Amateur and other Radio Communications

I thought I’d start a thread for discussing radio-specific topics in, so we don’t clutter other threads with those digressions. This is a placeholder for now, but you’re all welcome to join me in starting to propagate the seeds of these chats here! Anybody interested in trying SDR? Anybody who has installed and operated their own repeater? I’ve done a fair bit of mobile and offshore ham and maritime radio work and would like to get into QRP, personally.

I’ve kinda slacked off practicing with the HAM gear, I need to get back to it. I’ve enjoyed mostly digital, PSK31, RTTY, Olivia, etc. Still learning how a lot of it works, but I find it very interesting the different ways data is encoded and decoded to deal with low power, noise, and so on. I chatted with a net a few times with RTTY, and it took nearly 400 watts to be heard in Victoria, BC. Everybody decided to try Olivia for a while, and in the same conditions we could talk to each other with just under 100 watts.

I find APRS quite fascinating. Enough that it got me to start reading the spec sheet for the whole standard. It’s accessible enough for a newbie like me it’s helped me understand a lot about packets and communications as a whole. Now I understand at least the basics of packet frames, bit stuffing, clock recovery, and so on.

Also it’s driven my interest in the low bandwidth, decentralized communications like we discuss here. In the golden days of Ax.25, BBS and APRS the repeater networks could send a message almost anywhere up and down both coasts. HAMs had text messaging before cell phones existed, how cool is that!

My next milestone in radio to work towards is CW. I’ve been trying out a program called ALDO, which uses the Koch method for training morse code. I can now reliably decode about 6 letters… yeah, still a ways to go yet.

turns his radio on

I just have a UV-5R+ for my VHF work, and I’ve been bad at actually bothering to turn it on when I’m in my office. I can hit a few local repeaters with my external antenna, but the bulk of the close ones are digital, and I don’t have the gear for that. Unless I go full on SDR (and have enough TX power). I’ve got plenty of SDRs, I’ve just not made use of them. Including, somewhere, a HackRF One which can transmit on most bands.

I’ve considered putting a small antenna farm on top of my office to snorf things like airband comms and ADS-B, but I’ve not actually done that yet.

All I have is a hackrf and some cheapo baofeng VHF/UHF units at handhend wattages.

SDRs are nifty. Not really interested in the neckbeardy parts of ham, though. So most of the fun is in the higher ranges and ISM bands, especially the license free ones.

I had been on the ham sidelines for years (lost my license) until my son got to an age where I thought ham radio would be interesting for him to use on scout camp outs, so I took him with me when I tested to get my license back. Thought that would inspire him, but he never got interested. Me, however, seem to have a radio acquisition problem (2 HF rigs and 4 HTs). I get on the air mostly for FT8 digital mode, but just this weekend was trying our DStar. That was pretty neat to hear guys from Australia talking to guys from London on 70cm. I recommend the pi-star.

I really need to get myself some HF gear and set up antennas. The longer range stuff sounds far more interesting than local VHF work.

For those of us with antennas much, much lower than one wavelength above the ground, even a simple dipole is pretty much an NVIS antenna.

I mention it because it also has a good chance of making for better local comms, for those of us in hilly territory.

I know I need a kick in the pants to get on learning CW for real, maybe someday we can get a CW practice net going or something.

CW over Matrix! I bet we could…

We’d have to stay unencyrpted though.

That’s fine. Just as practice.

Actually you wouldn’t need to through Matrix, the FCC only says it’s the OVER THE AIR part that cannot be encrypted. Doesn’t say it can’t hit other media tunnels and be encrypted there.

Who’d want to encrypt their CW anyway? and how? by hand with a Caesar cipher?

And yeah, it’s amateur radio bands where encryption is forbidden, not the protocol itself.

Wait, you don’t encrypt your CW? I double ROT13 everything I care about, use quad ROT13 for higher security applications! DMCA violation to decrypt me! :smiley:

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It’s interesting, though… you can use proprietary encoding methods which are indistinguishable from encryption (PACTOR-4 is ridiculous, for instance) - so long as they are theoretically decodable by anybody listening. For all intents and purposes, though, unless you’re the PACTOR company or a governmental agency, you’ll not be able to make any use of a PACTOR-4 data transmission you listen in on at all.

That said, I’ve used PACTOR-4 on HF and the throughput is genuinely stunning.

I’ve wondered about PACTOR. Encoding methods are supposed to be ‘open and available’ and that makes it ‘not encryption’. So you and I can come up with a new digital mode to play with, and as long as it’s posted somewhere it’s legal even if you and I happen to be the only two people using it.

But PACTOR? It’s not open, and you have to buy their hardware to decode it. How does that follow the FCC rules?

I think I read somewhere that one of the early variants (Pactor-II?) is “open” for some values thereof, and thus usable on ham channels, and it may well be that Pactor-IV is only permissible on the maritime bands I was authorized to transmit on for ship-shore radio telecommunications. I don’t remember seeing many significant warnings to that effect from PACTOR though.

Same way that d-star is allowed on ham bands, I guess.