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

40-150 issues
#1

Hello to all,

Working on the next project, a 40-150. Recapped fully, replaced all out of spec resistors, ohmed out the power and output transformers and voice coil, all good. Went to fire it up, no output (ie reception or static) and one of the 41 output tubes overheated. Although I had replaced the coupling cap (#52), I do not have the ability to check for leakage, so I re-replaced with a new cap. #46 to the 7C6 was also replaced.

Pulled the 41s, put in the rectifier tube and went to check voltages. Measure 330V across the 12 mfd electrolytic (#61) as opposed to 270V, and I understand that the new meters do not load a circuit to the degree that the old VTVMs did. Checked across the 16mfd electrolytic and read 286V as opposed to 185V and plate voltages at the 41s was 288V as opposed to 180V. Now, I would presume that the voltages would be higher due to the fact that there is no load, but does this high a voltage seems out of the ordinary?

Wanted to get opinions prior to the next phase of troubleshooting as I really don't want to fry a 41 while I am checking the voltages with the tubes in place. Have already checked all connections I reworked in replacing components against the schematic and my work checks out, so no incorrect connections or cold solder joints.

Thanks for any assistance you may render.

Richard

Schematic here:http://www.nostalgiaair.org/Resources/331/M0013331.htm

Richard


Messages In This Thread
40-150 issues - by RGallahue - 06-16-2012, 11:20 AM
RE: 40-150 issues - by morzh - 06-16-2012, 12:37 PM
RE: 40-150 issues - by RGallahue - 06-16-2012, 02:32 PM
RE: 40-150 issues - by morzh - 06-16-2012, 04:02 PM
RE: 40-150 issues - by RGallahue - 06-16-2012, 06:04 PM
RE: 40-150 issues - by 7estatdef - 06-16-2012, 06:34 PM
RE: 40-150 issues - by morzh - 06-16-2012, 07:53 PM
RE: 40-150 issues - by RGallahue - 06-16-2012, 08:15 PM
RE: 40-150 issues - by morzh - 06-16-2012, 08:31 PM
RE: 40-150 issues - by RGallahue - 06-16-2012, 09:34 PM
RE: 40-150 issues - by morzh - 06-16-2012, 11:05 PM
RE: 40-150 issues - by RGallahue - 06-17-2012, 10:38 AM
RE: 40-150 issues - by morzh - 06-17-2012, 11:27 AM
RE: 40-150 issues - by RGallahue - 06-17-2012, 11:46 AM
RE: 40-150 issues - by morzh - 06-17-2012, 01:47 PM
RE: 40-150 issues - by 7estatdef - 06-17-2012, 02:24 PM
RE: 40-150 issues - by RGallahue - 06-19-2012, 08:12 PM
RE: 40-150 issues - by morzh - 06-20-2012, 05:45 PM
RE: 40-150 issues - by RGallahue - 06-20-2012, 06:16 PM
RE: 40-150 issues - by morzh - 06-21-2012, 10:51 PM
RE: 40-150 issues - by morzh - 06-23-2012, 01:21 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

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

>