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Vintage British Transistor

Ernst Erb Jürgen Stichling Bernhard Nagel 
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Forum » Radios and other type of sets (Physics) etc. » Devices: rare or unknown or self made » Vintage British Transistor
Clive Forder
Clive Forder
GB  Articles: 20
Pict.: 1037
05.Nov.13 23:06

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A rather handsome British "Transistor" radio from the 1950/60's. The Ebay seller is asking for help in identification. I would have said mail order kit but the circuit board looks too good for an amateur soldering job .Shame about that broken ferrite rod. No markings at all on the radio except for "RR164" on the case interior in black letters. Ebay item 141108185772. Can RMorg members name it? If so, I will pass on the information to the seller with our compliments.


Michael Watterson
IRL  Articles: 979
Schem.: 650
Pict.: 2497
06.Nov.13 10:42

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It's a PP8 style connector (2 x 6V), but for smaller PP11 2 x 4.5 ). The Feritte Rod aerial is easily fixed. It looks like a transistor version of the very late Co-op Defiant A3 Battery Valve  model. Except the Early Transistor Defiant Models listed don't look like that. But we have ones with no photo.

It doesn't look especially like a kit to me. Looks  late 1950s/Early 1960s Commercial UK model. But sellers says a Contessa "Kit". There were plenty of "kits" offered in early 1960s "Practical Wireless" but apart from "Heathkit" many were "remaindered" Production stock, not designed as kits. You can't see the soldering under the PCB anyway. But some early PCB production was hand soldered and not wave soldered.

The only Contessa Kit I find here is the Radio Constuctor Contessa (quite different).

But I find an Alba 22 with what looks like identical chassis. I searched for 6 transistor UK GB radios 1957  to 1963 under Advance Search, also looked at OC44 models first as that seemed likely looking at chassis. The Defiant A55 though (made by Plessey) is also the same chassis.

I'd suspect it's an unlisted Defiant given how similar cabinet it is to the Valve Portable Defiant A3 and same chassis as Defiant A55. It wouldn't suprise me if a number of different brands used the OEM Plessey Chassis. Plessey only sold Professional, Military, Telecom & Aerospace Radio sets uunder their own name. They made radios for other Brands from earliest days, sometimes entirely (Co-op Defiant) and sometimes excess demand that couldn't be met.

It may have been sold as a kit too, later.


A bit more searching reveals it was also used in a Magnavox 300TR as well as Defiant A55 and Alba A22 and A33.

There was indeed a Practical Wireless Kit Contessa MkIII. Simply the Plessey PCB and parts in a commercial case. Also sold by Henry's Radio. The kit cost was £11-10-0, Advertised by several companies in June 1961 Practical Wireless. Probably available completely assembled too.

It's possible the cabinet was designed for the Co-op (though at one stage they did make cabinets in 1950s, but never the Radio Chassis) and never used as it's a professional "mass produced" 1960 style.


Create it as Contessa MkIII model Kit with Practical Wireless as "Brand". We don't put OEM makers except in the notes. (All the Defiant sets would be Plessey not Co-op and many Ever Ready, Cossor, Marconiphone etc would be affected!).
Specifications can be copied from Alba A22 Alba A33, Defiant A55 models. They are the same. So "year"1961 is the year after the commercial version which was typical of "kits" using up remaindered stock.

Further Edit

The 1959 Defiant A5 uses earlier Ediswan style Transistors X series (top hats). The late version 1963 Defiant A55  uses OC44 types, which are the rounded top black tubes like miniature painted valves. So obviously the Contessa MkIII is the later type. One web page claims 7 transistors, but I can only see six. The Defiant A55 has a plate screwed to rear of tuning capacitor for speaker and car aerial sockets.

The PP11 is easy to replicate with a printed cover on a card box, sockets made of cut up coffee tin and two sets of 3 x Alkaline AA  in holders will fit. No need to "spoil" the  4 pin connector. In the late 1970s a lot of Radio sets using PP11 had the speaker wiring changed and plug swapped to use a single PP9. This can easily be reversed.


This article was edited 06.Nov.13 11:35 by Michael Watterson .

Howard Craven
Howard Craven
GB  Articles: 108
Schem.: 9057
Pict.: 17426
11.Apr.21 10:43

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This transistor set is a Contessa, a mail order kit sold by Henrys Radio Ltd, London in 1960-1. A model page has now been created.