28-07-2015, 08:32 PM
(This post was last modified: 28-07-2015, 08:38 PM by Geordie McBoyne.)
Hi Trevor,
I'm delighted that you are pleased with the Ekco TSC30A. For all intents and purposes this is a pre-war TV set, in fact the circuit is almost identical to the 1939 model TSC902. The main differences are in the type of CRT employed. In the TSC902 the CRT was the Mazda CRM91 and in the post-war version the CRT is the Mazda CRM92. Interesting to note the earlier tube has a 63 degree deflection angle and the later tube is 58 degrees.
If you are looking for an over engineered TV receiver this the one. For starters it has three mains transformers, vision, sound and EHT. Many small screen TVs used a fairly modest frame output valve, a triode like the 6SN7GT, ECC33 etc. Not this set, a mighty PEN46 is employed and believe or not there is only just sufficient height available. That has to be a fault condition.
The TSC902 and the original TSC30 as mentioned earlier are almost identical except for cabinet presentation, the TSC902 has a darker finish.
The slightly later TSC30A has the added refinement of a sound interference limiter, a rather special one called the Dickert circuit. A Mazda DD41 double-diode is employed. Andy (Radioman) expressed an interest in this circuit for radio applications.
The operation of the Dickert circuit is described in the Spreadbury TV servicing book.
The Mazda UU7 is electrically similar to the UU5, only the base differs, MO and B4 respectively. I think the TSC902 also employed the UU7.
The set has an interesting history. Way back in 1998 I got a tip off that a pre-war set had turned up. Imagine my surprise when I got first sight of the set, the cabinet had been cut in half and only the upper section has survived. Not being put off by that I set about making a new cabinet, new sides, cabinet base and the shelf for the very heavy chassis. Only the upper front and top parts are the original.
Like the chassis the cabinet is of massive construction, 3/4 thick plywood is used throughout. The complete set weights more than one hundred weight! The set was delivered to Trevor with chassis out of the cabinet. No more mad weight lifting stunts for me anymore, I can't even lift my Black and Decker Workmate anymore. At least not in the manner I used to lift it.
I've still got the Polaroid pictures of the cabinet construction, when I find them I'll post up the pictures on the forum.
The most recent jobs on the set were the new back covers and the loudspeaker cloth.
Read about the cabinet back here: http://www.vintage-radio.net/forum/showt...p?t=117456
All the valves employed in the TSC30A are Mazda octal 4 volt heater types. SP41, DD41, T41, PEN45 and PEN46. The EHT rectifier is an U22.
Geordie McBoyne.
I'm delighted that you are pleased with the Ekco TSC30A. For all intents and purposes this is a pre-war TV set, in fact the circuit is almost identical to the 1939 model TSC902. The main differences are in the type of CRT employed. In the TSC902 the CRT was the Mazda CRM91 and in the post-war version the CRT is the Mazda CRM92. Interesting to note the earlier tube has a 63 degree deflection angle and the later tube is 58 degrees.
If you are looking for an over engineered TV receiver this the one. For starters it has three mains transformers, vision, sound and EHT. Many small screen TVs used a fairly modest frame output valve, a triode like the 6SN7GT, ECC33 etc. Not this set, a mighty PEN46 is employed and believe or not there is only just sufficient height available. That has to be a fault condition.
The TSC902 and the original TSC30 as mentioned earlier are almost identical except for cabinet presentation, the TSC902 has a darker finish.
The slightly later TSC30A has the added refinement of a sound interference limiter, a rather special one called the Dickert circuit. A Mazda DD41 double-diode is employed. Andy (Radioman) expressed an interest in this circuit for radio applications.
The operation of the Dickert circuit is described in the Spreadbury TV servicing book.
The Mazda UU7 is electrically similar to the UU5, only the base differs, MO and B4 respectively. I think the TSC902 also employed the UU7.
The set has an interesting history. Way back in 1998 I got a tip off that a pre-war set had turned up. Imagine my surprise when I got first sight of the set, the cabinet had been cut in half and only the upper section has survived. Not being put off by that I set about making a new cabinet, new sides, cabinet base and the shelf for the very heavy chassis. Only the upper front and top parts are the original.
Like the chassis the cabinet is of massive construction, 3/4 thick plywood is used throughout. The complete set weights more than one hundred weight! The set was delivered to Trevor with chassis out of the cabinet. No more mad weight lifting stunts for me anymore, I can't even lift my Black and Decker Workmate anymore. At least not in the manner I used to lift it.
I've still got the Polaroid pictures of the cabinet construction, when I find them I'll post up the pictures on the forum.
The most recent jobs on the set were the new back covers and the loudspeaker cloth.
Read about the cabinet back here: http://www.vintage-radio.net/forum/showt...p?t=117456
All the valves employed in the TSC30A are Mazda octal 4 volt heater types. SP41, DD41, T41, PEN45 and PEN46. The EHT rectifier is an U22.
Geordie McBoyne.
