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 Post subject: Hickok "percent quality"
PostPosted: Mar Tue 27, 2012 8:54 pm 
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Joined: Mar Tue 27, 2012 8:52 pm
Posts: 3
Hi, I recently started using a Hickok TV-2. Is there any way to convert "percent quality" into microhmos, which is more of a standard way of representing Gm?

Thanks!


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 Post subject: Re: Hickok "percent quality"
PostPosted: Mar Thu 29, 2012 4:09 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7005
Location: Latham NY
In the Field and Depot Maintenance manual it states the meter is calibrated directly in percent quality of the rated mutual conductance. The actual value of the Gm can be obtained by multiplying the value indicated in % times the rated value of the Gm of the tube in a manual.

Gm= percent quality x rated value of Gm
-------------------
100

You would look up the Gm in a tube manual. I find it very convenient to know the % quality related to 100% being a new tube to make a judgement of the tubes worth. The actual Gm number is not important to me, just the % the tube being tested is what I want to know. This is different from the TV-7 readings which are more vague.


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 Post subject: Re: Hickok "percent quality"
PostPosted: Mar Thu 29, 2012 4:34 pm 
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Joined: Oct Sat 20, 2007 3:36 am
Posts: 13596
Location: New Hampshire
Quote:
This is different from the TV-7 readings which are more vague.


Which seems to be the standard of audiophools and some others on Fleabay.

Realize of course that the tube manual Gm is strictly a bogey target and the actual NOS tube can be off 10-20% depending upon production run and manufacturer and it was real bad near the end especially with RCA.

Carl


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 Post subject: Re: Hickok "percent quality"
PostPosted: Mar Fri 30, 2012 1:22 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 23530
Location: Pocasset, Cape Cod, MA
Attachment:
TV2.jpg
TV2.jpg [ 33.08 KiB | Viewed 179 times ]
(from "Tube Testers and Classic Electronic Test Gear")


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 Post subject: Re: Hickok "percent quality"
PostPosted: Mar Fri 30, 2012 5:20 pm 
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Joined: Mar Tue 27, 2012 8:52 pm
Posts: 3
Thanks everyone! Very enlightening...


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