GZ34 Test Values

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fado

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GZ34 Test Values
« on: 9 Dec 2016, 11:39 pm »
I was looking at a used GZ34 which was tested on a Funke W19S but I do not know how to interprete the test values.
These are the Funke W19S meter photos provided:




I looks like 55mA is the lowest value in the "good" range and that the tube tested at ~90mA. Someone told me that 55mA on this tester is equal to 60% of a new tube value. If the mA values are linear then 100% would be ~90mA but somehow I doubt that it works that way. I understand that there are many possible uncertainties and errors using the older testers but this is all there is. Thanks for any help on this.

JakeJ

Re: GZ34 Test Values
« Reply #1 on: 10 Dec 2016, 02:39 am »
What is the history of this tube?  BNIB NOS?  Used?  You bought it at a flea market and know nothing of the tube's history?  Based on what you already know about the tester and the values you should get I see no reason to think it isn't ANOS.  Can your tester perform a "life" test?

I have old radio shop pull tubes that test as new because that's how radio shop's survived back in the day.

Jake

FullRangeMan

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Re: GZ34 Test Values
« Reply #2 on: 10 Dec 2016, 05:20 am »
What is the tube brand/manufacturer?
What was the Funke AC supply voltage?
Its 55mA for one plate only or both plates?

The Amperex datasheet say for center values:
Capable of output currents up 250mA(max DC output)
Max peak current per plate 750mA

RCA datasheet say for max design values:
Peak plate current per plate 825mA
Average output current 225mA

If test was properly run this tube looks senile imo.
« Last Edit: 10 Dec 2016, 11:09 am by FullRangeMan »

fado

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Re: GZ34 Test Values
« Reply #3 on: 18 Dec 2016, 03:58 am »
Fullrangeman: Thank You for your response.

The tube was a Philips Miniwatt metal base - looked like the 1954/1955 welded plate version. I assume the Funke W19S would have been 230v. I do not know the answers to your other questions.

fado

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Re: GZ34 Test Values
« Reply #4 on: 18 Dec 2016, 04:11 am »
Jake: Thanks for your input.

The tube was listed on ebay as a used tube. I am aware of the many negative comments about ebay purchases but the few tubes I have purchased from sellers with 100% ratings and have had tested were correctly represented. One I got from a premier non-ebay seller didn't work when I got it and, partly due to my delay, he failed to make good on it.

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