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SoundMods
PostPosted: March 30th, 2025, 1:25 pm 
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Being a user of the 845 directly-heated power-triode it is been frustrating that most if not all tube testers are not fitted with the "jumbo" tube socket.

That issue has now been eliminated with a jumbo-socket adapter that recently came on the market. Here is the link:

https://www.ebay.com/itm/355472580407

The information provided only has settings for two tube testers; however, any tube tester that has standard 4-pin sockets for the likes of 300Bs can be setup with a little fiddling.

I started with the 300B settings for pin-out then set about establishing settings for sensitivity, load, etc.

I used a known 845 as a benchmark and can now test my own 845s for viability and especially for matching pairs.


Attachments:
845 Test Adapter.jpg
845 Test Adapter.jpg [ 618.8 KiB | Viewed 14895 times ]

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Grover Gardner
PostPosted: March 31st, 2025, 12:35 am 
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Joined: June 4th, 2013, 2:39 pm
Posts: 502
SoundMods wrote:
Being a user of the 845 directly-heated power-triode it is been frustrating that most if not all tube testers are not fitted with the "jumbo" tube socket.

That issue has now been eliminated with a jumbo-socket adapter that recently came on the market. Here is the link:

https://www.ebay.com/itm/355472580407

The information provided only has settings for two tube testers; however, any tube tester that has standard 4-pin sockets for the likes of 300Bs can be setup with a little fiddling.

I started with the 300B settings for pin-out then set about establishing settings for sensitivity, load, etc.

I used a known 845 as a benchmark and can now test my own 845s for viability and especially for matching pairs.


10 volts at 3.5A filament supply is pretty tough for any tube tester in my collection.
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SoundMods
PostPosted: March 31st, 2025, 10:08 am 
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Location: Parkville, Maryland
Grover Gardner wrote:
10 volts at 3.5A filament supply is pretty tough for any tube tester in my collection.

I also thought so. Yet the reality is that it is no problem. My tester fuses out at 1-amp. @ 120-vac. (120-VA)

10-volts @ 3.5-amps. is only 35-VA. My tester does not have a 10-volt setting, but the 845 works pretty well with 7.5-volts for the purpose of testing.

I was "chicken" to try the next setting of 12.5-volts on a perfectly good tube.

Anyhow I was able to test a couple of tubes with no issues. The adapter ROCKS! :thumbup:

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David McGown
PostPosted: March 31st, 2025, 11:12 am 
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https://www.youtube.com/watch?v=4Y2fj11fzWM
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SoundMods
PostPosted: March 31st, 2025, 11:27 am 
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David McGown wrote:
https://www.youtube.com/watch?v=4Y2fj11fzWM

YIKES!! That's akin to asking what time is it and having to sit through a lecture on how a watch works.

The adapter satisfies the K.I.S.S. method.

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