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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 16th Sep 2017, 1:27 pm   #1
Andy - G8MNM
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Default Testing a Mazda CRM91 CRT?

A few years ago along with the purchase at auction of a BUSH TV22 I also got what appears to be a NOS Mazda CRM91 complete with rubber mask as new!

Whilst I have no immediate use for the tube but would like to know if it is still good.
What is the easiest way to test the tube?


Thanks

Andy
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Old 16th Sep 2017, 3:10 pm   #2
matspar
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Default Re: Testing a Mazda CRM91 CRT?

A CRT tester will tell you if the emission is good and that no internal shorts are present. Without this you are limited a bit. All you can really do is make sure the heater is intact (has continuity) and that there is no continuity between the heater pins and the grid and cathode. Give it a good visual inspection, look for any white cloudy deposits this would suggest loss of vacuum. The only sure fire way to tell is to fit it to a set and get a picture on it!
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Old 16th Sep 2017, 6:14 pm   #3
Andy - G8MNM
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Default Re: Testing a Mazda CRM91 CRT?

Thanks Matspar,

No milky deposits - as is gone to air.

I do have a tube tester but it is of USA origin and still packed away from the move to France almost two years ago.

I can check the heater, but don't have an old enough TV to test it in, the oldest I have is a Bush TV12 which uses a different tube.

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