[amsat-bb] Explorer I - recordings
rdwelch at swbell.net
Thu Jan 31 12:53:55 PST 2008
I have been asked if any of the Explorer I recordings were still
available in WAV, etc format. There is one posted at
http://www.amsat.org/amsat-new/index.php. Select the "Select a Topic"
drop down menu and scroll down to "Sounds from the first satellites."
There are a few recordings there with the info about the recordings.
One of them is the Explorer I telemetry. You will hear several constant
audio tones with one of them shifting between two tones. There was a
geiger counter on board that counted cosmic ray particles according to
the info I have read. After a certain number had been counted the tone
shifted and after another quantity had been counted it shifted back again.
The 108 mHz antenna was a six element colinear arrangement consisting of
six half waves (wire elements) suspended over a 13x13 ft wooden frame
covered with chicken wire laying on the roof of my house. This oriented
it up about 75-80 degrees above the southern horizon. No tracking. The
satellites had to fly through the main lobe of the antenna pattern.
The receiving arrangement was a modified TeCraft (I think) converter
with a 6BQ7 TV RF amplifier front end feeding an National NC-300 Amateur
band receiver. Not very good as noise figures go today but pretty good
I still have all of the original reel to reel tapes, some of their
contents transferred to cassette tape.
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