THE FABULOUS 50S AND HOW TO GET RID OF SOME REALLY BIG BOATANCHORS

Posted by STEVE MYCIUNKA on

The fabulous 50s was a wonderful time for the radio enthusiast as most towns had a surplus store selling contains of ex military kit and if you were in the big smoke, well Lisle Street and immediate environs were your oyster.  The 50's were also a time of scientific optimism where we had fanciful ideas like using atom bombs to excavate tunnels through mountains and build roads and then there was the look skyward to the heavens.

Early 1957 was particularly noteworthy and the Sputnik launch on 4th October 1957 changed the World forever.  First we had the agog astonishment that the Russians had beaten the Americans into space - that took the wind out of the sales of poor old  U.S. President Dwight D. Eisenhower who had announced through his press secretary on 29 July 1955 that the United States would launch an artificial satellite during the International Geophysical Year (IGY) - oops.    This resulted in quite a deal of shock and panic once the initial novelty wore off: -

 

The launch of Sputnik then heralded a good deal of marketing on the other side of the pond, after all, who could resist this - what was the small dog - Pomeranian or a Shi-Tzu (Joke): -

 

On this side of the pond, Sputnik busily beep-beeping over our heads was also a marketing opportunity for those nice chaps in Lisle Street and the other surplus shops the length and breadth of this sceptred isle.  People would want to listen to this satellite - and the next one that the Soviets sent up.  And let's face it, with Sputnik transmitting at 20.005 and 40.002 MHz, there were plenty of really good surplus receivers capable of resolving these signals quite nicely.   However, there were also some large heavy lumps that no-one really wanted which were too good to be stripped and too heavy to be used as doorstops, yes, you've guessed it the R208: -

Without exception, the surplus emporia universally dubbed this lump the Sputnik Special which was a slimline 40kg in mass.   They mercilessly pushed the sale of these to any Sputnikophile who was desperate to listen.   This leviathan allowed you to trundle around the frequency ranges in 3 bands: 10-20, 20-40 and 40-60 MHz.  

Handily designed to run using AC mains as well as 6VDC  (Filament voltage is 6.3V, with smoothed HT quoted at 205 VDC) this was boon to the non standardised electricity supply extant in the UK at this time - anyone could plug it in and use it with a little ingenuity     The receiver features an RF stage,  an IF frequency at 2MHz, with the BFO running at 500 KHz..  The valve line up used convenient ex-Service types such as an EF39 (ARP34), a 6K8 mixer, followed by 2 IF stages utilizing another EF39 and the pentode of another 6K8. The 6K8 triode functions as a BFO for Morse reception.  A 6Q7 is used as a triode audio amplifier, with the 2 diode functions being used for detection and AVC. A 6V6 is used for the audio output stage.  The audio output is 2 watts to the internal loudspeaker with provision for 2 sets of low resistance headphones so an excited ham and XYL could listen simultaneously and be close on hand to celebrate reception of the beeps from on high (!). Line output at 600 ohms was also provided.  Aerial input impedance is quoted as 80-100 ohms. The recommended aerial is a dipole, preferably coaxially fed. 

I personally do not rate this big silly lump but have to grudgingly admit it's ready made for vintage patrolling of the 6M band.

Some people have an R208 partnered with an equally vast receiver, the R107 and interestingly, for the amateur that had these, well, he or she would have a receiver ensemble that virtually identically matched the mass of the Sputnik satellite at 83.6 kilograms (184 lb) - that's a nice little factoid that I'll bet none of The Chasers knows - there again, I can't imagine this topic coming up on that particular TV show either.

Do I hanker for an R208 and R107, of course not, I'd rather have the Sputnik!!!!!

 

 


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