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

Philco 37-670 restoration thread
#22

Well, after taking out the RF section, replacing some caps and putting the set back together, all H**l has broken loose. Prior to taking out the floating RF, I was getting great reception and volume across all bands. Now, I am getting very weak AM volume and somewhat decent volume (though there's a lot of squealing going on) on the other bands. In AM, I can barely hear it with volume turned all the way up.
When I squeeze the 6A8 Dector/oscillator grid cap wire, the volume increases a good bit. In SW bands, it's very loud, just about what it was before, I think. In AM, its loud though not as loud as it was prior to pulling out the RF section. When I let go of the grid cap wire, the volume dies again. Reception is poor on AM; on the shortwave bands, there is some reception; however there's also a ton of squealing. The 6A8 voltages are pretty much where they should be. Tubes all test good.
Can someone guide me through some troubleshooting? I would love to solve these issues. It's a beautiful set and I'm very discouraged. Could use some expert help.

Thank you.

Here's a clean copy of the schematic. Click on the photo once or twice to zoom all the way in.

http://imgur.com/NozIIBg


Messages In This Thread
Philco 37-670 restoration thread - by Diverted - 12-30-2014, 03:55 PM
RE: Philco 37-670 rectifier - by millievolt - 12-30-2014, 04:25 PM
RE: Philco 37-670 rectifier - by Diverted - 12-30-2014, 05:03 PM
RE: Philco 37-670 rectifier - by Chuck Schwark - 12-30-2014, 04:28 PM
RE: Philco 37-670 rectifier - by millievolt - 12-30-2014, 04:33 PM
RE: Philco 37-670 rectifier - by morzh - 12-30-2014, 06:27 PM
RE: Philco 37-670 rectifier - by Diverted - 12-30-2014, 07:45 PM
RE: Philco 37-670 rectifier - by OZ4 - 12-30-2014, 08:14 PM
RE: Philco 37-670 rectifier - by Diverted - 12-30-2014, 08:35 PM
RE: Philco 37-670 rectifier - by OZ4 - 12-30-2014, 09:10 PM
RE: Philco 37-670 rectifier - by thirtiesradio - 12-31-2014, 03:44 AM
RE: Philco 37-670 rectifier - by Arran - 12-31-2014, 04:54 AM
RE: Philco 37-670 rectifier - by Diverted - 12-31-2014, 09:03 AM
RE: Philco 37-670 restoration thread - by John R - 12-31-2014, 05:19 PM
RE: Philco 37-670 restoration thread - by OZ4 - 12-31-2014, 01:03 PM
RE: Philco 37-670 restoration thread - by Diverted - 02-03-2015, 12:11 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Rogers Majestic R-646
Vlad; I was just reminded of something else, I'm not sure why but many Rogers built sets do seem to have open primari...Arran — 04:40 PM
Rogers Majestic R-646
Thanks RpdB I don't think there's much difference with interstage transformers of different models other than dimersion...Vlad95 — 03:27 PM
Rogers Majestic R-646
Vlad; I looks like your set has the same problem that mine did, both a bad output transformer, and a bad audio inters...Arran — 03:21 PM
Rogers Majestic R-646
Ouch! Not often the secondary takes a hit. Wish there was a better solution. I have a good interstage transformer but it...RodB — 02:59 PM
Rogers Majestic R-646
By the way, the bypass you suggested is a rare solution in some circuits. For example, this schematics solution is used...Vlad95 — 01:43 PM
Rogers Majestic R-646
No, you are wrong, because you did not know the details. Unfortunately, only ONE winding out of six is intact in both t...Vlad95 — 01:14 PM
Rogers Majestic R-646
The output 45s are still in push-pull because the transformer secondary winding is still in the grid circuit providing o...RodB — 11:52 AM
Rogers Majestic R-646
Thanks RodB for the help. But this is not a real solution to this situation, not even a temporary one. Because the firs...Vlad95 — 11:34 AM
Philco Model 16 wiring question
I was going to check the voltages as you suggested and hooked it up to my dim bulb. It appears I have a short. The bul...bobclausen — 10:34 AM
Rogers Majestic R-646
You can bypass the interstage transformer by disconnecting the primary, connect a load resistor of about 10k - 20k to th...RodB — 09:40 AM

[-]
Who's Online
There are currently 1003 online users. [Complete List]
» 3 Member(s) | 1000 Guest(s)
AvatarAvatarAvatar

>