I picked up a fully loaded Zenith Chancellor roundy combo

[old_tv_nut]

Originally Posted by consoleguy67

As far as the clover leaf assembly; has anyone had luck reproducing them on a 3d printer?

There has been chatter about that, but no one seems to have taken the challenge. I would certainly pay for one if they became available.

[DavGoodlin]

I have been told by some younger techs that an .stl file coulc be developed on that assembly, literally a 3D CADD file the printer needs to reproduce it.

[Electronic M]

Well the new better replacement picture tube is in and I've got good purity and static convergence.
Now I can start trying to restore the chassis in earnest.
I was able to get audio for the first time by wiggling tubes, but it's weak so I have more to do there.
I'm happy with where I'm re-starting from.

[AlanInSitges]

I love these big old roundies, especially Zeniths, especially especially with their TOTL hifi thrown in. I would wager I'm nearly as excited about this one as you are. Lots of pics as you go through the process please!

[Electronic M]

Anyone happen to have a picture of the power switch and remote chassis power harness plugged into a 25MC chassis the switch and remote harness are hacked up enough that they don't make anymore... I'd like to fix it such that it looks atleast somewhat like factory work.

[damen]

This is a 25MC46. The plastic Molex housing has a tab that snaps into a rectangular hole in the chassis.

[damen]

chassis

[Electronic M]

Originally Posted by damen

This is a 25MC46. The plastic Molex housing has a tab that snaps into a rectangular hole in the chassis.

Thanks! This helps me greatly.

I was able to dig up some pictures of the connector on chassis on older L line sets but none as clear as yours. Seeing that 2 of the wires from the molex have connectors that plug onto the chassis terminals and the third (looks like the black) wire runs under chassis gives me a good idea of how I should rebuild mine.

[Electronic M]

So here's how it turned out.
Before and after.


The red wire is a stand in for the front panel power switch.

I also cleaned up the audio output transformer replacement someone made. The transformer is a Zenith part but not the right part number so I have to look into that....My best guess is the pirated the one from the old K line chassis when they Frankensteined the M line in.


There's something frustrating about seeing a transformer where they bothered to solder the speaker leads but only mounted one of the 2 mounting tabs of the transformer (in the wrong place) because they didn't cut the primary leads long enough to reach and wanted to use wire nuts on the primary..... It's like whoever did the work was saying "I CAN do this right, but I'm too lazy to bother following through".

Last night before I built up the power switch I got the remote chassis working. Which consisted of oiling moving parts, making one good remote out of 2 damaged ones, and running everything through it's paces.

Since this console was a frankenset before I got it I seriously considering making the remote opperate the stereo when the TV is off... It's going to take some engineering, but I think the remote chassis design lends it's self to doing this. This idea is going to be down the road a ways. I need to verify the TV works correctly and get the stereo working perfect first. Once I have the kinks out then I'll be comfortable upgrading it from a stable base.

[Electronic M]

Well my franken-chancellor is alive for Halloween.


So I changed all the ceramic Elmenco caps in the vertical and the weird non-linearity persists. I'm going to check vertical tubes and look at the couplates and lytics in the vertical next.

Anyone else have an issue where the yoke centering rings move but don't seem to have any effect?

I also cleaned up the HV cage too. I decided to silicone the mouse chew on 2 of the wires. And I installed a solid state focus rectifier (the original Zenith focus tube was dead) leaving the original tube to act as a decoration.

[Electronic M]

So I think I found the vertical problem. K2 the vertical feedback network which is supposed to test 90K ohms tested over 2M. I also changed 3-4 off tolerance resistors, and checked the lyrics on my Heathkit C3.
Before I verify my work I need to hunt down an issue where after 15 minutes the audio gets distorted.

I have one more issue to address. Because this is a K line CRT mount Frankensteined to an M line TV the chassis is designed for degaussing, but the cabinet lacks degaussing coils.
Can I use the spare degaussing coils from a 25" CCII or a 23" 20BC50 with the 25MC43 chassis or do I need an M line degaussing coil?

[kvflyer]

Originally Posted by Electronic M

So ...
Before I verify my work I need to hunt down an issue where after 15 minutes the audio gets distorted.

...

Surely you have considered grid emission of the output tube? However... that is usually with tubes in radios which have a very high filament voltage, like a 50C5 etc. But not unheard of with other "output" tubes.

Hope you "Gitter Going".

[Electronic M]

Originally Posted by kvflyer

Surely you have considered grid emission of the output tube? However... that is usually with tubes in radios which have a very high filament voltage, like a 50C5 etc. But not unheard of with other "output" tubes.

Hope you "Gitter Going".

Lol.

I had the most frustration yesterday with the vertical. A spade connector in the yoke bent in a way that made it so there was lousy connection and barley any deflection and I wasted a lot of time troubleshooting my replacement K networks (K1 which still tested good went back in). But it now works about perfect (besides the centering rings being dead).

I changed a few off tolerance resistors in the audio but didn't find anything terrible. The tubes on the other hand....All 3 audio tubes had issues. The original Zenith branded 6KT8 and 6BQ5 were both testing bad and the 6BN6 had a short in it. All 3 got swapped and after an hour I did have more buzz on scenes with a lot of white. I got about %95 of that adjusted out by tweaking the buzz control and dialing back the AGC (the AGC did the most).

Some of my lytics are getting warm and I'm thinking about changing them.

[Electronic M]

It's complete. I'll post some resto photos and explanation soon, but check out the finished product.
https://m.youtube.com/watch?v=8IYZDpPr_xc

It's everything I expected it to be when I bought it and so much more.

[etype2]

Very nice.