[Boatanchors] Knight-Kit 600 series tube testers

[John Myers]

Hi,

I just recentky picked up a couple more tube testers, that I intend to
resell. In starting the repair process, a question came up.

The first one it a Knight-Kit 600 series tester. I only know that it's a 600
series, because it is almost identical to my regular tube tester. I can't
find a model number on either one, though.

Can anyone shed some light on why this is? I'm assuming that the model
number must've been on a removable tag, which has failed the test of time.

Anyway, this one has some of the worst soldering I've ever seen. I have my
work cut out for me, to get this one functional again.

Also, if anyone has pdf or jpeg of a schematic for this, I'd appreciate it.

Thanks,

John, KD8MQ