Zenith G2951R Stratosphere

[bandersen]

A customer dropped off this lovely 1949/50 Zenith G2951R Stratosphere for restoration last year.
Yes, Zenith made a "Strat" TV not to be confused with their famous radio of the same name.
I want to get to it while this chassis is fresh in my mind.
Last of my Zenith porthole project for now.
I prefer this earlier design as it is more robust and over engineered compared to later models.
Hefty power transformer with dual 5U4s and dual 6BG6 horizontal output tubes running in parallel.
16" metal cone 16EP4 CRT.










Rebuilt CRT installed sometime in the 1950s. I can't make out the last digit.


I've used this tester for years and know it's on the conservative side. It will produce a good image. Darn near impossible to find a replacement.

[bandersen]

I figure it's a good sign when all the chassis bolts are present. No so much the pile of white powder under the power supply.


Sure enough, one of the caps has vented.


Remember to unmount the picture control switch before pulling the chassis or you will be very sorry.


Upper chassis has some minor issues. One of the IF cans has its cover knock off and the fine tuning cord is broken.




\

Looks to be all original under the hood.

[bandersen]

Time to get to work. Quite similar to the 12" blonde Zenith I started on last year so no surprises.
Ooodles of "bumblee" type paper caps and open sand coated power resistors.
Also, a few paper caps masquerading as micas.







I'll carefully work on it with the CRT installed as it's a hassle to unmount and reinstall.

[Electronic M]

Nice TV.

On the subject of Stratosphere radio adjacent Zenith's. Around that time Zenith had a radio-phono (AM and 78 RPM Cobra) that had the same stag covering and door latch as a transoceanic. I've been looking for one for a while.

[bandersen]

It lives! No raster at first then I noticed a lightshow inside the 1B3 rectifier. Replacing that resulted in a dim raster.
HV/EHT a bit low at only 10kV and no reception but it's early days.
Next, I'll go through and test all the tubes. A number appear to be the originals and I expect some are weak.

[kvflyer]

Great news!

[bandersen]

Well that was an easy fix. I missed a wire when replacing the filter cap on the horizontal oscillator plate resistor.


Getting back to the tuner, I discovered the plate load resistor was open. Seen this many times before.

[electronjohn]

Yay!

[bandersen]

I reinstalled the 16EP4 CRT and made some final adjustments.
I had to clean the antenna terminals and solidly tighten down my signal feed to eliminate all the interference.




The camera in my phone is rather sensitive to ambient lighting. Here it is looking more like a proper B&W image.