L3-3 valve tester repair 

I’ve been working on repairing  a fantastic L3-3 valve tester. It arrived safely, albeit not working the anode regulation circuit. I replaced the pots for either 10T (for grid regulation) and the screen and anode pots (1M). The regulation of the anode isn’t working, so after some time of a frustrating troubleshooting, I decided to open a nice Ale and listen to Herbie Hancock on LP. Happy Friday!

4 Replies to “L3-3 valve tester repair ”

  1. Even new tester when they lie 5-10-15 years have the following problems

    Oxidation of connectors and switches
    Drying of capacitors against time

    Most likely to begin with you need to clean all the switches and connectors in the bathtub and you can manually also have to shoot completely

    Maybe the meter is used not native
    This should be m906
    And it is obligatory with native stamps on screws-
    – he should not have been disassembled


    1. Yes, I knew the amount of work required to restore one hence I wanted to buy one in working condition. That was not the case in fact the seller claimed it was in operational condition. I’ve got some refund back, but not enough to get this fixed by someone else probably. I don’t have the time (or the space in my workshop to work patiently on this tester for a long time).

      I will have to desoldered the rotary switches and clean them properly. Do you know best way of cleaning them?

      Probably best to keep this conversation via email so other subscribers don’t get annoyed with the emails on this specific topic.

      My email is “valves at bartola.co.uk”. If you can please ping me an email would be great.

      The meter is labelled “M24-87 11300” you can see it on the bottom left corner



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