----- Original Message ----- From: "Robert Bruninga" bruninga@usna.edu To: amsat-bb@amsat.org Cc: GilMoore12@aol.com Sent: Thursday, December 20, 2007 2:26 AM Subject: [amsat-bb] Vanguard 1 Reception?
Anyone with an EME dish that can mount a 108 MHz feed?
Rumor has it that Vanguard 1 should still be emitting a tiny singal on 108.00 MHz since it was directly powered by solar cells. It has gotten weaker and weaker over the last 50 years using the 1957 solar cell technology, but what the heck. It would be a nice challenge for someone with a really big dish..
Just thought I'd post, since I had not heard of this frequency and the fact that it is radiating.. You just have to have good ears. And with some of the really good sound-card DSP stuff these days, maybe it would show up on a waterfall. The exact frequency depends on temperature... But it was at 108.00 MHz last time it was heard.
My dish is kaput right now, so I'm out... Bob, WB4APR
Hi Bob, WB4APR
Early 1957 the frequency 108 MHz was used for space to ground communications and in august 1960 I was receiving the 50 mW beacon from ECHO-1 at 108.000 and 108.030 MHz
At that time 108 MHz was free of any commercial communication and the galactic noise was received with easy using only a 5 element yagi and a downconverter with a cascode front-end made of two low noise triodes 6AN4 at best a 5 dB noise figure.
Very soon 108 MHz was abandoned and space to ground communications switched to 136 MHz
Actually the lower edge of 108 MHz is used for commercial and FM broadcasting and try to receive a weak signal less than 5 mW from Vanguard-1 requires an EME dish in a properly selected location.
73" de
i8CVS Domenico