On Sunday, September 13, 2015 at 4:05:55 PM UTC-4, Balekan wrote:
Well, I had my Triplett 3444 calibrated by Chris Haedt before he passed, God rest his soul. I am now in need of a fresh calibration. Can you folks direct me to who us radio enthusiasts are now trusting with our testers? Any and all help is greatly appreciated!
Mike
Mike:
What makes you think that you need a calibration? There are two very long-lived tubes in that beast (12AU7 & 6C4) that, unless they are seriously worn out, you should experience no drift in calibration for their (reasonable) life.
However, I did look through the manual for that unit (
http://www.triplett..com/wp-content/...2/11/84-96.pdf ) and there is one (1) adjustment for calibration. If you are adept with tubes - implied by owning and using such a tester - and if you have a reasonably accurate VOM (most are, these days), you can do it yourself fairly easily.
In any case, I suggest the following moving forward, and whether you do the calibration yourself or send it out: Once done, pick a couple of basic triode tubes, perhaps an 80 and a 45 (one rectifier and one power tube), or a basic pentode powere tube such as, perhaps, an EL84. Test them. Mark the reading(s) on the tube with a Sharpie. Put these tubes _away_ in a safe place. Every so often, after a few hundred hours of use, re-test the tubes. The reading(s) should be very nearly identical. THESE will become your indicator/test tubes.
I keep a Hickok 539B, and after going through the calibration process, once, I have a 6L6 and an 80 that I tested over twenty (20) years ago. No drift..
On the other hand, if you are anywhere near Kutztown this Friday/Saturday for the big show, bring your tester to the club table, and I would be glad to run through the calibration for you. You MUST let me know before the end of today (Monday) as I will need to cobble up the dummy load required for the test.
Peter Wieck
Melrose Park, PA