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Tuesday, June 7, 2011

Searching for the Sputnik Schematic

Mike, AA1TJ, has launched (!) yet another intriguing project. See below. In an effort to come up with the actual Sputnik schematic, I have thrown down the geek gauntlet to our fellow nerds at sci.space.history:

Greetings Space Historians!
We are a group of radio amateurs and we probably rival you in our
technical geeky-ness. We are now involved in an effort to re-create
and put on the airwaves replicas of the 20 MHz transmitters used in
Sputnik 1. (We will use the amateur radio 21 MHz band).
We are trying to find a schematic diagram for the transmitter. Can
you help us? Thanks.


Arnie, CO2KK, told me last night that as a 15 year-old boy he'd made
it into the newspaper by picking up Sputnik's signal on his Hammarland
Super-Pro receiver.

Don Mitchell - a physicist now retired from the Bell Labs - also wrote
last evening to ask if I knew of a schematic diagram for the two
transmitters used on Sputnik-1. Mr. Mitchell maintains an informative
web site on the topic of Sputnik. Here, for example, is the link to
his page on the first of the series of "Travellers" to be lofted into
orbit in late 1957 into 1958.


To the best of my knowledge the schematic for what may be the most
famous QRPp transmitter has never been published. It's a shame,
particularly as it would have been great fun to build an approximate
replica for use on the ham bands

However, I woke up this morning wondering why should we allow the lack
of an original schematic to stop us when there's plenty of descriptive
evidence available? "Spaceflight Magazine," for example, published a
wonderful article on the 50th anniversary of Sputnik. The story was
pieced together from original documents over a period of 20 years. You
may read the article here


"The two D-200 type radio transmitters operated on frequencies of
20.005 and 40.003 megacycles at wavelengths of 15 and 7.5 m. These
transmitters (which obviously used vacuum tubes) each had a power
intake of 1 watt and provided the famous “beep-beep-beep” sound to
Sputnik. The signals on both the frequencies were spurts lasting 0.2
to 0.6 seconds, and carried information on the pressure and
temperature inside the satellite; one set would transmit during the
“pauses” of the other."

"Despite objections from just about everyone, Gringauz insisted that
PS-1 carry a high frequency transmitter (the 20.005 MHz transmitter
operating in the decameter waveband) in addition to the VHF
transmitter (which had been commonly used on Soviet ballistic
missiles). ...In the end, Gringauz won over his opponents, partly
because everyone agreed that a high frequency
transmitter would ensure that the radio transmissions would be heard
around the world. The transmitter hardware was built by one
of Gringauz’ youngest engineers, Vyacheslav Lappo..."

>From other sources we know the transmitter used vacuum tubes rather
than transistors. This site mentions that when the received signal
was quite strong, the presence of a back-wave while the other
transmitter was keyed could be noted.


The RF oscillator, at a minimum, must have been free-running. So,
we're talking a vacuum tube crystal-controlled oscillator and a PA
having an input power of 1 watt. They may have used a PA driver stage,
or perhaps a frequency multiplier stage. If they did use a multiplier
then it must have been allowed to free-run as well. But given the
battery drain considerations, I would have done my best to reduce the
number of vacuum tube heaters, or filaments to a minimum. As such, I
think there's a fairly good chance this was a simple, MOPA design
(oscillator-> PA).

I found what might be a photograph of the transmitter on page 26 of
the December 1957 issue of the Soviet "Radio Magazine." Perhaps our
Russian speaking group members can confirm this and provide us with
other clues appearing in the article text? The magazine can be
downloaded at


Click-on ''Radio'',1957,N12.[djv].zip. The "zipped" December issue
appears in DJVU format. Don't miss the nice Sputnik cover art.

This re-post talks about the center-fed Vee dipole used (the 15m
transmitter used the 5.8meter dipole) among other things.


Getting to get the point, this morning I woke up thinking about how
plentiful vintage Russian military tubes are these days. Remember how
inexpensive US military surplus used to be? That's how it is right now
with Russian components (and the characteristics of some of these
tubes are simply amazing). All I can say is get 'em while they're hot,
as it surely won't last forever.

It also came to me that Expanded Spectrum Systems sells an HC49
crystal cut for 21060kHz for two and a half-bucks each.

Finally, I remarked to myself that propagation-wise, 15m may well be
open for business come the 54th anniversary of the launch of Sputnik-1
next October the 4th.

You've probably guessed by now what I'm going to propose. We have
plenty of time to throw together a simple 15m CW vacuum-tube
transmitter having an input power of 1w or less. We could use any
tubes that we like but I'm going to build mine using 1950's vintage
ex-Soviet devices. I plan to power mine with one or two of those
ubiquitous 12V sealed-lead-acid batteries. I'll VXO my crystal and
I'll let it free-run during transmit; both for historical reasons and
to improve the signal quality.

Perhaps some of the antenna gurus here would lend a hand by modeling
and testing something akin to the original 70 degree Vee dipole? Would
this be a practical antenna?

