Triplett 3423 - Defect

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Joined: Sat Apr 07, 2012 3:07 pm

Triplett 3423 - Defect

Post by 845FAN »

Good afternoon

I have a Triplett 3423 tube tester which I have purchased years ago.

The unit was sold to me as recently calibrated and worked without problems for a number of years.

Readings could be compared to other testers of mine, a Sencore 162 as well as a Hickok 600 and a Precise 111, and they made sense most of the time and let me believe the unit was working correctly.

Recently I checked on EF84 pentodes and during warming up I realized that the needle of the meter did no longer reach the line zero position which it would normally reach immediately after switching it on.

Changing the L117 L/M 7GT tube did not help.

I guess one of the elderly parts of this tester like a cap or else has finally given up.

Unfortunately I am not a handy man myself, so I am looking for someone who could check and repair this unit, preferably in the Netherlands, Belgium or Germany.

The Triplett 3423 is otherwise in a good condition and worth repairing, even if it costs a three digit amount of EUR.

Sending it back to the US to someone like Roger Kennedy to look after it is an option of course but very costly, shipment and customs fees alone are probably more than a repair in NL/B or D...

I have the full documentation on this tester available, including the calibration instructions.

The picture gives an idea about how the tester worked in the past.

Thanks for advance for help in this matter.

Best regards


Posts: 2
Joined: Thu Oct 17, 2013 7:48 pm

Re: Triplett 3423 - Defect

Post by Hockik »


Some years ago, I had a Triplett 3423, which was mint condition. I sold it because I felt it was inferior to my Hickok 600 and 752A, but it's me.

As far as I remember, when you switch the 3423 ON, the meter pointer reach more or less the center of the dial, to indicate the LINE CHECK adjustment : right ?

So IMHO if there is a problem here, it is because the LINE CHECK circuit is defective, or the adjustment circuit is, too. Very sorry, I didn't have the documentation nor the schematic of the 3423 in mind, but AFAIR, you would check the resistors and diodes involved in the LINE CHECK display function, and the LINE ADJUSTMENT wirewound pot too, at first. May be you will find the issue there.


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