Quote:
Originally Posted by Kevin Kuehn
You really don't want to run the set with the output transformer removed other than to take quick measurements because the 5AQ5 screen grid(pin 6) is still getting B+ and it's not healthy for the tube without the plate also getting B+. I really can't follow what you mean when you say everything after C50 is negative? Exactly where are you measuring negative voltage in respect to B- ?
I'd like to suggest we focus only on this little section instead of jumping all over the map. C50 is only a audio coupling cap that passes audio from the detector stage to the volume control, so we're really not worried about anything other than this little portion of the schematic. Once we figure out what's ailing the audio output then we can move onto the bigger picture.
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OK so what I mean by the voltages after C50 are all Negative is that part of the B+ (245V supply) line goes into TS8-4 which is also where one side of C50 goes in at as well as R54 and R56 and C3B tie in at, and at TS8-3 which is where the other side of C50 comes out (and also where the other side of the 245V supply comes out to supply the 5AQ5 tube with its necessary voltages) is where all of the voltages end up measuring negative, as for my B- reference its where the black wire coming from the power switch ties to the chassis and to the "chassis ground" for the old C3 can (which is out of circuit), and using that B- reference point is giving me negative voltage readings on the TS8-3 side of C50/245V supply line unless I reverse my probes (positive red probe to B- reference and the black negative probe to the voltage reference point).
Now I don't know how I can make that any clearer than that but I'm telling you that's what's happening to me with this TV.
12-08-2021, 12:18 AM
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