6DJ8 measurement error on Hickok 600A


My Hickok 600A measurement result is way off the spec of 6DJ8 tube. The tester is calibrated. I can get good consistent reading on 12ax7 tube. But i can only get ~7500 reading on 12000 tubes for 6DJ8. Anyone has the same problem on Hickok tester? Any idea how to solve it? Thank you in advance.
cygnus_859

Showing 6 responses by jea48

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600A manual

I have a Kickok 6000A. For a 6DJ8 the roll chart shows 7000 Mutual Conductance / MICROMHOS.

For a 12AX7 the roll chart shows 1250 MICROMHOS.
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Consolidated Test Data
For Hickok Model 533A-600A-605A
Tube Testers


Page 55
6DJ8
6.3 EV-7608-0 24 92 P4 9250 Triode #1.
..... EV-2103-0 24 92 P4 9250 Triode #2.
Mutual Conductance/ Micromhos, 9250

Where are you setting the English for the Mutual Conductance/ Micromhos test? The red dot near 92? Then use/read the 15000 scale?
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Thank your for your reply Jea48. I did set the tester as you mentioned. I still get about 7000 reading on new tubes (should be around 9250).
08-01-15: Cygnus_859

Cygnus_859,

Are the new tubes you are testing actually labeled 6DJ8 tubes or are they labeled 6922 tubes?

6922 ( Hickok 600A tube settings and Mutual Conductance readings.)
6.3 EV-7608-0 27 90 P4 6500 Triode #1. R
6.3 EV-2103-0 27 90 P4 6500 Triode #2.
Mutual Conductance/ Micromhos 6500.

What you are reading sounds more like a new 6922 tube.

7308 ( Hickok 600A tube settings and Mutual Conductance readings.)
6.3 EV-7608-0 27 90 P4 6500 Triode #1. R
6.3 EV-2103-0 27 90 P4 6500 Triode #2.
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Jim
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I found it is hard to get repeatable readings for 6dj8 tube. When I use 15000 scale, the reading is too sensitive to English position. Every step represent about 500 on the reading. I don't know if I have a bad English.
08-06-15: Cygnus_859
Each hash mark on the 15000 scale represents 250 Micromhos


I am still confusing about 6922 vs 6dj8. I can get over 10000 reading for some 6922 tube.
08-06-15: Cygnus_859
That sounds like you are not setting the ENGLISH knob at the correct RED dot on the ENGLISH dial. The RED dot you should be using is the one that has 15000 printed just below it.

6922 ( Hickok 600A tube settings and Mutual Conductance readings.)
6.3 EV-7608-0 27 90 P4 6500 Triode #1. R
6.3 EV-2103-0 27 90 P4 6500 Triode #2.
Mutual Conductance/ Micromhos 6500.

If you are setting all the knobs correctly and you are still reading 10000 Micromhos for a 6922 then there must be a problem with the supposedly calibrated tester.

How are the 9 pin tube socket connection tension of the tube socket? Fairly tight or loose fitting?

The ENGLISH Control ganged two pots may be dirty. You might try rotating the dial back and forth several times around the area of the 15000 scale RED dot.
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6922/E88CC

6922 ( Hickok 600A tube settings and Mutual Conductance readings.)
6.3 EV-7608-0 27 90 P4 6500 Triode #1. R
6.3 EV-2103-0 27 90 P4 6500 Triode #2.
Mutual Conductance/ Micromhos 6500.

>>>>>>>>

E88CC tube
6.3 EV-7608-0 27 90 P4 6500 Triode #1. F
6.3 EV-2103-0 27 90 P4 6500 Triode #2.
Mutual Conductance/ Micromhos 6500

Page 83
Consolidated Test Data
For Hickok Model 533A-600A-605A
Tube Testers


Did you figure out what the problem was with your readings?
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Jim