introductory tutorials are very good as well. I've taught kids how to solder and blink LEDs for the first time using Adafruit tutorials. But you're right, there is a TON of stuff that's above introductory.
restive fjord
Blink is a really big deal.
I'm doing bare-metal programming now and a blink is a very good thing to see.
languid phoenix
Indeed. I taught kids as young as 6 how to do blink with the new Circuit Playground Express. The look on their faces when they realize it's blinking a light pattern that they programmed is very cool.