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

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Model 650 Tone Control Question
#16

I checked the AC voltages and they all seem good but I’m getting some strange DC readings. 

The first 42 output tube, red circle is giving me approximately 120 dc on both plate and grid. I say approximately because it seems to fluctuate. I have switched the 42’s around but the readings stay similar. The other 42 output tube, green circle, is giving me 365 dc on both plate and grid. No fluctuating there! The 42 driver tube is 246 on both the plate and grid.

The 6A7 is 250 on the plate, 86 grid and 2.45 cathode, 78 IF is 261 plate, 86 pin and 1.68 cathode, the 78 RF is 122 plate, 86 grid and 2.34 cathode and the 75 is 171 on the plate. 

Hopefully this provide some needed information for those of you that are much better at troubleshooting then I am. Please feel free to comment. I don’t have much experience but I do have thick skin so any advice is appreciated.


Attached Files Image(s)
   


Messages In This Thread
Model 650 Tone Control Question - by Hamilton - 06-27-2023, 10:45 AM
RE: Model 650 Tone Control Question - by morzh - 06-27-2023, 12:11 PM
RE: Model 650 Tone Control Question - by Hamilton - 06-27-2023, 05:49 PM
RE: Model 650 Tone Control Question - by morzh - 06-27-2023, 07:26 PM
RE: Model 650 Tone Control Question - by Hamilton - 06-29-2023, 08:03 AM
RE: Model 650 Tone Control Question - by RodB - 06-29-2023, 09:09 AM
RE: Model 650 Tone Control Question - by Chas - 06-29-2023, 10:26 AM
RE: Model 650 Tone Control Question - by morzh - 06-29-2023, 10:57 AM
RE: Model 650 Tone Control Question - by Hamilton - 06-29-2023, 11:46 AM
RE: Model 650 Tone Control Question - by RodB - 06-30-2023, 08:31 AM
RE: Model 650 Tone Control Question - by Hamilton - 06-30-2023, 11:45 AM
RE: Model 650 Tone Control Question - by Hamilton - 06-30-2023, 02:07 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 06-30-2023, 05:22 PM
RE: Model 650 Tone Control Question - by Hamilton - 06-30-2023, 07:57 PM
RE: Model 650 Tone Control Question - by Hamilton - 06-30-2023, 08:13 PM
Hamilton - by Hamilton - 07-03-2023, 10:13 AM
RE: Model 650 Tone Control Question - by Hamilton - 07-03-2023, 12:10 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-03-2023, 11:25 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-04-2023, 12:40 AM
462ron - by 462ron - 07-04-2023, 08:56 AM
Hamilton - by Hamilton - 07-04-2023, 09:54 AM
462ron - by 462ron - 07-04-2023, 10:06 AM
RE: Model 650 Tone Control Question - by Hamilton - 07-04-2023, 03:13 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-04-2023, 04:26 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-04-2023, 04:38 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-06-2023, 08:11 AM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-06-2023, 11:40 AM
RE: Model 650 Tone Control Question - by Hamilton - 07-07-2023, 07:48 AM
RE: Model 650 Tone Control Question - by Hamilton - 07-07-2023, 02:59 PM
RE: Model 650 Tone Control Question - by RodB - 07-07-2023, 03:11 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-07-2023, 09:23 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-08-2023, 09:30 AM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-08-2023, 12:07 PM
RE: Model 650 Tone Control Question - by morzh - 07-08-2023, 05:32 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-09-2023, 06:15 AM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-09-2023, 07:55 AM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-10-2023, 04:39 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-11-2023, 09:10 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-12-2023, 07:50 AM
RE: Model 650 Tone Control Question - by Hamilton - 07-12-2023, 12:20 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-12-2023, 05:58 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-12-2023, 06:46 PM
RE: Model 650 Tone Control Question - by Hamilton - 07-12-2023, 06:49 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-13-2023, 04:13 PM
RE: Model 650 Tone Control Question - by Arran - 07-13-2023, 04:39 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-13-2023, 05:13 PM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-14-2023, 06:05 AM
RE: Model 650 Tone Control Question - by MrFixr55 - 07-14-2023, 06:25 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Vlad95, Thank you for the stringing guides and wow there are so manyosanders0311 — 06:01 PM
5U4 vs 5Z4 tubes
A pre war Hallicrafters, and an early one too, very nice! 1936 is pretty early for metal tubes too, which would explain ...Arran — 05:58 PM
Philco 42-345 Restoration/Repair
Thanks Rod, "When you hear the background hiss and no station it usually indicates that the oscillator quit" ...osanders0311 — 05:52 PM
Philco 42-345 Restoration/Repair
RodB :beerchug:Vlad95 — 10:22 AM
Philco 42-345 Restoration/Repair
Vlad, you nailed it. Swiss and German roots.RodB — 09:54 AM
5U4 vs 5Z4 tubes
Well this is a Hallicrafters SX/9 circa 1936. No real issues so far although I dodged a real bullet with a cap that was...bridkarl — 07:59 AM
5U4 vs 5Z4 tubes
The pinout is the same but the 5U4 has a 3 amp filament, verses 2 amps or less on the 5Z4. I think that the pinout of a ...Arran — 12:04 AM
Philco 42-345 Restoration/Repair
By the way. osanders0311 Take a look here: Dial cord stringing Guides May be here you can fount correct string settin...Vlad95 — 11:15 PM
5U4 vs 5Z4 tubes
5U4 and 5Z4 almost identical. I think nothing happened if you left 5U4 instedad 5Z4 long time. Just heater current 5U4 ...Vlad95 — 11:02 PM
Philco 42-345 Restoration/Repair
Hello Vlad95 , Very Funny ! Sincerely Richardradiorich — 11:01 PM

[-]
Who's Online
There are currently 1254 online users. [Complete List]
» 2 Member(s) | 1252 Guest(s)
AvatarAvatar

>