[A-DX] (dxld) 60 years in space today!

Mi Okt 4 20:45:51 CEST 2017

Am 04.10.2017 um 16:33 schrieb Mike Terry  [dxld]:
> In October 1957, amateur radio operators monitored the first signal 
> from a spacefaring civilization —— and it was us.
> Sputnik 1, the first satellite to orbit the Earth, launched on Oct. 4 
> of that year from a site in Kazakhstan, then a part of the USSR. That 
> site is now the Baikonur Cosmodrome; at the time it was site 1/5 at 
> the Tyuratam range.
> Article here:
> Sputnik's Beeping Legacy: Satellite's Simplicity Made It Iconic 60 
> Years Ago 
> <https://www.space.com/38357-sputnik-launch-60th-anniversary-space-age.html?utm_source=notification>



".......The meaning of the D-200 designation is unclear and our research 
thus far has failed to produce a schematic of this transmitter, but 
Tikhonravov, in a presentation before the 24th International 
Astronautical Congress in 1973, characterized the transmitters as 
“vacuum valve-type” with a power of 1 watt...."

".....One transmitter operated on a frequency of 20.005 MHz and the 
other on 40.002 MHz. The choice of these frequencies not only allowed 
reception by amateurs using existing equipment but also enabled a 
receiver set at exactly 20 or 40 MHz to produce an audio tone plus or 
minus the Doppler shift without ever going through zero Hz. This insured 
that the telemetry was audible throughout an entire pass without 
additional tuning of the receiver.

"..... WWV’s Role

Radio Station WWV also played a role in early space flight. There are 
numerous recollections among ham operators who were active in 1957 that 
radio station WWV suspended its 20 MHz time signal transmissions during 
some night-time passes of the satellite in order to avoid interference 
with the 20.005 MHz telemetry signal. Roy Welch, W0SL (then W5SLL) 
recalls this to be the case on October 7 when he recorded the Sputnik I 
signal during a pass over the North America. This recording can be heard 
at the AMSAT link listed at the end of this article.

An exact record of how many times and for how long the WWV may have 
turned off its 20 MHz broadcast while Sputnik I was in orbit has been 
difficult to document. According to Michael Lombardi, KB0VOI, a time and 
frequency metrologist at the National Institute of Standards and 
Technology and a WWV historian, the log books for WWV operations during 
1957 no longer exist making it difficult to verify that the 20 MHz 
broadcasts were stopped. However, Lombardi notes that during the Sputnik 
era, the WWV schedule included a silent period during which 
transmissions were interrupted every hour for approximately four 
minutes. These periods began about 45 minutes past the hour. Also 
well-documented is that during many passes, the WWV signal remained on 
and was recorded in tandem with the Sputnik telemetry beacon. This 
provided a stable time reference from which the Doppler shift of the 
satellite’s signal and its orbital parameters could be calculated. ...."


"Play the Sputnik Audio Clip and Hear the Doppler Shift!
This audio clip is about 94 seconds long with a pronounced downward 
change in pitch at 47 seconds demonstrating the "Doppler Shift" that 
occurs just as it passed over.  Make sure to be watching a clock with a 
"second hand" as you listen! ...."


Based on this 60 year old audio recording I detected  a Doppler-Sfift of 
about 60 Hz.  In a wave editor you can see the cycle of about 2 beeps 
per second.

So in STUDIO1 the 20,005 MHz signal would have been seen - in 1957.

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