22-10-2015, 04:17 PM
(22-10-2015, 05:56 AM)Crackle Wrote:(21-10-2015, 04:31 PM)Nowhere-Man Wrote: ..................... I have a floating cathode wire and I assumed this must connect to the second lug on the can. Otherwise I'm baffled as to why my 2nd cathode wire measures 400 volts and is soldered onto an empty terminal on a connector block..
This "floating" wire maybe the one which needs to connect to R20 and then another wire from R20 goes to C34, which is in the other smoothing can in front of the tuning cap, follow it and check, if so reconnect it to the rectifier output and you may have HT to the rest of the set.
I find it helps to take photos or make a quick sketch on paper before dismantling anything.
Mike
It has to be very specific for me or I won't understand. Detail is everything. I spent some time searching online and simply wasn't getting the specifics I needed for this. I was forced to go about it a different way.
Taking the GEC as an example, some time ago I used a silicon rectifier and capacitor/resistor network and fed the cathode D.C. ripple to the corresponding lug on the single smoothing can. I tested this can last night and found I had the same 3 lugs or terminals, one being ground. I found the voltage on the supply feed lug was about 280. However, the voltage on the second lug was about 200 volts. So definitely two potentials at work, the latter being dropped across the circuit.
Suffice it to say, the design around the can is quite different from what appears to be the case with the HMV.
To further clear a few things up, I took the first 16 mF smoothing can out of circuit, except ground. I then manually charged the first terminal "A" of the capacitor for a few minutes. On measuring with the a meter, "A" was holding the voltage of the charge. "B" was zero potential. Negative was at ground.
Next, I manually charged terminal "B". After a few minutes, "B" was holding charge without any problem.
Between "A" and "B" was zero potential difference, as was expected as both had been charged.
That's what I needed to know.
The resistors mentioned I tested some time ago - one is between the two cans.
It seems as if someone has messed with the rectifier circuit junction bridge and removed some small junction wires.
It now seems wise to test the second smoothing can out of circuit.
