The domain name for this site is my ham radio callsign; I got my Amateur Extra license in 2016... and haven't done much with it. Since this is preparedness month and most of my attention has been turned to getting ready for whatever contingency comes up (there's a couple on my radar), I figured I should start getting back up to speed on radios.
Talking on VHF and UHF is fun and easy, but I'd like to be able to get up and running on some digital modes. The first is APRS, which should be relatively easy to do. I've got all the softwares installed on my laptop, and I've got an FT-817 and Signalink, so let's get working. I started out with the Signalink volume knobs set halfway and the delay turned all the way down. I also set up a few menu settings on the radio:
- Menu 07: set to front
- Menu 39: PKT Mic set to 75
- Menu 40: PKT Rate 1200 baud
- Menu 45: SQL/RF-G Set to RF-GAIN
- Menu 51: VOX Gain set to 1
- Menu 52: Extended menu options set to ON
On the FT-817, press and hold F for two seconds to enter config, then hold it down to save settings.
I've been reading around a lot and these two blog posts seem to be useful:
- Demonstrating Amateur Radio Digital Modes with simple VHF/UHF Digital Stations (Part 1)
- Demonstrating Amateur Radio Digital Modes with simple VHF/UHF Digital Stations (Part 2)
The first step is to fill out a configuration for Direwolf. I used arecord -l to figure out that the Signalink is the second sound card (or plughw:1,0). Then, template out this:
ADEVICE plughw:1,0 ACHANNELS 1( CHANNEL 0 MYCALL YOUR-CALL MODEM 1200 AGWPORT 8000 KISSPORT 8001 DWAIT 50 PBEACON delay=00:15 every=30 overlay=S symbol="digi" lat=XX.XXXN long=YYY.YYYW power=5 height=200 gain=3 comment="CITY ST" via=WIDE1-1,WIDE2-1
You can figure out the lat/lon stuff with GridMapper.
The Signalink uses VOX for PTT, so no need to configure that. You can run Direwolf now, and should see something like this:
~ (0) <heidrun:kyle> $ direwolf Dire Wolf version 1.5 Includes optional support for: gpsd hamlib Reading config file direwolf.conf Audio device for both receive and transmit: plughw:1,0 (channel 0) Channel 0: 1200 baud, AFSK 1200 & 2200 Hz, E+, 44100 sample rate. Note: PTT not configured for channel 0. (Ignore this if using VOX.) Ready to accept AGW client application 0 on port 8000 ... Ready to accept KISS TCP client application 0 on port 8001 ... Digipeater WIDE2 (probably BKELEY) audio level = 2(1/1) [SINGLE] ____:____ [0.4] KJ6DZB-3>APAVT5,WA6TOW-2,WIDE1,BKELEY,WIDE2*:=3752.66N/12217.83W>029/000/A=000019144.390MHz 3.59V 75.2F "144.390" in comment looks like a frequency in non-standard format. For most systems to recognize it, use exactly this form "144.390MHz" at beginning of comment. Position, normal car (side view), SainSonic AP510 which is a 1watt tracker N 37 52.6600, W 122 17.8300, 0 MPH, course 29, alt 19 ft, 144.390 MHz 144.390MHz 3.59V 75.2F
So it's working, and it's time to fire up Xastir.
Xastir, in the tradition of ham radio software, has a rather unfortunate interface. You'll want to make sure to configure your callsign and locator and all that.
Next, go to Interface -> Interface Control -> Add. Direwolf works as a Networked AGWPE, so select that; the defaults should be right. You can check the port against what Direwolf reported:
Ready to accept AGW client application 0 on port 8000 ...
I set up my Yaesu VX-6R to listen in; I could hear digital transmissions come through and I knew to check the console to verify that I was decoding stuff. I also set up a Baofeng BF-F8HP with a BTECH APRS K-1 cable on a second laptop with Direwolf in another room running to check transmissions.
Set up your radio to the correct frequency (e.g. 144.390MHz). Here's where I started to run into problems. The FT-817 defaulted to FM mode, and that worked fine for receiving APRS packets. It wouldn't trigger the PTT when I tried to transmit, though. If I set it to PKT mode (you're supposed to use PKT for non-HF, I've heard), it would often not receive. I fiddled around with the levels on the Signalink and the RF gain settings, eventually they started coming through.
The second problem was my transmit levels:
AI6UA audio level = 0(0/0) [NONE] :|_______ AI6UA-7 audio level = 3(1/1) [NONE] |||||||__
My radio isn't transmitting loudly enough, it looks like. The numbers above refer to roughly how loud the signal is; you want the first number to be as close to 50 as possible. The numbers in slashes are a ration of tones, you want them to be as close as possible. The more vertical bars, the better.
A bunch of digging around and I finally sorted it out:
AI6UA-7 audio level = 45(8/13) [NONE] :|||_____
The issue? Somehow menu setting 40 PKT Rate had been set to 9600, not 1200. Fixing that and all was well.
Not sure if anyone is receiving, but there's that.
Next up: RTTY over VHF/UHF.
Uh, that was easier than I thought. I ran into problems earlier trying to follow along with that digital mode part 1 blog, and it wasn't working. I already know that my BTECH APRS cable doesn't work with my laptop's soundcard (e.g. it won't trigger PTT), so in order to transmit with the Baofeng, I have to hold down the PTT and hit transmit.
The long story short: set up fldigi with your radio; I have a CAT cable and I use the Signalink with my FT-817. Set the operating mode to PSK->BPSK31 and send away.
I need to explore some other digital modes and figure out how to compact the setup.
The real next step I guess is playing with js8call.