In a message dated 11/1/00 5:52:38 PM Eastern Standard Time, sjhel@aol.com writes:
I checked out the SND tube sales site the other day & discovered that Tektronix used to make a valve curve tracer (the 570). I do quite a lot of work on old valve equipment, (usually fixing guitar amps for friends) & it would be great to test the valves I have to see how well they match. Many amps that come in have an assortment of valves where one has been replaced when it has finally expired instead of a new matched set being fitted.
The 570 is a very rare item even here in the US. A friend of mine had one and sold it to a collector for a quite high price. You can see that very unit on the cover of Alan Douglas's "Tube Testers and Classic Electronic Test Gear". According to the book, only about 1000 were made over a period of ten years, starting in 1956.
