SAT-TRACK GOES WIRE-LESS





My satellite tracking, antenna system is very basic.
A handheld 7 element yagi, which by listening to recovered audio in headphones,
is manouvered to maintain the best signal strength.
From a satellite pass prediction: I obtain the estimated time and compass bearing (azimuth)
of rising (AOS) and setting (LOS) of the satellite.
AOS: acquisition of satellite, LOS: loss of satellite
Maximum elevation and time thereof is also given.



Previously; there was always a trailing antenna and/or audio cable(s)
which you had to avoid whilst slewing the antenna to follow an overhead satellite pass.
The lastest changes allow me to track a satellite pass, "wire-less'ly"
The RF section consists of the yagi with boom mounted handheld UV-5 xcvr (tuned to satellite frequency)
Minimal aerial coax run, means reduced signal loss.
Audio O/P from xcvr jack is fed to headphones with a small 1:1 audio coupling transformer in the "earthy" end.
Tfmr O/P modulates a tiny FM transmitter size: 2cm x 1cm
powered by a single 3 V CR2032 lithium button cell.
I adjusted tuning to 86MHz.
I had to unsolder the on-board electret mic' and AC couple the received audio
This transmits the signal to a communications receiver inside my radio shack.
The receiver is patched to PC soundcard input, which is running decode software.
I am using all OTS (off the shelf) componentry.

ISS data decodes received 145.825MHz (click to enlarge) ISS SSTV transmissions 145.800MHz (click to enlarge)