Decades ago, I inherited a Heathkit TC-3 tube checker.

Recently, I dusted it off, as I'm trying to being my old TVs and radios up to spec during the winter.

The tester came with two scrolls showing the tube tester settings for testing the types of tubes then in common use (one scroll is from about 1960, and is missing a lot of newer tubes, the other from about 1966, and some of the older tubes are dropped from the list), but there is no instruction manual with it.

The reason I'm writing this is that the tube data scrolls do not fully explain how to test the tubes. Most confusing to me, is that the lever settings are printed in two typefaces, mostly a regular serif font, but at least one lever, usually set to the bottom, being in a bold sans serif font. In some cases, parentheses get involved.

For example:
The settings for the type 6CL6 are:

3 6.3 22 (BJ)(CH) FG................AD.

Now, the first three figures are self-explanatory, but I'm lost on the difference between, say, A and A, and the difference between (CH) and merely CH.

As before, thanks in advance for any information about using the TC-3.

Decades ago, I inherited a Heathkit TC-3 tube checker.

Recently, I dusted it off, as I'm trying to being my old TVs and radios up to spec during the winter.

The tester came with two scrolls showing the tube tester settings for testing the types of tubes then in common use (one scroll is from about 1960, and is missing a lot of newer tubes, the other from about 1966, and some of the older tubes are dropped from the list), but there is no instruction manual with it.

The reason I'm writing this is that the tube data scrolls do not fully explain how to test the tubes. Most confusing to me, is that the lever settings are printed in two typefaces, mostly a regular serif font, but at least one lever, usually set to the bottom, being in a bold sans serif font. In some cases, parentheses get involved.

For example:
The settings for the type 6CL6 are:

3 6.3 22 (BJ)(CH) FG................AD.

Now, the first three figures are self-explanatory, but I'm lost on the difference between, say, A and A, and the difference between (CH) and merely CH.

As before, thanks in advance for any information about using the TC-3.

Bama used to have all the Heathkit manuals, but had to remove them when Heathkit sold the rights to someone else. I see online prices between $8-$22.

This fellow has a TC-3 and can probably explain how to read the chart.
[email protected]

John

Here's a link to the assembly manual. Sorry, I don't have the operators manual. http://www.bobandersen.com/manuals/Heathkit%20TC-3%20Tube%20Checker%20WW.djvu

Bama used to have all the Heathkit manuals, but had to remove them when Heathkit sold the rights to someone else.

The "shell" of Heath sold the remaining rights - but Heath actually gave away the rights freely in the 1990's. I had a Navy buddy (Gino - yep, he was Italian) that wanted to distribute photocopies of the Heathkit "Hero" robot manuals for a robotics club and was granted a full release from Heathkit to copy and distribute "any out of support" manual. He had a real tough time in getting the letter - Heath was for sale at the time and they wouldn't even respond to his requests. Some time later, after they were sold (for like the second time in three years), he finally obtained his letter, first by fax, and then a hardcopy. This was all pre-1996.

I imagine that whoever bought the rights got the shaft from the shell of Heath that didn't realize that rights had already been given away. Due diligence, perhaps not.

Cheers,