Current Radio Projects

2007-12-15 16:44:00+00 

In response to Steve (MM3ZXL)'s post on cpsarc.com; "What specialisations do various members have? "

Generally speaking, I specialise in QRP and construction. You'll have seen pictures of shacks on the site, usually perfectly tidy and perfectly set up for operating -- I'm afraid I have to reach behind piles of components to reach the power switch!

The last thing I finished building was a TiniCat sound card interface for my FT-817. (Hence the post about PSK-31.) I have a couple of 70cm pre-amplifiers sat on the desk awaiting being built -- one Vectronics kit, and one of my own design. I also have a half finished valve amplifier sat in a corner.

The current project on the Bear's Bench is half a turnstile over reflector antenna. This is a (mostly) circularly polarised antenna that I'm planning on using for satellite operations. The most likely targets are AO-51 and AO-27 which both downlink on 70cms (435MHz).

During the summer, Tor (MM0PID) discovered that we were allowed to poke satellites, and poked me until I figured out how... After a certain amount of pondering and acquiring tracking software, it turned out that there was a good pass of AO-27 in a few minutes time, so I cobbled together a "ground station" using the FT-817, the dual-band aerial off the car, and some random coax patch cables I had lying about and went out into the garden at the appointed time. The "wave the whip antenna about" method worked a lot better than I would have expected, and I got some solid copy from the bird. However, with a QRP rig and little gain on the antenna I was never going to be able to capture the repeater, so it was just one-way. With the winter upon us, I'm not so fond of standing about in the garden, so it's time to build something that I can work from inside the house! The turnstile antenna looked like the easiest way to start -- the 70cm version allows me to start with one, adding the 2m uplink later.