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

Thread Closed

39-30 Refurb
#6

I swapped out the 6A8, 75, 78, and 37 all one at a time, and none really made a difference. Except for the 6A8, but I think that is because it was weak. It cut down on the signal strength all around. I grabbed the 6A8 out of my 38-10 and it acted the same as the other NOS 6A8. So I think that is just confirming when my tester said, the original 6A8 is on it's way out the door.

So I broke out the signal tracer. I checked the plate on the 41, and it sounds like the distortion is still there. Went to the grid on the 41, and it sounds like it was gone. So I grabbed the 41 out of my 39-6 (which was an NOS tube with very low usage on it in my 39-6) and put it in. The behavior was the same. Now, I'm not sure if that's just becasue the signal tracer was amplifying an already amplified signal off the plate. I was pretty sure I had the signal tracer volume low though. I can always check again later. Voltages look good on the 41 - actual (schematic) - plate is 198 (205), Screen 208 (215), Grid -14.5 (not listed, data sheet says -13.5 with 180v plate/screen, so this seems reasonable).

So, any other ideas?


Messages In This Thread
39-30 Refurb - by Nick3092 - 05-13-2015, 10:32 PM
RE: 39-30 Refurb - by Radioroslyn - 05-14-2015, 06:25 AM
RE: 39-30 Refurb - by Nick3092 - 05-14-2015, 09:17 AM
RE: 39-30 Refurb - by morzh - 05-14-2015, 09:53 AM
RE: 39-30 Refurb - by Nick3092 - 05-14-2015, 10:56 AM
RE: 39-30 Refurb - by Nick3092 - 05-14-2015, 06:58 PM
RE: 39-30 Refurb - by Nick3092 - 05-14-2015, 10:58 PM
RE: 39-30 Refurb - by Nick3092 - 05-15-2015, 08:24 AM
RE: 39-30 Refurb - by morzh - 05-15-2015, 01:56 PM
RE: 39-30 Refurb - by Nick3092 - 05-24-2015, 09:33 PM
RE: 39-30 Refurb - by Nick3092 - 07-30-2015, 07:31 PM
RE: 39-30 Refurb - by Radioroslyn - 07-30-2015, 07:52 PM
RE: 39-30 Refurb - by Warren - 07-30-2015, 08:37 PM
RE: 39-30 Refurb - by Nick3092 - 07-31-2015, 08:19 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM

[-]
Who's Online
There are currently 1618 online users. [Complete List]
» 1 Member(s) | 1617 Guest(s)
Avatar

>