Strange resistance reading prior to C4S install

sharktopus · 773

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Offline sharktopus

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on: March 14, 2021, 02:45:34 PM
I was double checking all of my resistances before installing the c4s.  Everything was fine except the reading on terminal 3 reads overlimit on my meter instead of 880 ohms.  I reflowed all the joints connected to it, and also swapped tubes to no avail.  I have my notes from the initial build and it had measured 884.  Any ideas for what to try next?

Drew Sanford


Offline Paul Birkeland

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Reply #1 on: March 14, 2021, 03:21:48 PM
What resistance do you see at terminal 11?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline sharktopus

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Reply #2 on: March 14, 2021, 03:40:04 PM
Terminal 11 reads 672 ohms.

Drew Sanford


Offline Paul Birkeland

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Reply #3 on: March 14, 2021, 04:11:54 PM
How about terminals 10 and 5 on the OT-2 on that side?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline sharktopus

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Reply #4 on: March 16, 2021, 09:53:36 AM
Terminal 5 also reads as over limit.  Terminal 10 reads as 672 ohms.

Drew Sanford


Offline Paul Birkeland

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Reply #5 on: March 16, 2021, 09:54:33 AM
Put one meter probe on terminal 5 on the OT-2 and the other probe on terminal 10 of the OT-2, what resistance do you see there?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline sharktopus

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Reply #6 on: March 16, 2021, 02:40:33 PM
I get over limit between those two.  I also get the same between terminal 5 and every other terminal on the OT-2.

Drew Sanford


Offline Paul Birkeland

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Reply #7 on: March 16, 2021, 03:03:39 PM
Try 5 and 10 on the other OT-2.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline sharktopus

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Reply #8 on: March 16, 2021, 04:18:08 PM
Between those reads 211 ohms

Drew Sanford


Offline Paul Birkeland

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Reply #9 on: March 16, 2021, 04:21:38 PM
You may have a broken wire on your OT-2 that isn't giving a reading between 5 and 10.  If those lugs get pulled too hard, the wire can break where it leaves the tab and goes into the transformer.  This is generally pretty visible and often can be repaired pretty easily. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man