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 Post subject: TV-7 D/U Shorts Testing Problem
PostPosted: Aug Tue 17, 2010 8:23 pm 
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Location: Wilmington, NC 28412 USA
I tested some 6BQ5 tubes on my TV-7 D/U and they ALL check shorted.

Shorts light glows in all positions except 4

Did the Shorts check in the Manual TM 11-6625-274-35
Chapter 3 Page 40-41

All test results are as expected with the 100K and 510K resistors.

I checked these tubes on a recently acquired Knight 600B and they have all 6BQ5 testing with 0 Emissions.
Looks like I have 2 faulty tube testers.
I also have a Jackson 103 , but no listing for the 6BQ5

I think I am being punished for selling off my Hickok 600A.

Has anyone else had this problem with the TV-7 D/U ???

Bob T.


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 Post subject:
PostPosted: Aug Tue 17, 2010 9:16 pm 
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Location: Stafford, Texas USA
Bob

Some time the routeing of the power cord will cause shorts on tubes that are checked in the 9 pin socket on A TV-7D/U after the unit is put back in the box.



Jimmie


Last edited by Jimmie Stewart on Aug Wed 18, 2010 3:52 am, edited 1 time in total.

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 Post subject:
PostPosted: Aug Tue 17, 2010 11:16 pm 
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Jimmie Stewart wrote:
Bob

Some time the routeing of the power cord will cause shorts on tubes that are checked in the 9 pin socket on A TV-7D/U after the unit is put back in the box.

My 6BQ5's test fine on my TV-7 D/U.

Jimmie


Not much room, there no choice but to route cord same as original.
I did put a new grounded Cord assembly on mine. But it is routed the exact same route as the original.

For sure I will take it apart and see if it makes any difference.

I almost threw 2 good 6BQ5's in the trash.

Found this old post ??????


http://www.antiqueradios.com/forums/vie ... 0837cb79e2

Bob T.


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 Post subject:
PostPosted: Aug Tue 17, 2010 11:51 pm 
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Location: Wilmington, NC 28412 USA
Pulled out the updated tube listings that Nolan Lee was so kind and wonderful to supply to the world

Surenuff It is Normal for what I am getting.

His listing for the 6BQ5

SHOWS SHORT ON 1-2-3 AND 5 Reference Air Force Supplement T.O. 33AA21-5-31G

Looks like I will be using Nolan"s settings all the time.
He is more accurate than what is in the TV-7 booklet


Bob T.


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 Post subject:
PostPosted: Aug Wed 18, 2010 4:32 am 
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Location: Stafford, Texas USA
Tonight after look at my notes on TV-7’s I see that they have problems test all tube that have a 9CV basing, with pins 1,6, and 8 have internal connection.
Jimmie


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 Post subject:
PostPosted: Aug Thu 19, 2010 9:19 am 
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Location: Pittsburgh PA
Yeah that was my old post. The short indication is normal, so you don't want to test EL84's in the TV7's unless the EL84 has been already verified to be without shorts. TV-7's DO NOT have a bias fuse bulb. If you think the tube is just indicating a shorted condition because "that is normal for the tv7's" and the tube is *really* shorted, you could smoke a very expensive bias pot since it doesn't have a fuse bulb in series with it. OUCH!

I use my 752 to test el84's with.

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