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 Post subject: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 2:23 am 
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Joined: Dec Mon 05, 2011 1:10 am
Posts: 352
Many tube testers use #83 rectifier tubes.
RCA APPLICATION NOTE No. 95 , dated August 17, 1938, warns that this tube must be operated in the VERTICAL POSITION ONLY!

UH OH!

If I read the RCA Engineering Bulletin correctly, that means that the trusty (NOT!) TV-7 should be calibrated and operated with its smallest face resting on a horizontal surface. I am working on the design of an optical rotation device to display the meter readings in an ergonometrically correct orientation to minimize neck muscle strain when using this tester in its proper operating position.

The 5Y3 rectifier tube is a tad more forgiving. It can be operated horizontally, provided that its base pins #2 and #7 lie in a horizontal plane.


^^;;^^


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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 5:55 am 
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Joined: Jan Tue 10, 2012 8:39 am
Posts: 819
I wouldn't worry. What they are referring to is when the tube is running hot, say near maximum ratings, the filament may sag in some positions and short to the plate. Perhaps if you run the filament f\voltage on the low side it will be fine.

Many radios and other gear have been run in all positions without trouble. Many years ago I think I did have an incident that blew the tube but maybe it was just a fantasy.


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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 7:27 am 
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Joined: Aug Wed 31, 2011 11:23 pm
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Location: Tucson, AZ
If this was the case then all the Hickok's would not have functioned for many years. If I recall the issue is the mercury needs to vaporize in the bulb before you apply voltage to the rectifier, one reason why you should wait until the rectifier has been on for awhile before testing tubes. Alternative is to use a solid state replacement, the readings are unchanged an no warm up time.

Another issue in changing the position from horizontal to vertical is it can change the meter position because of balance issues of the movement.


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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 12:08 pm 
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Joined: Nov Wed 30, 2016 7:35 pm
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Location: Sunbury, Ohio 43074
You don’t need an optical rotation device. Just fabricate a coupler to connect your tube tester to the washing machine. Set it for spin cycle

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 2:31 pm 
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Location: Columbus Ohio
Many testers use the 83 horizontal, B&K, Hickok.. Both great companies, if their engineers continued to design tester after tester with the 83 like that, doesn't that tell you its ok?
Keep in mind, you will never get a 60 yr old tester to operate at perfection, that was not their design intent at all.

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 2:32 pm 
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Location: Columbus Ohio
Barry H Bennett wrote:
You don’t need an optical rotation device. Just fabricate a coupler to connect your tube tester to the washing machine. Set it for spin cycle


will that throw the 83 out of balance? if one used a solid state 83 you can rinse twice

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 2:39 pm 
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Location: Sunbury, Ohio 43074
I'm not quite sure about the balance thing .... but it should at least keep it dry ;-)

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 11:53 pm 
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Will the earth's magnetic lines of flux affect the meter reading, like they do an oscilloscope trace?

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Mon 10, 2019 11:57 pm 
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Location: Long Island NY
The RCA warning was intended to apply if the tube was operated at its maximum ratings. If operated at full load current for long periods of time, the filaments could sag if they are horizontal. If they sag enough to touch the plates, the tube goes out in a blaze of glory. But in a tube tester, the load is only applied to the 83 intermittently when the Gm test button is pressed, and then it is nowhere near full load current or voltage. So the filaments never develop enough sag to be troublesome.

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 Post subject: Re: Tube Tester Operating Position
PostPosted: Jun Tue 18, 2019 11:45 pm 
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When you fellas come up with mechanical doodad adapters, I get rather agitated and my head starts spinning and get a little off balanced, so I think your Ideas are all washed out, so I keep cycling through everything till everything is dried up in my mind. Getting DIZZY HERE!!!

That's my signal to quit before I start Generating too many Puns!! :mrgreen:

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