BRC/Thorn 3500 Chassis
Model: Marconiphone 4711
Original List Price : £000.00 ( to be ascertained)
CRT: A67 120X
The Actual Set
I bought this from the family of the original owners who got it in 1973. It was serviced by the local dealer, their stamp visible on the back of the set. Pretty much untouched since it was retired but sat in the owners lounge all these years, inside its has a thick layer of dust, perfect. The pictures don’t quite relay how big this TV is. It is in fact as big as the 1967 Decca CTV25.
Mazda A67 120X Health Check
As is customary before I do anything else and on which hinges whether the set will be repaired, “is the CRT OK with regards to shorts, filaments and emissions”.
This A67 120X should give a good account of itself with the Red and Blue guns giving a good reading. Green is slightly lower than the other two but may pick up with use.
I’ve had much worse readings on other tubes and those CRT’s have gone on to give excellent results. I always remember the RCA tube in the Baird M702, that had lower readings on all three guns than this tubes green. The Baird went on to give the best picture I’ve seen on a vintage early colour television. With this tube and the excellent 3500 chassis, I expect the results to be at least very good.
That’s it for now on this set until I get the HMV 2703 PSU sorted and off the bench, then this one will get its turn.
Possible reason for this sets retirement The multi-can electrolytic ( C602,C603, C606) has failed spilling its guts. Upon cleaning the dust away it reveals some repairs in the video supply rail, in particular R609 and W602. A new multi-can will be fitted and then power applied to the PSU on the test rig. That won’t be happening just yet as this set has to wait its turn in the queue. I just wanted to do an evaluation of the PSU.