[amsat-bb] Re: Explorer I - recordings

Roy rdwelch at swbell.net
Tue Feb 5 14:37:24 PST 2008

Hi Phil,
Gosh it's been a long time since I last saw/heard you.  I can't recall, 
but I think initially you were still with Ma Bell weren't you?  I've 
been retired since 1991.

In answer to your question, I don't think any of my recordings showed 
such a counter stoppage.  If it did, I wasn't recording at the time.  
The receiving setup was not very good for extended periods of tracking 
what with a fixed antenna.  I just found the old Life Magazine article 
about that launch.  I must have tucked it away in the bottom of the 
trunk and forgotten about it.


Phil Karn wrote:
> Roy wrote:
>> 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.
> Explorer 1 may not have been the first satellite in space, but it was the first
> to make a significant scientific discovery -- the Van Allen belts. That particle
> detector stopped reading above about 2,000 miles because it was saturated by the
> extremely high count.
> I wonder if any of these recordings show that happening.


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