Quote:
Originally Posted by Humptydumpty
G4EBT Dave now you tell me about the rectifier ,what is a rectifier and i will check it .And yes i did have a new meter . But i have not used it as yet .
But we are off again on another tangent . Do you think we should carry on ?
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You may be going off at a tangent - I'm not. I've said time and again that you should check the voltages and compare them to the circuit. A normal logical diagnostic approach with any set would be to do that, and to note any discrepancies, yet you now say "you've got a new meter but haven't used it yet".
Huh? I explained that the 'long thin blue thing that gets hot', is R37. I explained how to use your meter to check the resistance of R37, how to check the Voltage drop across it, and how to calculate the Wattage being dissipated by dividing the resistance into the Voltage. You clearly haven't done that, nor any other Voltage checks.
I mentioned the rectifiers because good place to start making Voltage tests is with the power supply, because if that isn't functioning correctly, none of the Voltages around the set will be correct. Maye I'm taking too much for granted in assuming that you'd know that the job of a rectifier is to rectify the AC current from the mains transformer output into DC. Sometimes solid state and selenium rectifiers can fail over time (as can valved rectifiers of course but not relevant here). Hence, as a starting point, it would be normal to check the AC input to the rectifiers (D6 & D7 on your set) and the DC output from the rectifiers with the meter set to DC Volts.
As shown on the attached clip of the circuit.
I've explained several times that you need to study the circuit, then identify the actual components you need to check. If you took note of that advice, you wouldn't have been asking what the 'long hot thing' was (R37) or what the rectifier was, because you'd see that D6 & D7 inputs are connected to the mains transformer secondary. D6 has C43 across it with the output is connected to R37. D7 has C44 across it, and it's output is connected to R38 (1K 4 Watts). Both D6 & D7 are connected to C42 (40µF).
To answer your rhetorical question 'do we think we should carry on?'
Well considering that I've urged you to carry out voltage and current tests, and though you have a meter but haven't used it, and considering that I've urged you to look at the circuit and relate it to the actual components, but you say 'a lot of it goes over your head', I see little point in my carrying on because my powers of persuasion seem totally inadequate, so I think I'll head for the exit.
There are lots of excellent books on vintage radio restoration, and on how to use a multi-meter.
Every good wish in sorting the set Trev, though you did say you were going to sell them, in which case everyone's time and effort has been wasted.