Restoring a 46-1226 Code 125
Posts: 348
Threads: 48
Joined: Oct 2013
City: Tioga, Texas, USA
In the course of checking some voltages in the radio chassis, I discovered that the AGC voltage goes to about +12VDC which is not necessarily what I was expecting. The grid bias at the output tubes signal grids are at -19.9VDC. That does not change during warm-up but after about two minutes the audio comes up. I also discovered by measuring the voltages on the cathode resistors of the IF tubes that the 1st IF appears to rise to beyond 8VDC and goes all the way to +131 volts after a while! The 68 ohm cathode resistor measured about 72 ohms and since the voltage there was so high, I decided to replace it with another 68 ohm resistor. That resistor performed the same way and also wound up measuring about 70 ohms or more after cycling one time with the +131volts showing up on the cathode circuit. The tube checks OK on the tube tester and has good emission. I suspect the tube socket is defective and has a B+ internal bridge in it.
So it appears I need to order some Loctal sockets. These will not be easy to change. I am thinking about changing this one to a conventional Octal socket and replacing the 1st IF tube with a suitable Octal base tube. I never saw any real advantage to Loctal tubes and sockets.
Joe
Messages In This Thread
RE: Restoring a 46-1226 Code 125 - by Joeztech - 01-22-2018, 03:08 PM
Users browsing this thread: 2 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 2364 online users. [Complete List] » 1 Member(s) | 2363 Guest(s)
|
|
|
|

|