Ekco TS701.

[Geordie McBoyne]

Today, I removed the chassis from the cabinet of the Ekco TS701, the vision and sound model.
Compared with the TA201 a considerable number of components are located on the power and timebase chassis assemblies in different positions.
Most noteworthy are the EHT smoothing capacitors, particularly the position of the EHT reservoir capacitor! Some form of protection from that component is essential.
In the TA201 the high voltage capacitors are well away from prying hands. Not so with the TS701.

Geordie McBoyne.

[CambridgeWorks]

What a lovely clean chassis!
How old is it?
Rob

[Geordie McBoyne]

"What a lovely clean chassis!
How old is it?"
Hi Rob,
Set was made in either 1938 or 1939. I'll look for date codes during the restoration process.
The chassis is in much better condition when compared with the TA201.

Geordie McBoyne.

[LENINGRAD T2]

The designers of the TSC30 probably took inspiration from this model.

[Geordie McBoyne]

From a 1938 sales catalogue, the 12" console version of the TS701, or rather the 9" TS901.
The model TSC30 is essentially the same as the pre-war model TSC902. Main differences are the B5 base rectifier valves are replaced with Mazda Octal types. U21 replaced by U22 and UU5 replaced by UU7. The rest of the circuit is more or less the same as the pre-war set.

Geordie McBoyne.

[LENINGRAD T2]

Information from 1939
   

[Panrock]

From a 1938 sales catalogue, the 12" console version of the TS701, or rather the 9" TS901.

I've always thought this to be a most attractive console. Is it known what 12-inch tube was fitted?

Steve

[Geordie McBoyne]

"I've always thought this to be a most attractive console. Is it known what 12-inch tube was fitted?"

Hi Steve,
if the console model was released in 1938 the CRT is most likely to be the Mazda CRM121.

Good progress with the TS201 today. The 8mfd timebase HT supply reservoir capacitor was known to be faulty and has been replaced with a motor run capacitor. Taking your advice in an UKVRRR topic an RS Components component is employed. It fits neatly inside the old wet electrolytic can. The part number is: 377-8914.
Also requiring attention were the timebase valves heater cables. The perished insulation replaced with heat shrink sleeving.
After more pre switch-on checks a small picture appeared in the screen. After replacing many more components the picture almost fills the screen. Timebase HT voltage is 245V, this might be a bit on the low side.
Since the off-screen pictures were taken this afternoon the picture width has again become much reduced. One component that is often forgotten is the capacitor in the line linearity circuit. In the Ekco it's a 0.01mfd capacitor and will be of a high voltage pulse rating, say 800V.

Geordie McBoyne.

[Panrock]

David,

Nice fit - that motor run capacitor!

Thanks for answering my question. As for the CRM121, I have a customer who visited RACS with me, and who paid for several successful rebuilds of that tube, including re-screening and added aluminising. I suppose that means they're really now CRM123s! I presume he's still got them.

Steve

[Geordie McBoyne]

The capacitor C45 has according to the Simpson 260 multimeter a 50Kohm leak. The capacitor will be replaced today.

Geordie McBoyne.