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Pilot Model TV-37 3" Television Receiver.

I acquired this TV set from Bert Collins (W6CWC), who was the father of one of my
classmates at Pleasant Hills High School in 1956. I had another receiver just like this one
that had a bad picture tube. I bought this one, since it was working, but did require repairs.
I paid $25 for it.

The very first thing that I did when I got it home was to take it apart and see if I could fix
it. It had a bad picture tearing and horizontal sync problem. I used one of my mothers
table knives to remove the screws with instead of a screw driver.
When I was examining the set, I turned it right
side up, right on top of the table knife. The knife flipped up inside the chassis, there
was a blue flash and a sputtering noise. Wouldn't you know it, it shorted the high side of the
filament string and burnt out the picture tube along with a couple of other tubes as well. I
was devastated to say the least. Finding another picture tube was almost impossible. I
did find a 3" CRT that had a green phosphor that worked in the TV, although viewing a
green and black picture wasn't very satisfying. I put the TV aside having failed to repair
the original problem.

I always kept my eyes open at the various swap meets for a black and white picture tube.
(3KP4). About 15 years ago I went to a swap meet where someone had a brand new one
for sale, I gladly purchased for $50. After purchasing the new picture tube, I fired up
the TV set and found out it developed more problems over the years and wouldn't work at all.
The TV was put aside again and I was saving it for a retirement project.

In February 2005 I took it out of storage and for about 4 frustrating days, restored the TV
set to perfect working order and installed the brand new picture tube.

All in all the TV set had about 7 simultaneous problems that developed over the years.
Every electrolytic capacitor and paper capacitor in the set was bad along with nearly a
dozen resistors that had changed value plus several tubes were shorted. Once all of this
was fixed, it was back to the original problem that was in the set when I acquired
it some 49 years ago.

This set had been worked on by several people before I bought it. There were two major
problems left to fix. The first was the picture tearing. Someone had clipped a grid
resistor loose in the sync circuit and reconnected it to the filament string of another stage.
When the resistor was placed back where it was supposed to be, the TV worked normally
The next problem was intermittent picture and sound.
This problem drove me nuts! Touching anything on the chassis would either kill the
picture or restore it. I was finally able to trace the problem back to the tuner with an
oscilloscope. In a moment of shear joy, I found the problem to be simply a loose ground clip to
the local oscillator trimmer capacitor located in the tuner. Someone backed it off for
reasons unknown. Finally the receiver was completely fixed!

Here are the details of the receiver:

Price in 1946, $99.99

21 tubes, including the picture tube. Tubes arranged in two series strings, no power transformer. (A.C./D.C.)

Variable tuning tuner covers 2 bands. Band 1 covers channel 2 thru 6. Band 2 covers
channel 7 thru 13. Receiver will also pick FM broadcast stations, an undocumented feature.

Has 21Mhz video IF amplifier and a 21Mhz ratio detector for the sound.

Set has a 5" electro-dynamic wound field speaker, and only a 3" picture.

Dimensions are 15"W 16"D & 10" high.

Weight about 10#

Cabinet is made of painted Masonite and wood.

The TV set has a bare minimum of components, but was well engineered in its time.

 

In conclusion this retirement project was the most frustrating restoration job that
I've ever tackled, even though the project only took 4 days.

Dan K6PRK