I picked up a couple of 50s/60s tube testers. Both work, but they don't quite agree with each other on the strength of any given tube. For some tubes, the FC-2 nails the Vu meter past 100%.
I don't know anything about these things, but it looks like a very simple circuit.
1) Is one of these capacitors key to the reading on the tube?
2) On a "device" like this, can I get away with replacing that 0.5uf 200v capacitor with two 1uf100v in series? That's what I have on my bench, and I don't really feature ordering parts for a thing like this, if possible. I think I have the .01uf and .002uf.
Any experience on working on these things would be welcome.
schemo: TV-II
schemo: FC-2
First pic, TV-II
Pic 2&3 FC-2
I don't know anything about these things, but it looks like a very simple circuit.
1) Is one of these capacitors key to the reading on the tube?
2) On a "device" like this, can I get away with replacing that 0.5uf 200v capacitor with two 1uf100v in series? That's what I have on my bench, and I don't really feature ordering parts for a thing like this, if possible. I think I have the .01uf and .002uf.
Any experience on working on these things would be welcome.
schemo: TV-II
schemo: FC-2
First pic, TV-II
Pic 2&3 FC-2
I own both a Mercury 1000 and an I-177 (military) tube testers.
To calibrate them, I purchased several NOS recommended calibration tubes and measured their GM and Mu using the tube manufacturer operating parameters.
I then used the tubes to calibrate the test sets.
For the Mercury 1000 I use 6BA6/JAN5749W.
Tube Testers from different manufacturers will give different results. What is important is that the results agree with the manufacturer's stated results in their test table.
To calibrate them, I purchased several NOS recommended calibration tubes and measured their GM and Mu using the tube manufacturer operating parameters.
I then used the tubes to calibrate the test sets.
For the Mercury 1000 I use 6BA6/JAN5749W.
Tube Testers from different manufacturers will give different results. What is important is that the results agree with the manufacturer's stated results in their test table.
Yes to the cap or use a 470n.
RE calibration as Mr Gimp says one usually uses a calibration valve but for emission you could use a resistor between anode and cathode, a 33 1% at 200v say should give 6mA.
It might be an idea to protect the meters, once dead they are impossible to replace, use back to back diodes.
Andy.
RE calibration as Mr Gimp says one usually uses a calibration valve but for emission you could use a resistor between anode and cathode, a 33 1% at 200v say should give 6mA.
It might be an idea to protect the meters, once dead they are impossible to replace, use back to back diodes.
Andy.
There are a lot of similar testers that are just looking at cathode emissions, which is a useful guide to the amount of life left in a tube, but they miss other useful checks such as gas and shorts, or more quantitative testing such as creating curves and measuring gm.
I have an Italian version of the TV-11 and the goal is to try and shoehorn a uTracer into the box. The multitap transformer would avoid the pulsed heating of the uTracer, and the hard part with the case having all the sockets is solved. Has anyone done that, or enhanced the testing capabilities of one of these?
I have an Italian version of the TV-11 and the goal is to try and shoehorn a uTracer into the box. The multitap transformer would avoid the pulsed heating of the uTracer, and the hard part with the case having all the sockets is solved. Has anyone done that, or enhanced the testing capabilities of one of these?
Great, thanks, that's helpful. So you're saying that a 33k resistor between the anode and cathode on any given tube socket - let's say the one set to test a 12ax7 - should show 6ma on the meter? Would that read 100% on the unit's VU meter?
How and where would I put diodes to protect the meter?