Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x


RCA 6K3 Preliminary Capacitor/Resistor Research

Mike,

This one shows -1.7V presently.  When I tested it before, it showed -0.4V.  This is one of those values marked with an asterisk to say that it can't be accurately measured because of the loading from the meter, but unlike the others, it doesn't show a value for what a meter so connected should read, even if not the true value.

Interestingly, for some reason, right now, without changing any components out, but simply it seems as a result of tuning back and forth and adjusting the volume, the voltage at the R14/15 junction has increased up to approximately 182V.  Consequently, my screen grids at 6A8 and 6K7 are now testing at around 90V.  Obviously, this gets the screen grids closer, but would this have an adverse impact on C16 or oscillator coil?  There's also a connection to the socket of the 6F5, but there's no pin on that position, so I suspect the 6F5 wouldn't care.  Not even sure why there's a connection to that pin all by itself.

The rest of the voltages throughout the other tubes seem to be closer to what is specified than they were when tested before, a couple weeks ago, though they weren't very far off to begin with.

I know there is some noise when adjusting the volume, so I'm wondering if some imperfection here might be sabotaging the testing.  Even though the 6A8 and 6K7 are in the RF section, the volume and tone controls do have a pretty direct connection to the start (R14) of the voltage dividing resistor - could these be affecting the voltage going into it?

I have some Deoxit D5 and F5 arriving soon.  I've seen F5 recommended for volume pots.  Maybe trying to clean that up will make a difference.

Best wishes,
Roy


Messages In This Thread
RE: RCA 6K3 Preliminary Capacitor/Resistor Research - by glyphmon - 05-28-2026, 02:49 PM



Users browsing this thread: 8 Guest(s)
[-]
Recent Posts
Philco 71 Code 125
I jumped the gun and stand corrected.RodB — 12:53 PM
Philco 71 Code 125
Ok guys. Thanks for the input. As for AI this is why I ask the experts. Dandconant — 07:39 AM
Philco 71 Code 125
Technically, that's C-. B- is chassis ground. The resistor between chassis ground and the HV center tap makes the HV c...MrFixr55 — 11:24 PM
54C Cabinet Refinish
hello Roy, I’d follow Arran’s suggestion and use automotive gasket material, which I keep around for situations like th...radiorich — 10:22 PM
Philco 71 Code 125
This might be one of those cases where it's a ground to an AC voltage and B- to DC.RodB — 08:22 PM
Philco 71 Code 125
Really Rod? I know you would not steer me wrong but AI say this is a short circuit? What if I moved the 6 volt center ta...dconant — 06:40 PM
54C Cabinet Refinish
Roy; Personally I would have left the asbestos alone if it were my set, but you can find a modern substitute that som...Arran — 04:51 PM
Philco 71 Code 125
Looks like that might be the B- buss, so that would be correct.RodB — 01:32 PM
Philco 71 Code 125
I noticed on the code 121 schematic the center tap for the 6 volt winding and hv winding are tied together. Is this corr...dconant — 12:16 PM
Philco 45-6365 Universal IFT Instruction Manual
The Philco Parts Catalog for 1942 shows it as usable for 175 kHz, 260 kHz, and 465 kHz. The instructions will show how t...DaleHCook — 11:19 AM

[-]
Who's Online
There are currently no members online.

>