Category: Ham radio

APRS Testing

This past weekend, the radio’s GPS and APRS got tested out on a road trip to the Chattanooga, TN area.

The GPS works pretty well. Takes a few minutes to lock onto the satellites after turning the radio on, but once it locks it tracks well. The radio displays latitude/longitude, speed, direction and altitude. It’s neat watching my GPS coordinates update while driving down the highway.

APRS worked well, but I’m discovering that at 5 watts of transmitting power, the APRS holes are pretty big. Receiving APRS beacons from other transmitters was pretty easy. Getting my own APRS beacon out and received was harder. With my radio in the car with me on the way out to Chattanooga, it beaconed pretty well in the Charleston area, and again in Columbia, but after that nothing. On the way back to Charleston, I was able to connect my radio to Connie’s mag mount antenna on the trunk of the car. Outside of the big metal cage that is the car, I was able to receive even more APRS beacons from other stations. Getting my own beacons out was also noticeably easier. My radio beaconed a lot more on the way back with the mag mount antenna than it did on the way out. It was still pretty sporadic and the holes were still pretty big, but a definite improvement over trying to transmit through a big metal cage.

Thanks to a stop at Ham Radio Outlet in Atlanta, I now have my own dual band (144/440 MHz) mag mount antenna (an MFJ-1729 mag mount kit) mounted to the trunk of my car. Now I should have a much longer range on the radio when I’m in the car. Help me test it out. I’m usually listening on one of the CARS repeaters. Give me (KK4JRP) a call on the radio!

Accessorizing the radio

My radio has its first accessories: a speaker/mic (MH-74A7A) and the GPS module.

The first thing that struck me about both the speaker/mic and the GPS unit was how small they were. Quite a bit smaller than what I expected from a hand mic (something big and chunky). The MH-74A7A is the size of my palm and at first seems like it would be too small to hold or use comfortably. Turns out to be not so bad though, and the lighter weight (compared to holding the radio) will probably mean less fatigue when playing radio. I think the cord weighs more than the microphone itself. There’s a single PTT button on the side and that’s it, so using it is pretty simple.

Sound quality is pretty much the same as what I get out of the radio speaker, although perhaps not quite as loud. No complaints there. The nice thing is that I can clip it closer to my ear for easier listening, rather than walking around holding a radio up to my head. Stick the radio in the side pouch of my backpack, clip the speaker/mic to the shoulder strap and i can walk around listening to the weather radio or for any radio activity. Much easier than walking around holding the radio up to my ear or in front of me.

The GPS module is even smaller than the speaker/mic (about half the size) and plugs right into the top of the speaker/mic and secured by a screw. So far it seems to work pretty well and gives the radio GPS capabilities and makes the radio’s APRS feature useful. It’s small and light enough that it doesn’t make the speaker/mic top-heavy when it’s attached and secured into place.

Overall, the combination is nicer and much easier to use than I expected it would be at first glance. Used it a few times now to play radio and so far the most awkward part is getting tangled up in the cable. I think I’m going to enjoy using the speaker/mic with my radio.

Thoughts on HamCamp

Just a few thoughts as I continue to ruminate on the idea.

The idea of the HamCamp is to start with a mini-camp within BarCampCHS. Sessions and presentations should be short (maybe 15-20 minutes) so that a few can be fit into each BarCampCHS block. They can be introductory for new hams/wannabes or cover more advanced topics

  • Good radio conduct
  • Antenna anatomy
  • Assembling a ham shack
  • Licensing/regulations
  • Radio bands
  • Digital radio modes
  • CW (Morse code)
  • Echolink/Winlink/IRLP
  • Contesting

There can be outdoor sessions and demonstrations which obviously won’t be constrained by BarCampCHS scheduling.

  • Radio demonstrations
  • Antenna building

HamCamp

With BarCamp Charleston getting closer, the idea popped into my head about doing something similar with ham radio, a Charleston HamCamp.

Ham radio has a strong tradition of mentoring, or “Elmering” in ham-speak. Having an event like HamCamp seems like it would be a great way to foster more Elmer-like activities. It’s an idea that’s been kicking around in my head for all of a couple hours now, so not entirely fully formed yet.

It would follow the BarCamp concept, so people could come and provide talks, demonstrations, tutorials and share other ham radio related information and ideas. There will be some space to set up portable radios, something outdoor to show off things like antennas and get some radio activity going.

Maybe it can start off as a mini-camp at BarCamp Charleston…

Learning about digital ham radio

Yesterday was one of ARRL‘s Rookie Roundup contests, so some of the CARS members organized a rookie radio day to show off some of the digital amateur radio modes.

The idea is pretty simple. Instead of piping the audio output of the radio signal to speakers, it’s sent to a computer (with some intervening hardware) where the digital signals are decoded and displayed by software. The computer’s sound card generates audio tones that are sent to the radio for broadcasting and for other computers to decode. Everything is handled through the computer and software (fldigi in this case) using pre-programmed F-key macros (manual typing works too) except for changing radio frequencies (with the right set-up, even that can be done on the computer). Pretty neat stuff.

There were three of us rookies around and we all got to play digital RTTY (radio teletype) radio, sending out calls, responding to other operators and learning how to use the software. I think we made a total of 6 contacts, which isn’t huge but there might have been some power and/or antenna problems. It was still a good learning experience.

Another member set up a battery powered radio with a 40m dipole antenna and demonstrated sending emails over the radio via Winlink, another pretty cool amateur radio service. Find a reachable Winlink server to broadcast to, compose your message and the software sends the appropriate signals to the radio (via intervening modem) to the listening server, which in turn sends out the emails over the Internet. You can also download any received emails stored up for you. Using this method, even if you’re out of power, have no other form of internet access, or are in some other kind of emergency communication mode, you can still send out emails to other people as long as you can reach a server with your radio. Pretty awesome stuff. The data rate is pretty slow, but you can still get communications out.

It was a fun three hours we spent playing radio, and a good introduction to digital radio. Makes me want to do more