20-12-2011, 08:50 PM
Back to work 
The next job was to sort out the connections and do a bit of tidying up. After that it's just a matter of getting connecting everything up and getting on with testing.
Just to recap the set consists of four units; The PSU, The Speaker Assembly, the Main Chassis (Valve Platform in Pye terminology) and the Frame Aerial. The wiring between these had been disconnected, as Pye advises, by either Joe or me. Despite having labelled and photographed I decided I'd better recheck, and it all looked fine, with three exceptions.
First here is a cable between the PSU and the Main Chassis. This has four black wires with coloured traces in it. When I was disconnecting I blithely chopped the wires off at the Main Chassis end - well, they're bound to be connected to tags behind the Paxolin panel, and the loss of 1/2" is no problem. It turns out that that's not the case at all. The wires are connected directly to their destinations in the set. So, I'll either have to rejoin them - Heat shrink - or make a new cable.
Second, someone had done a bit of jiggery-pockery with the PU Socket wiring. There were a couple of bits of dangling bell flex, one to the 'Live' socket and one to the wire to the set. That was easy to undo, just a bit fiddly.
Finally, while I was working on No. 2 I noticed a very unhappy looking resistor - see attached. The Trader and Pye sheets give a different layout for the Group Board, no doubt reflecting the modifications that were done during the life of these sets. This one appears to be somewhere in between. As far as I can tell from the wiring it's R2, which is the bottom half of V1 Screen Pot. Divider. I measure it at 50k. which is miles out. Also, I can't see how it could have been damaged, unless there was a serious valve fault at some stage. Anyway, I propose to leave it for now and see what the Screen volts are.
So, connect and fire up next
Alan
GroupBoard1.JPG (Size: 3.24 MB / Downloads: 98)
The next job was to sort out the connections and do a bit of tidying up. After that it's just a matter of getting connecting everything up and getting on with testing.
Just to recap the set consists of four units; The PSU, The Speaker Assembly, the Main Chassis (Valve Platform in Pye terminology) and the Frame Aerial. The wiring between these had been disconnected, as Pye advises, by either Joe or me. Despite having labelled and photographed I decided I'd better recheck, and it all looked fine, with three exceptions.
First here is a cable between the PSU and the Main Chassis. This has four black wires with coloured traces in it. When I was disconnecting I blithely chopped the wires off at the Main Chassis end - well, they're bound to be connected to tags behind the Paxolin panel, and the loss of 1/2" is no problem. It turns out that that's not the case at all. The wires are connected directly to their destinations in the set. So, I'll either have to rejoin them - Heat shrink - or make a new cable.
Second, someone had done a bit of jiggery-pockery with the PU Socket wiring. There were a couple of bits of dangling bell flex, one to the 'Live' socket and one to the wire to the set. That was easy to undo, just a bit fiddly.
Finally, while I was working on No. 2 I noticed a very unhappy looking resistor - see attached. The Trader and Pye sheets give a different layout for the Group Board, no doubt reflecting the modifications that were done during the life of these sets. This one appears to be somewhere in between. As far as I can tell from the wiring it's R2, which is the bottom half of V1 Screen Pot. Divider. I measure it at 50k. which is miles out. Also, I can't see how it could have been damaged, unless there was a serious valve fault at some stage. Anyway, I propose to leave it for now and see what the Screen volts are.
So, connect and fire up next
Alan
GroupBoard1.JPG (Size: 3.24 MB / Downloads: 98)
