The satellite images are received at VK3UKF via a turnstile or crossed dipole antenna cut for a center frequency of 137.5 MHz. The highly technical satellite antenna mount consists of two borrowed milk crates which were just perfect to make the roughly 30 inches the antenna should be from its reflector, sitting on a length of wooden dowel across a wire mesh bed base, propped at an angle facing North on the carport roof. Oh and uh, with wings of the back of an old washer attatched for a bit more bounce.
The turnstile antenna is tied to the crates and an RG-58 coax feeds the pre-amp sitting under the metal covering in the background. A line of RG-213 then carries the signal inside to the APT receiver.
The pre-amp sits up near the antenna and to operate, is fed with 13.8 volts, which comes up the coax from the APT receiver.
The 13.8 volts comes from the power supply and is filtered before going up the coax to the pre-amplifier. Note the small coax carrying the received signal to the radio receiver circuits from the antenna socket has a tiny chip capacitor soldered between it and the center pin of the connector socket, this prevents the 13.8 volts d.c. going into the receiver circuits.
The APT receiver has a small dedicated power supply. Full details of how to do this will eventually see their way to the net.
The APT here is a converted Philips FM 828. This magnificent operation was carried out by a chap named Chris in a place we all know as darkest Carrisbrook, Chris can fix most things with as little as a piece of curly wire.
After having most of its inards removed, a new oscillator with its own power supply volt reg, glass tube trimmer cap, and a pot for the frequency adjustment was constructed. The FM 828 has two crystal filters in it, one is wide band and one is narrow, the big one with lots of crystals in it is the narrow band filter. Take it out and put it in the spares box. replace it with another wide band filter. This will enable you to receive the full satellite signal and process it to your ability.
The software I use is WinOrbit to track the sats I am interested in. I use WxSat to initially record the telemetry from the APT receiver onto the computers hard drive as a wave file, average full pass wave file uses about 8-12 MB. I then use David Taylor's Satsignal Program to make the images in visible, I.R. light and display cloudtop images and thermal readings displays.
