09-17-2013, 04:00 PM
I can't tell from the picture but agree with Marty. If that intermediate socket has little tabs that come out from it where you can take measurements that is what it is. Very handy to have. I have a couple for different based tubes and it beats the heck out of measuring voltages from underneath the chassis.
Jerry
Jerry
A friend in need is a pest! Bill Slee ca 1970.