Hickok 600A

All I know is, that in spite of any negativity of the 600A,
I really like mine alot. much easier to lug around and works just as good as my 533.
Mine too was used but well cared for. the case did nit even have any tares or rip ups
and the front panel is very nice and clean and the scrool works.
I think U did good tube-a-lu

Thanks Ferninado, it seems like a great tester i just worry I can't be able to restore it all
because I don't have a scope for some of the tests.
 
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tubealou, Ill have to check my cal proc to see what the scope is needed for.
U may can get by without it.
will let U know.
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OK, I have 2 cals for the 600a. one by hickok and one by a 3rd party in the 21st cent/ 2007 or so.
Anyway the hickok proc does not call for a scope to cal.
The other proc does altho no adjustments are made. just observing
120hz peaks waveforms. 2 tests for some balance use a scope.
so U may get by with no scope.

let me know if U need one or both and I will try emailing to U.
 
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Started doing some test with the Hickok and and everything seemed okay till I
got to the plate voltage and it should be 150volts DC put it went up to 200volts.
I have the incoming voltage set at 117volts, looking at the calibration sheet I have
to check R24 and R25 to see if their okay, they might be out of spec.
 
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Do the voltage tests first. I wouldn't replace the 83 with a solid state unit unless your ready to have all the voltages off. Your 83 can still be good and voltages can be off for many other reasons. I think in the 600A the 5Y3 is for the screen voltage and if it goes bad the tube testing won't work at all or will show a very high reading. I'd have to check the schematic.
Set it up as shown to test the 6L6 tube. Ignore the line set for now and check the plate voltage. I believe it is pins 8 (negative) and 3 (positive) for the 6L6. If the plate voltage is 150VDC +/-5V, than the resistor in the circuit for the meter has changed value. Make sure you use a shunt resistor across the test points if you use a DVM or VTVM when checking the plate voltage or you will get a high reading of around 190-200 VDC as its pulsating DC and not pure. A 100K or close to that will work. I remember my resistor in the meter circuit had changed when I went through it for the first time and I had to change it to get the meters pointer to the right spot. It read low as well. I believe the resistor is located on the pushbutton assembly center/top. You may have to change that resistor, while keeping the plate voltage at 150VDC until the pointer hits the test spot. If you move the positive lead on your meter to pin 4 you should read the screen voltage of around 130VDC. The 5Y3 could correct a problem with this voltage. BTW you need to push the P4 button while taking any of the voltage tests.
Try this first and see what you find.

I found this about the high voltage that another Ak'er was having, maybe this is this is the problem.
 
Didn't have a 250K but I tried the above 100K and it worked voltage down to 153volts DC
that's a lot better, I wonder if I should use this and a smaller resistor for the other test as well.
 
Okay this isn't good, it was running smooth doing the test till I got to the
Grid Bias Voltage and Reduced screen voltage test's, so the Bias has to be
set at a -39 volts and the screen voltage to 56 volts. So I adjusted the
wirewound resister till it stopped giving me a signal because the little
wires broke. Now I need to get another one does anyone have any idea
where I could get one or does anyone have one to sell??
It's says 1AV 8500 on it.

Thanks
 
Okay I lucked out on ebay someone was selling parts from a 800A and it was the Rectifier
tube section sockets plus it had three resistors including a 8500 which I need.
 
Hi Guy's, well I installed the new 8500 Ohm resistor and set the Reduced screen voltage
test to 56.5 volts and Grid bias voltage you have to turn the bias control dial to 100 and
then make sure the max voltage to -39 plus and minus 1volt, I got it at -39.50, the
resistor is a bit hard to set but set it I did. So far all the reading are all good I haven't
tested any tubes yet but soon. The only other test I did not do yet is the English control
I'm going to have to pick up a 10k 10 watt resistor and and go thru test the range that it
doesn't vary by 0 to much but that will have to wait till I get the resistor.
 
Guy's decided to do my first test with a 12AX7 tube and it's off one minute I test it and it's at the
middle of the scale on good if I wait a few minutes it shoots up past good, yikes something is off
any ideas?? maybe I didn't let it heat up enough their is two tube inside I going to test the
5Y3 tonight to see if it's good and I have another #83 that I got tested god by the seller.
 
All this talk of mercury rectifiers had me pulling out a flea market find. It's a GL-872A and that has a small puddle of mercury in it. More than I have seen in any other tube.
I don't worry much about mercury in it's liquid form, now the heated gas I have a lot of respect for.

BillWojo
 
I hope this thread still has some life in it. You contributors have been a great help so far and I likely need to read this all again. I just bought a refurbished 600A and have tested some 80 rectifiers and 27&56 5 pin tubes and all seems to be working properly. I then moved to some 6sn7s and my confusion has grown. How does one tell which gm scale to read? Min good is 2,600. The 3 scales all start with 0 so they overlap. My sample reads either 2,500 or 5,000 on one section. Both seem feasible. Which is the actual reading?

Also, if anyone could confirm or deny that:
KT77 settings would be the same as EL34
Russian tubes would have same settings as US/EUR equivalents.

I understand that the selector dials would be the same as similar pinouts. Is there a way to set bias and english dials by referencing the tube data sheets? Same question for min gm?

Thanks you in advance!
 
Ok, so I figured out the first half of my question. I knew it was operator malfunction. I'm starting to get a little feel for this device, as well the comments in this thread about relative accuracy. I am still curious about tube settings for tubes similar but not listed on Steven Johnsons website?
 
I have reviewed the compiled lists. Though much more comprehensive and greatly appreciated I happen to desire some settings unlisted there. Surprising KT77 is not listed. Not surprising the USSR tubes are not. As I get to know this tester I'll bet I can get some refernces to work with. Of course any additional input or advise is welcome.

About my 600a. It came tested and refurbished. So far it seems to be working properly. I do need a reference tube and it seems like it would be helpful to have one for 0-3000, 0-6000 and 0-15000.
 
I do need a reference tube and it seems like it would be helpful to have one for 0-3000, 0-6000 and 0-15000.

Hickok used an metal-can RCA 6L6 as the calibration tube.

The catch is that one must verify that the calibration tube is itself within normal bounds so that requires a working tube tester. Some Catch, That Catch 22. You need a guaranteed NOS tube, not what some eBay seller alleges is NOS, but which actually has more mileage on it than the proverbial car driven only to church on Sundays.

This is why it is nice to have friends with calibrated tube testers. Because when one only has one tube tester one always know what values one has; when one has two tube testers one can never be certain.
 
There is one guy on the web who sells certified 6L6 calibration tubes. I have thought of buying one myself. Probably could rent it out to AKers to check and calibrate their own testers.
 
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