My employer wanted to throw away a HP 8341A signal generator. This is a 10 MHz to 20 GHz sweep generator! Of course I rescued that unit from trash….

… and now I also know why it was thrown away:

there is this nasty sticker on it reading ‘the generator has been used as parts donator; following units are damaged: YIG oscillator, A55 YTO Driver’. Oh dear! But I know that the generator worked fine before these two assemblies were exchanged. So there should be good chances that it is repairable! And it is worth it, because it is an extraordinarily nice instrument. The parts removed from it were used to repair a HP 8340A, which is basically the same, but up to 26.5 GHz. So, apparently, the 8341 and the 8340 use the same YTO, which is good news because spare parts for either instrument would be ok.

This is how my unit looks:

This is how it looks inside. From top:

And from the bottom:

Typical HP stuff! And here is the bad YTO:

This is the A55 YO Driver board:

That looks like it should be possible to repair, however, I found a replacement on eBay for 30$, so I will try to repair this board but I have a spare 🙂

Now I am searching for a proper YTO….