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  • Released 1939
  • 7-inch Mazda CRM71 C.R.T.
  • Single channel T.R.F.
  • 20 Valves.
  • A.C. mains.
  • Original Cost £27-6-0
A proper old television, from the era of small screens, "widow-maker" mains-derived E.H.T, thyratron timebases and loads of nice octal valves. Its also monsterously heavy, thanks to the three massive mains transformers and four huge DC chokes, however they did their best - they saved one transformer by driving the frame coils directly.

The set was released at a time when television really was starting to take off, aided no doubt by receivers of reduced cost through better design, valves designed for television and yes, some sets with smaller screens. The Mazda valves in this set include a selection of dodgy rectifiers that look more at home in radio sets, but the SP41's in the receiver section were a new high gain, high frequency type for Television use. Whilst not as famous as the EF50 which was to appear in the latter half of 1939, SP41's were indestructable and long lasting, performing well against some other offerings from the era (think Mullard SP4). Indeed, SP41's and their 6.3v sister the SP61 were soon to be used in great numbers in many military Radar and RF applications. See, Mazda was capable of getting something right sometimes.

Alower cost version - the TA201 - was basically the same but minus theaudio section, the owner connecting the set to the "gram" input of a seperate radio receiver. Whilst a number of TA201's survive, this TS701 is one of two known (plus a third modified fr a 9" C.R.T.) which suggests to me that cost reduction really was the driver behind the take off of television before the outbreak of World War II but a halt to it.
SERVICE DATA I have a copy of the manufactures so-called manual as well as the service notes from the Radio and Electrical Marketing supplement from May 6th 1939. You can download them from the Ekco manufacturers page.
CURRENT STATE Original condition, with a fine layer of dust (bar the more recent fingermarks on the bowl of the gassy CRT) and a broken width control.
December 2009 Wotton Bassett bash for a staggering £5200.
Rear view [37K] Power chassis [45K]
It doesn't take a genius to work out why this set is so darn
heavy - not only those three large transformers but there
are four D.C. chokes at the other end of the chassis!
R.F. Chassis [40K] Timebase chassis [45K]

All images copyright
J.Evans 2009
Last updated
17th December 2009