Heathkit TT-1A Calibration

[sanford1]

Does anyone here know the calibration procedure for the Heathkit TT-1A tube tester? I have all the manuals *except* the assembly manual, which I suppose, includes it. I'm going to replace the electrolytics today and would like to try and get it back in spec.

Thanks and Happy New Year!

Gary Sanford

 

[Geek]

Hi,

Did you try here yet?
http://bama.sbc.edu/heath.htm

 

[sanford1]

Sure did. Bama has the ops manual and tube data but not the assembly manual that has the cal procedure.

 

[Geek]

Dang!

What I would do is take several tubes to a buddy who had a known good tester, write down the results and use those to calibrate it 🙂

An assortment like a couple of low gm tubes, a couple of high, power pentodes and a diode or two.

 

[sanford1]

This is a pretty neat tester as it has a self calibration feature. Inside, there is a 4 position rotary switch labeled "bias, signal, meter and operate". There are 3 pots that refer to the first 3 positions and are adjusted using the meter and the front panel settings.

These compare well against the best Hickoks and were offered as kits explaining the self-cal procedure. I have all the manuals in hard copy except the assembly manual that includes the cal data. When I opened it up to recap it I found an "Inspected By" stamp inside, so maybe it was factory assembled and didn't include the service data.😕

An example is up on Ebay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25422&item=3862911922&rd=1
Nice tester...