Sputnik 1
 

The world’s first satellite, Sputnik 1, was launched on October 4, 1957, by the then Soviet Union that heralded it as a national triumph, and started the space race.

Not only was this an important achievement, but an historical milestone that opened space exploration.

The Russian language Radio magazine for radio amateurs published articles on the proposed telemetry system and the intended downlink frequencies. An English language version later appeared in the QST magazine of the ARRL.

The United States also revealed its intent to launch a satellite during the International Geophysical Year 1957 – but the USSR was first.

When launched it had four external antennas to transmit on 20.005 and 40.002 MHz at about 1 watt heard throughout the world by radio amateurs including those in Australia.

Sputnik, a 58 centimetre diameter polished metal sphere, was seen from Earth as it travelled 29,000 km/h taking 96.2 minutes for each orbit. It had no stabilisation system.

There were two aluminium casings that bolted together using a seal to create an air tight housing for two transmitters plus a simple temperature and pressure sensing system.

Scientists studying it garnered information, like the density of the upper atmosphere deduced from its drag on the orbit, and the propagation of its signals that helped better understand the ionosphere.

At a time the WWV time and frequency standard station near Fort Collins, Colorado USA stopped its night transmission on 20 MHz to avoid interference with the telemetry.

The signals continued for 21 days until the life of three silver-zinc batteries, two for the transmitters and the other for ventilation, ended 26 October. Sputnik burnt up and re-entered earth’s atmosphere on 4 January 1958.

To commemorate Sputnik 1, special callsign R60SAT will be on air from October 1 to 8. For further information including the awards available, please visit the qrz.com website.

Jim Linton VK3PC


PS I have 2 x R208 sat here from that era

Re: Sputnik 1
 

Yes I heard the 20 MHz signal, I also saw the trail in the sky, I thought it was the satellite but have since been told it was the launch rocket traveling somewhere behind Sputnik.

I don’t know which it was but I only heard the signal about the same time as the trail in the sky.

Re: Sputnik 1
 

Just think of all those channel B1 TV sets where a small adjustment on the fine-tuning control may have revealed the new space age from the loud-speaker...

Re: Sputnik 1
 

I thought the sound on B1 was 41.5MHz, so 20MHz seems a bit of a stretch for fine-tuning.

Re: Sputnik 1
 

40MHz?

Lawrence.

Re: Sputnik 1
 

But they could have heard the 40.02MHz Sputnik.

However back then pretty much all B1 TV transmitters were vertically-polarised, likewise the receiver-antennas - which would have had a significant polarisation-loss when trying to receive a transmitter located essentially straight-up!

Re: Sputnik 1
 

http://www.northantstelegraph.co.uk/...aser-1-6678765 The R208 covers 40 MHz etc. Time to fire it up!

Re: Sputnik 1
 

With the exception of travelling wave tubes, this could be the only valved satellite flown?

Re: Sputnik 1
 

I was 7 years old but I remember the excitement! I seem to remember my Dad tried manipulating the fine tuner ring on our 17-inch Ekco in an attempt to pick up something, but was unsuccessful.

Re: Sputnik 1
 

Not all sets had the full complement of biscuits fitted, so depending where you lived CH1 might have been inoperative.

Re: Sputnik 1
 

Here is the schematic:
ftp://ftp.radio.ru/pub/2013/04/55.pdf

Dave

GW7ONS

Re: Sputnik 1
 

Interesting point Bill.

The US made a point in their advertising of Nuvistors and use in the Mercury missions pre-Apollo,wonder if they did use them in satellite tech as well? I bet they did.
Fascinating how Sputnik used the rod pentodes and how well it all functioned on battery power alone inc powering onboard fans.
60 years ago, well, how time passes....

Re: Sputnik 1
 

True. However, this was in Sundridge, near Sevenoaks, and Crystal Palace Ch.1 was our BBC transmitter.

Of more concern would have been the likely poor overhead response of our loft aerial and of course, the need to listen at the right time. I presume the tuner had a relatively broad sound IF bandwidth and this might have helped obtain reception, of some sort, down to 40 MHz.

Steve

Re: Sputnik 1
 

I'm not sure Nuvistors were used in any satellites. Videcon tubes were the eyes of many early weather satellites though.

What RCA often failed to mention in their ads was that the Nuvistor tubes were actually part of the ground receiving equipment instead of satellites. However, they did make it into some other spacecraft and RCA did make some specialty tubes for Mercury onboard radios. And, the Soviets copied many Nuvistors for use in their equipment for decades.

If I remember correctly the first US satellite, Explorer I, was originally designed to use small long lead glass tubes. However, before its first launch it was redesigned for transistors.

Re: Sputnik 1
 

One of the most interesting books I've ever read is called Sputnik: The Shock of the Century by Paul Dickson. It describes the roots of the US-Soviet space race and the earliest unmanned missions.

Re: Sputnik 1
 

... yes, I was thinking of the 40 Mc/s signals with regard to B1 set fine tuning ...

As for getting the right time to listen for the short duration the sputnik would have been above the horizon - now there was a challenge in 1957!

Re: Sputnik 1
 

Apologies that I had been distracted away from the 40MHz signal (mentioned in the OP) by subsequent discussion of the 20MHz signal.

Re: Sputnik 1
 

I did read of a proposal to use valves for at least some of the electronics of a probe for landing on the surface of Venus or Mercury, where the surface temperature is greater than the maximum operating temperature of semiconductors, but don't know if it was implemented.

Re: Sputnik 1
 

I think there will be quite a lot of coverage in the media today. They played a clip of Sputnik at the start of the Today programme this morning with an item on it to follow sometime.
Dave

Re: Sputnik 1
 

This is an interesting program about a school in Northamptonshire that tracked early Soviet satellites and calculated the launch site:
https://www.youtube.com/watch?v=59s_d7YVC6o&t=5s

Dave

GW7ONS