View Full Version : RCA WT-100a Tube tester


SwizzyMan
03-31-2016, 04:21 PM
Just acquired this awesome tester. Built in 1956 this tester is a laboratory grade tube tester and has test accuracies of within 1%! This tester was used for research and development of tubes and was used at the RCA plant in New Jersey. You have to actually set each pin up individually to the right position so you would need a datasheet for whichever tube you are testing. It also applies up to 300 volts on the plate and screen grid! Does anyone else here have one of these and know how to use it?

Tim
03-31-2016, 08:59 PM
I acquired one and went through it about a year ago. Unless it has been recently overhauled, you'll find that a lot of the 1% resistors are no longer 1% so it will need a complete going through and calibration. There were several different versions of this unit so make sure the manual and schematic matches your serial number.

It is set up by using data from a tube manual so no "setup charts" are needed but they did publish one with some common tubes in it. Having only one meter for all functions is a little strange but it does the job and is a great unit to really analyze tubes. Enjoy it.

SwizzyMan
03-31-2016, 10:09 PM
I acquired one and went through it about a year ago. Unless it has been recently overhauled, you'll find that a lot of the 1% resistors are no longer 1% so it will need a complete going through and calibration. There were several different versions of this unit so make sure the manual and schematic matches your serial number.

It is set up by using data from a tube manual so no "setup charts" are needed but they did publish one with some common tubes in it. Having only one meter for all functions is a little strange but it does the job and is a great unit to really analyze tubes. Enjoy it.

Thanks for the info Tim! But your information has revealed a possible problem. My tester is the first version, but I bought resistors using the parts list from the second version! Hopefully version 1 and 2 do not differ too much in part choices. Do you know if your tester was the first, second, or third version Tim?

Tim
03-31-2016, 11:23 PM
Mine is kind of 1.5. :) You should be mostly OK with the parts.

SwizzyMan
04-04-2016, 04:35 PM
Here is a photo of the front panel for anyone who may be interested.

SwizzyMan
12-09-2016, 03:58 PM
Still looking for the documentation for the FIRST version of this tester. Any help would be greatly appreciated!

Tim
12-09-2016, 10:06 PM
I have what I believe to be the first version schematic. Dated 11/55. Shows a 6CB5 instead of the later 6DQ5 used as a regulator. PM your e-mail address to me if this is what you are looking for and I'll send it to you. What is your serial number?