70cm Yagi Antenna for Satellite Work

The 70cm Yagi – $18 (minus coax/connector)

Used for the SO-50 and AO-27 satsA local contact that I made on the ISS, KF4GTA, suggested that I try out working some FM “birds” when he checked into the Colquitt County Ham Radio Society’s friendly net this week. He mentioned SO-50 and AO-27, and so far I’ve worked the SO-50. At first I didn’t think that I had the right equipment, but then I remembered that my FT-60 was a dual band transceiver that did both 2m and 70cm. Shortly after that realization I was working towards working the birds.

First, I downloaded HamSatDroid on my Samsung Tab and my Motorola Razr. I then added my position and updated the Keps. I noticed there was an AO-50 pass around 10:30pm EST so I started preparing.

Second, I grabbed my FT-60 and my Arrow 146-4 (which is not optimal for 70cm, but it would work in a pinch). I connected that to my radio and then I added the satellite frequencies to it.

Third, I then had to re-enter the frequencies because I knew I needed to adjust for Doppler. I’ve never really had much interaction with Mr. Doppler except for the occasional ambulance, so I was pleased to see how well the Doppler effect worked on a 70cm signal. I have the downlink ranging from 436.805 to 736.785.

I made my first contact using the Arrow 2m antenna, but I instantly forgot the call sign. I also had a very weak audio from the downlink so that is when I started thinking about building a small directional antenna. The parts that I gathered were: Continue reading

Packet Radio Using Remote Control Through SSH Server

Recently I have been messing with APRS and other packet radio transmissions, and I haven’t really found it to be all that enjoyable in its present form. Don’t get me wrong. I have had plenty of fun with it, but it hasn’t been what I want to do. My previous articles about getting Xastir up and running and sending packets through the ISS show that I enjoyed what I was doing, but the problem is that neither situations were very convenient. With APRS, I had to start up a laptop and initialize the TNC or I had to keep it running and risk killing the car battery. With the ISS I had to be ready to go at a moment’s notice, and since many of the passes were during work hours, I was not able to leave and drive to the clearing to make contact. Now, I think I’ve come up with a solution. Continue reading

Xastir and my KAM TNC (Went with KISS mode)

I found something to occupy my time the last couple of days. I got tired of typing my own APRS positions into a document and sending raw packets to report my position (@240805/3108.03N/08343.16W>000/000/Robbie kk4fgm.com…). Every time I came to a stop at a parking lot and before I exited the vehicle, I took a look at the GPS and the clock and typed the information into a document. Then I sent the raw data in GtkTerm to the TNC. It made my wife mad to have to wait the three to five minutes once we arrived at a destination. Frankly, it made me even more mad because I had to wait for the GPS, open a terminal and VIM a file, then type in the commands to the TNC. I knew that I was going to have to find an automatic program to do this for me. That program is Xastir.
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