The biggest challenge in even duplicating a tube checker will be in getting the setup information. For that, a person will need the tube information found in a tube manual. Those are becoming rather rare.
Is there any chance that we coujd see the circuit for the one the ts is considering?

 

The biggest challenge in even duplicating a tube checker will be in getting the setup information. For that, a person will need the tube information found in a tube manual. Those are becoming rather rare.
Is there any chance that we coujd see the circuit for the one the ts is considering?

Sure…. It’s old for sure and originally I looked around for the original parts. I have found all except the 25watt potentiometer. There are of course some modern parts that can replace old parts. Newer parts are cheaper too. It seems the older parts are held in very high reguard evidenced by the price wanted. Anyone selling should be thankful there is someone even looking at them. Circuit attached.

 

I have found all except the 25watt potentiometer.

I don't see a 25W pot in the circuit. I see a 25ohm on the 6.3v coil of the transformer. This would be about 2W pot, not 25w.

 

I don't see a 25W pot in the circuit. I see a 25ohm on the 6.3v coil of the transformer. This would be about 2W pot, not 25w.

R5. 5K 25watt. It’s listed in the second part of the parts list.

 

This is actually a quite good tube tester, although it is far more than you will need for servicing most radios. For those radios you will only need 7, 8, and 9 position tube sockets, and a grid-cap connector. Six and twelve volt s will be adequate for most tube types, except the 35 and 50 volt ones. For those heater voltages you can add a 24 volt transformer and put it in series with the 12 volt supply to get 36 volts, which should be OK for both.

R5, 5000 ohms is in series with a 5000 ohm fixed resistor across the high voltage supply. The wiper of R5 will carry the tube plate current, with radio tubes will be less than 50 milliamps, the rest of R5 will carry 250V/10,000 ohms current. So 2.5 watts will be adequate. I think that 25 watts is an error.

Note that this tester does not have the direct ability to check for inter-element short circuits.

The high voltage transformer can be any with those specifications for voltage, or similar voltages, and the various rectifiers can all be recent diode types like the 1N4006 or 1N4007, which cost just a few cents each and are easily available.

The "big deal" part of using this tester will be in having the tube manual that lists operating conditions, and the quite involved setup process. I suggest that you consider the setup process carefully before spending money on the parts.

 

Please help. Considering building a vacuum tube tester from an old magazine design. Parts seem to be an issue because of the 1950’s era age of the design.

I actually built a universal tube tester back in the `60's, one biggest challenge was rewinding a transformer to accommodate all the heater voltages out there.
I had/still have a copy of "Radio Valve Data" which claim characteristics, "over seven thousand Valves listed". (335,000 copies sold)
It may be possible to find an old copy out there, or a re-print?

 

I actually built a universal tube tester back in the `50's, one biggest challenge was rewinding a transformer to accommodate all the heater voltages out there.
I had/still have a copy of "Radio Valve Data" which claim characteristics, "over seven thousand Valves listed". (335,000 copies sold)
It may be possible to find an old copy out there, or a re-print?

You mean this one?

https://worldradiohistory.com/UK/Wireless-World/SPECIALS/WW-Radio-Valve-Data-1966-8.pdf

 

The RCA tube manuals are newer and probably a lot easier to find.

 

You mean this one?

That the boy !

 

This is actually a quite good tube tester, although it is far more than you will need for servicing most radios. For those radios you will only need 7, 8, and 9 position tube sockets, and a grid-cap connector. Six and twelve volt s will be adequate for most tube types, except the 35 and 50 volt ones. For those heater voltages you can add a 24 volt transformer and put it in series with the 12 volt supply to get 36 volts, which should be OK for both.

R5, 5000 ohms is in series with a 5000 ohm fixed resistor across the high voltage supply. The wiper of R5 will carry the tube plate current, with radio tubes will be less than 50 milliamps, the rest of R5 will carry 250V/10,000 ohms current. So 2.5 watts will be adequate. I think that 25 watts is an error.

Note that this tester does not have the direct ability to check for inter-element short circuits.

The high voltage transformer can be any with those specifications for voltage, or similar voltages, and the various rectifiers can all be recent diode types like the 1N4006 or 1N4007, which cost just a few cents each and are easily available.

The "big deal" part of using this tester will be in having the tube manual that lists operating conditions, and the quite involved setup process. I suggest that you consider the setup process carefully before spending money on the parts.

I have been, and all the input has been so helpful! The error seems reasonable when looking at the physical appearance of the potentiometer and it is not extraordinary large/robust in design.

 

They have a few "Valve" books still available.
radio valve data | Get Textbooks | New Textbooks | Used Textbooks | College Textbooks - GetTextbooks.com