Tubes Asylum

Posted by newslogger44@gmail.com (A) on December 20, 2024 at 10:46:22

The Jackson 648 tube tester came with booklets entitled "Special Tube Data" to augment and update the roll-chart for subsequent tubes releases.

Printed in the rear of one booklet is "Form SP648/6 - No. 32-33/8-59"
The second booklet I have indicates "Form SP648/12 - No. 32-22/3-65"

The first booklet was printed in 1959 and the second in 1965.

Using the identical format as with the Jackson's internal roll-chart, the test procedure for tube 45 are as follows: 2.5 - 12 - A34 - 30W

For tube 80 there are two tests:
5.0 - 12 - 3 - 18W
5.0 - 12 - 4 - 18W

I inherited my Jackson 648 from a technician who retired many years ago and have had no problems with it regarding accuracy.

As is now common with such vintage equipment and relevant documentation, it is entirely possible that these booklets and others have already been uploaded online and can be downloaded as pdf files.

Good luck.