Home  Resources  References  Tubes  Forums  Links  Support 
Jackson 648A Tube Tester
6/7/2000 10:55:55 PMRobert
I recently received a small lot of 6C4 tubes that I
have been attempting to test with the subject tester
which has always been quite reliable. All of these
tubes check out at about 20% micromhos even though
they seem to work fine in their circuit. I'm wondering
if I have a misprint on my roll chart. The chart
settings given are Fil-6.3, D-234, E-A56, Plate-15, and
Test-W. Can anyone advise. Any help will be
appreciated. Thanks
6/7/2000 11:39:36 PMNorm Leal
Robert

You should be able set up the tester for a 6C4 then set adjustment pots for the 6C5 tube. Although different size the two tubes are very similar in spec.

Norm


: I recently received a small lot of 6C4 tubes that I
: have been attempting to test with the subject tester
: which has always been quite reliable. All of these
: tubes check out at about 20% micromhos even though
: they seem to work fine in their circuit. I'm wondering
: if I have a misprint on my roll chart. The chart
: settings given are Fil-6.3, D-234, E-A56, Plate-15, and
: Test-W. Can anyone advise. Any help will be
: appreciated. Thanks

6/8/2000 9:44:13 PMEd Kraushar
Hi Robert,

I checked the chart on my 648R. All of the settings are the same that you listed except that the test is WY indicating that those 2 buttons should be pressed together.

Ed.

6/9/2000 12:05:20 PMRobert
: Hi Robert,

: I checked the chart on my 648R. All of the settings are the same that you listed except that the test is WY indicating that those 2 buttons should be pressed together.

: Ed.
Hi Norm & Ed,
Thanks for the help. Ed, you were right on. I
rechecked my roll chart and sure enough, there was a Y
hidden under the divider of the window. Problem solved.
Us old guys need a lot of help. Thanks again.

6/9/2000 11:57:39 AMRobert
: I recently received a small lot of 6C4 tubes that I

: have been attempting to test with the subject tester

: which has always been quite reliable. All of these

: tubes check out at about 20% micromhos even though

: they seem to work fine in their circuit. I'm wondering

: if I have a misprint on my roll chart. The chart

: settings given are Fil-6.3, D-234, E-A56, Plate-15, and

: Test-W. Can anyone advise. Any help will be

: appreciated. Thanks




© 1989-2025, Nostalgia Air