The Hickok 750 tube tester is a Mutual Conductance tube tester. Mutual Conductance tube testers are the best for true vacuum tube performance. When matching tubes, this is the best type of tester to use.
I replaced the meter movement on this tester. The original meter movement developed a mechanical problem. The needle came unglued from the movement coil. I made a quick fix and got it going for the short term.
Assessment
This tube tester is in pretty good shape. A lot of the old Hickok tube testers were work horses and were used daily. This resulted in a lot of wear on most of them. The case on this particular unit is not too badly beat up. There are a few nicks and scratches; overall the tester is in good condition.
Calibration
There is no calibration procedure available for the 750, but several other models of Hickok tube testers are very similar and I had to develop a calibration procedure from those other testers. I calibrated this tube tester using what information was available. The shorts testing circuitry was pretty far off. Most every tube I tested before calibration showed a short. It now works properly following the calibration.
What I particularly like about this tester is that I can check for overall tube quality and also check Mutual Conductance.
Comparison to Emission Tester
I have found a lot of tubes that will check good on an emission tester will test bad on the 750.
Hickok tube testers command a premium price these days, and overall this Hickok 750 tube tester is a nice tube tester and well worth the investment.
Contact me if you have a tube tester you want calibrated.
just wondering if you have an updated data file for checking “newer” tubes such as kt88’s 6bq5 etc.
if so can you contact me at jeremy@birthdayboysmusic.com
The latest tube testing data I have is the Hickok 750 roll chart that came with the tester. I don’t know of any other data available. The KT88 should test with 6550 settings, but I don’t see any settings for the 6550 in the 750 roll chart. The 6BQ5 is in the roll chart I have.
how much are you asking for this tester?
This tester is not for sale. I no longer own it.