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

Thread Closed

40-155 transformer output
#5

Replaced the tubes. Powers up with about 40 watts usage. Zero audio. Going to start working backwards from the speaker. I’m starting with the assumption the audio transformer has an issue so I’ll use my ohmmeter and check the windings.
 Update 10/11

Spent about five hours today on this. Mostly
replacing bad rubber wiring. The wiring on the speaker was bad so replaced that. Also the audio transformer showed short so replaced that. General check of work to date, reflowing soldering, checking wires in right places.
Current status is it powers up. No audio except a very low hum. Volume and tone controls modify this hum so these circuits apparently work. 
Caps all replaced. Waiting on resistors to start checking and replacement.
Have an unmodified unit side by side on bench so that’s helpful. 
Bad volume control?? It’s been replaced at some point with this small random switched pot. Soneone just threw in a part.  Replacing with 2 megaohm linear Allen-Bradley pot so this is correct per schematic. 
Mostly cleanup work today. Making sure power supply caps are properly mounted and not just hanging in space.


Attached Files Image(s)
   


Messages In This Thread
40-155 transformer output - by bridkarl - 10-04-2025, 04:41 PM
RE: 40-155 transformer output - by MrFixr55 - 10-05-2025, 12:23 AM
RE: 40-155 transformer output - by bridkarl - 10-05-2025, 01:21 AM
RE: 40-155 transformer output - by morzh - 10-05-2025, 01:57 PM
RE: 40-155 transformer output - by bridkarl - 10-09-2025, 11:03 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
hello david, I have a similar generator in my collection that features a cast iron, single-cylinder Briggs & Stratt...radiorich — 01:00 AM
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Try looking at this site the book mark is for a old generator that I was given. David    https://radionerds.com/index.ph...David — 08:36 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Hello Everyone, I am looking for voltage identification for all the pin positions on the socket of a CRV-20130 power su...Tonym4704 — 08:16 PM
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
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

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

>