Bush TV24C

[LENINGRAD T2]

This amateur TV that I am writing about is an interesting specimen. It is a prototype model built in 1947. This TV set is now in the museum and is considered the first Polish post-war set. At my request, the Museum sent me interesting photos of the receiver's interior, which had not been published anywhere. I will not elaborate on it now. The selenium rectifier and the characteristic red EF50 pentodes are eye-catching. So this forum will be a good place to present this TV. I am waiting for permission to publish the photos. The designers of the TV set had good contacts with Pye and Marconi even before the war.

It is interesting that the technology in the 40's allowed the production of high voltage transformers for home applications, such as the Pye B16T.

[ppppenguin]

It is interesting that the technology in the 40's allowed the production of high voltage transformers for home applications, such as the Pye B16T.

All pre-war sets also had a high voltage transformer.

[Ed_Dinning]

Hi, most countries had transformers on their grid systems at in excess of 100Kv before the start of the war; this also gave an impetus to develop better insulation systems

Ed

[LENINGRAD T2]

Before the war, TV users probably did not realize the danger posed by these receivers or believed that a distance of 2-3 meters was safe. In any case, the warning on the TV casing - high voltage - did not deter. The "threat" was enclosed in a wooden case. After the war, experiments with cable television were carried out in Moscow. Very simple receivers with an oscilloscope tube were manufactured. All the necessary voltages were supplied from the wall outlet, including the power supply to the CRT. Users could no longer accept such a solution. I guess right. The project failed.

[Murphyv310]

Hi.
Yesterday I recapped the receiver along with any wildly out of spec resistors. Today I replaced any perished cables, replaced the 0.75uf hum bucking cap with 2 x  1.5uf motor run caps in series with balancing resistors added. Fitted all back and getting very good results, the CRT though needs rotating as the picture isn't level, I don't want to force the scan coils.
Just some cabinet work to do.

[ppppenguin]

Very nice results indeed.

[LENINGRAD T2]

I will go back to the beginning now. Do you protect any elements when washing the chassis, e.g. coils, transformers?
Until now, when I thought about TV Bush, I was thinking about the cult TV22. Your model also has SOMETHING in it. This is, of course, the opinion of an outsider. Do you have Trevor your favorite model from the 405 line era?

[Murphyv310]

Hi Adam.
I don't protect the transformers, the cleaning takes less than a minute and I don't deliberately aim the lance at components. The idea is to brush Traffic Film Remover on the chassis, leave it for a couple of minutes then quickly rinse with the pressure washer. The key is the drying process. I have a dehumidifier in the shed and an under bench heater. A small 1kw fan heater blows warm air over the full chassis and its usually dry within an hour. A compressor and an air blower gun is very useful too.
I've washed full colour TV printed boards that are covered in filth from cigarette smokers this way and have never had any issues. It's sensible drying, blowing the worst off with an airline and then a sustained warm air stream that dries the residue out.

My favourite TV was the first set I looked at as an apprentice in 1970, a Murphy V310 from 1958. My brilliant V310 is with a collector in Cramlington, I do have the V330 which has an FM radio inbuilt using the sets tuner, plus it is a double conversion superhet.

[Murphyv310]

Hi.
I've been running the set on test today. Its had a good couple of hours soak.
No real issues just a slight reduction of width after around an hour but it stabilises thereafter, there is a little false triggering on line that clears with careful adjustment of the line hold but brightness level changes can bring it back. It could be EHT smoothing or an issue in the LOPT, not so sure yet but I'll look at that issue at some other time as its not hugely bad. Overall very happy with the results.

https://youtu.be/tUCp-_LqG54.

[LENINGRAD T2]

effective resuscitation