Sputnik 1

[G6Tanuki]

Originally Posted by egrandUS

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.

Yes, the US were rather enthusiastic at adopting transistors for satellites - see http://semiconductormuseum.com/Photo...ransistors.pdf for example

[G6Tanuki]

Originally Posted by ParcGwyn

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

Interestingly-simple circuit: pretty much the same as was being used for battery-powered 27MHz radio-control transmitters at the time. It'd be interesting to try recreating it and seeing how well it would work on 28MHz.

[Bazz4CQJ]

What made it go "beep-beep"? Was it just switched CW or was there some modulation applied? Everytime I've ever heard recordings of it they've always been the same slightly chirpy tone, but it may be that one original recording has been widely reproduced for radio/TV use.

B

[G6Tanuki]

I wonder what the Russian words above the ~off-board connection~ associated with the 2 output valves grids and C17 was connected to?

That it's explicitly described in words rather than just having a voltage associated with it makes me suspect it could be for modulation of some sort.

[Nuvistor]

It was definitely a beep, I was listening on a AM radio with no bfo. This one looks very like the radio we had, a Ferguson with a few short wave bands.

[G6Tanuki]

Some more info here: http://hamradio.qrz.ru/viewtopic.php?id=625

[ionburn]

Originally Posted by ParcGwyn

This is an interesting program about a school in Northamptonshire that tracked early Soviet satellites and calculated the launch site:

I remember Kettering Grammar School. They became quite famous at the time!

[VT FUSE]

I read a few articles from the amateur radio press over last five or so years,a google search for "Sputnik ham radio QRP transmitter" brings up a number of articles, forget frequency they were on but recall a number made successful QSO's.

Awash here with the rod pentodes used in the articles.

[turretslug]

Originally Posted by G6Tanuki

Yes, the US were rather enthusiastic at adopting transistors for satellites

Well, can't really blame them, much as there are many thermionics fans here- when every gram hurled expensively into space has to justify itself, extra power requirements for making metal glow get a jaundiced look when there are new-fangled devices available that dispense with that bit. The Soviet Union's first space rockets were notably large and powerful compared to their US counterparts, too, as they were originally intended for heavy, less developed nuclear payloads and their bulky re-entry vehicles with low-tech ablatives which allegedly included thick layers of oak heartwood and slabs of copper! So valves and their power sources would have been less of a game-stopper on the "other side", Sputnik 1 amounted to a heavy battery pack that was most of the weight and a bit of electronics.

[turretslug]

Originally Posted by emeritus

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.

It would indeed be interesting to hear of the technology involved in the Venus probes- ISTR, the atmosphere on Venus amounts to 100 bar sulphuric acid vapour at 400+ degrees Centigrade, so no mean achievement to get anything to work for long once landed! The Soviet Union got varying degrees of success with landers, I gather one transmitted for around two hours and that it was essentially a titanium pressure vessel.

[G6Tanuki]

The US Vanguard satellite's transistor beacon-TX was indeed simple.

It also worked on 108MHz which no doubt made the whole issue of efficient antennas a lot simpler.

It lasted from March 17, 1958 until May 1964, being powered by solar panels rather than Sputnik-style batteries.

I guess you could easily recreate this if you could find a non-whiskery AF117!

[VT FUSE]

Just searched for "Sputnik party transmitter" seems like most amateur builds were 21mHz (or 15m band).

Would have expected a re-run of this on 60th anniversary, many of us may not be around on the 70th anniversary or indeed the next decent sun spot maxima.

[MotorBikeLes]

Originally Posted by G6Tanuki

I wonder what the Russian words above the ~off-board connection~ associated with the 2 output valves grids and C17 was connected to?

Manipulation. So probably the beep-beep switching as you suggest.

Les.

[egrandUS]

Also, there was Project SCORE, which was launched in December 1958 and contained tape recorders that broadcast a special voice message from President Eisenhower.

Does anybody remember hearing that?

https://www.youtube.com/watch?v=2565DQg2_fk

[Nuvistor]

No I do not remember Project Score, that’s not to say I didn’t hear it on broadcast radio but no memory of it.

Thanks for posting, it was British Pathe film news which would have been shown in cinemas, cinema visits were are rare treat for me.

[Brigham]

It was the inspiration for a comedy film, where Ike's voice was swapped for a toothpaste advert, by Bob Monkhouse.

[G6Tanuki]

Not specifically Sputnik, but there's a fascinating video here:

https://youtu.be/YvFKzgF5t94

showing a Russian manned space-capsule recovery from somewhere in the Siberian wastelands (why did the Russians always land their missions on land whereas the USA returned to earth in the sea?)

Apparently made in 1988 - includes various stills and footage of what looks like an early GPS [GLONASS?] with 'blade' antennas on the recovery trucks and operators hunched over in-vehicle CRT displays, and a few static shots of computer-centres!

[egrandUS]

Originally Posted by G6Tanuki

why did the Russians always land their missions on land whereas the USA returned to earth in the sea?

A few reasons:

The interior of Mother Russia is far removed from the prying eyes of the free world. The Soviets usually didn't announce the end of missions until the capsule was safely back on earth so they could hide any failures.

Returning over land requires slower descent speed to avoid bouncing, which requires bigger parachutes. That meant more weight, fuel, complexity, etc.

The interior of the US is more populated than Russia. The landing zones of early missions, even when on target, were not that precise: at least 2 miles radius. There was a large possibility of going way off target too. The Americans felt the risk of hitting a populated area, or getting tangled in power lines or other infrastructure was just too great.

[dave walsh]

It's been claimed that returning to land [much later] hid failed missions involving humans. It's also been suggested that the US has an "off earth" set of personell. It IS a fact that when a Russian Pilot landed a Mig Fighter in Japan and asked for Asylum they laughed at the crude comms on board units that still used valves. Then it was suddenly realised that such primitive equipment could probaly withstand the EMF from a nuclear strike! At the beginning of the terrifying 80's film "Threads" you are in the Regional Control bunker in Sheffield Town Hall. The first thing to fail is the [Solid State] radio system.

Dave W

[ionburn]

I am not an expert with EMP's but I do wonder exactly how immune such equipment is. There are many components in a system, and as we know, semiconductors are not only used in transistors. Such a pulse would likely play havoc with radio altimeters, radar and normal radio reception to say the least.