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Blog posts of '2014' 'February'

THE MIGHTY ROHDE & SCHWARZ EK-07

 Well, evidence of my advancing years crept up on me and was revealed today when I ran out of puff trying to move my Rohde & Schwarz EK-07 receiver.  Widely acclaimed by some as the best valve communications receiver made, I am priveledged to have one courtesy of my friend Norman Varnes (G4YXX) who tells a tale of spirited bidding over a glass or several of jenever at the famed Helmut SInger emporium to liberate it with a terrible sacrifice not only in pounds sterling but also a most horrendous hangover courtesy of much falling down water consumption during the lengthy negotiations necessary to secure this leviathon. 

For those that are not 'in the know', here's a little history lesson.......  The year is 1957. Rohde & Schwarz, founded in 1933, introduced the EK 07 shortwave receiver. This milestone set the benchmark for precision engineering in the radiocommunications market. Frequencies could be read with high accuracy, image frequencies were a thing of the past, the radio was immune to overload, and sound quality was above average. This was reason enough for the German Armed Forces to adopt the EK 07 as its standard communications intelligence receiver beginning in 1962.

Indeed, my EK-07 has an interesting provenence as it came from the renowned Norddeich DAN German maritime radio station and did sterling service until being demobbed on station closure in 1998.  Here is a nice photo of a bank of EK-07 in action at DAN: -

 

And here is an even nicer photo of the EK-07 production line at R + S in 1961: - 


Finally, here is my baby - a true representation of a boatanchor weighing in at 75kg: -

 

Thanks are also due to my friend Brian Harrison (KN4R) who has helped me out with an English translation of the weighty EK-07 manual so I now have no excuse to not check this over to ensure all is in spec for the next 50 years of operation - time to get weaving!!

 

 

 

I SAY, BASE ADAPTORS FOR YOUR VALVE TESTER - SIMPLY SPIFFING!

 

May 1854 brought a useful accessory addition to the Mullard High Speed Valve Tester (MHSVT).  Developed in conjunction with Messrs. Spear Engineering of Warlingham the range comprised of eight adaptors to facilitate the testing of valves for which no existing valve base was provided on the instrument.

These were precision items, with the bodies of the adaptors being trned from duralumin - usually reserved for aircraft bodies - and just look at the adaptor below for testing the EY51 boost diode - impressive huh?

The adaptors were engraved 1-8 with the figures clearly identifying each adaptor body and were priced at £4. 2. 6d. (£4.125)  the set complete in a holding rack.   otherwise the adaptors were available idividually at prices ranging from 7s. 6d (37.5p) to 15s. 0d. (75p)

MULLARD AUDIO VALVES ON TOUR IN 1954

Today's photograph from the annals and archives of Mullard is a press photogaph from early 1954 where Mullard representatives chatted animatedly with Mr A J Walker Hon. Secretary of the Association of Public Address Engineers at the Mullard Stand during the APAE exhibition.  It was recorded that Mr Walker was very excited by the possibilities that the EL84 presented to the world of PA: -