I propose that beginning on "Sputnik Day" we launch our 1 watt Sputnik
clones on 15m CW. Instead of calling CQ, our call could be along the
lines of "Beep_Beep_Beep_Beep_Beep_Beep de AA1TJ". In other words, six
letter E's followed by our call sign. Given that I can barely organize
the socks in my underwear drawer, perhaps someone skilled at
organizing events would take up the cause?

One more thing. Poking around on Google last night, I was struck by
how many people remarked that the experience of Sputnik had changed
their lives. Some decided to become engineers, scientists or amateur
radio operators. I didn't know it at the time, but Sputnik changed the
way that I was educated. Not only did this little QRPp transmitter
make a tremendous impact on the world, but radio amateurs were front
and center. It seems appropriate that we should commemorate this
extraordinary day in the history of QRPp.


(they were seeing the orbiting booster stage rather than the satellite)

Sputnik Mania...the complete film in two parts (warning...contains
some political "button-pushing")
Greetings Space Historians!
We are a group of radio amateurs and we probably rival you in our
technical geeky-ness. We are now involved in an effort to re-create
and put on the airwaves replicas of the 20 MHz transmitters used in
Sputnik 1. (We will use the amateur radio 21 MHz band).
We are trying to find a schematic diagram for the transmitter. Can
you help us? Thanks.


If I happen to learn more about the original transmitter I'll be sure
and post it on my blog or web site. I found particularly interesting
the fact that WWV interrupted some of their 20MHz transmissions in
order to accommodate Sputnik's signal; a gentlemanly thing to do

As for the possibility of an event along these line, any comments or
discussion is most welcome. I plan to make a start on my little
Sputnik sender upon my return from vacation in July.
Greetings Space Historians!
We are a group of radio amateurs and we probably rival you in our
technical geeky-ness. We are now involved in an effort to re-create
and put on the airwaves replicas of the 20 MHz transmitters used in
Sputnik 1. (We will use the amateur radio 21 MHz band).
We are trying to find a schematic diagram for the transmitter. Can
you help us? Thanks.

Ha...I just received several fairly good-quality color photos of the
original Sputnik transmitters! At first glance it looks as though they
used two subminiature pencil tubes! The quartz crystal looks very
similar to our HC-18/u package. The RF portion is very simple in
appearance. In fact, it reminds me of something you'd find in a 1950's
ARRL Mobile Radio Manual! ;o)

The fellow who sent these apparently has a contact with one of the
original Sputnik (non-electronic) hardware designers; who is said to
be "still very much alive." My contact is going to make an inquiry
with his Russian contact about the transmitter.

Very cool...

Mike, AA1TJ


  1. The Kansas Cosmosphere has the flight-ready backup of Sputnik 1. I would think they would have significant documentation of what's inside.

  2. Wow, an actual Sputnik HERE?! That's amazing. Sure would be neat if they documented the details of the electronics.

    OK, so who will contact them? I'm game but I don't want to step on anyone's toes.

    73.......Steve Smith WB6TNL "Snort Rosin"

  3. Here is a link to the Kansas Cosmosphere in Hutchinson, Kansas that has on display the only genuine Sputnik I in existance. It was obtained directly from the Soviet space program. http://www.cosmo.org/mu_artifacts.htm
    The Kansas Cosmosphere has quite an assortment of space artifacts from the early Russian space program.
    Bruce - KK0S

  4. Hi Guys,
    Mike, AA1TJ here. Thank you Bill for for taking an interest in the Sputnik project. Wow, we have a Sputnik clone in Kansas. That's almost surreal!

    Yes, by all means can we get someone there to photograph the transmitter innards and trace the circuitry? That would be fantastic. I would have to think the curators would be willing to assist with such a request. It would be great to think it was a bunch of amateur radio QRP ops that documented the little 1watt Sputnik transmitters.


  5. Don't know if this is new info to you but there is a fantastic space race history titled "Sputnik, The Shock of the Century" by Paul Dickson.

    The author makes several references to hams and how they were able to hear the "beep-beep" of Sputnik as it passed overhead.

    A paragraph on page 129 might help with the quest for the schematic. It reads:

    It was a popular belief at the time that the Soviets chose the lower frequencies to allow ham operators around the world to receive the signals and track the satellite. This scheme, it was thought, not only popularized the project but also provided cheap worldwide tracking reports from hams around the globe. In 1990 Konstantin Gringauz, the man who designed the transmitter, confirmed the suspicion in an interview when he told Brian Harvey of Spaceflight magazine, "Korolev was adamant that signals should be received by as many people as possible throughout the world, including amateur radio hams." In addition, the Soviets had gone out of their way to make the frequencies known. As Gringauz reminded Harvey: "In the summer of 1957, announcements were made of the impending launch of Sputnik I. The June 1957 issue of Radio magazine...published a complete description of...its transmitters, and how to pick it up, but no one took it seriously."

    Someone, somewhere might have old issues of Radio magazine and it might have a schematic or at least a good description that will provide clues about the construction of the transmitter.


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