After two very busy weeks, finally, a chance to have a look at the 8569B analyzer (with the 8565A control). No display, no way to find out if at least the essential items are working – these include the input mixers, the YIG filter and oscillator, and other GHz frequency components.
First tests showed that the power supplys are all working and well adjusted; still no display.
Connected a scope to the rear panel output – sweep is working!
Some little repairs of the CRT section (nothing really interesting to write about) – look at this sight:
Really great, a bright CRT, and well-focused. And, it is actually showing a signal – basically, a working unit. At least, a start. Now we just have to see how to get the controls fixed.
Hi Simon,
as you are deep in the HP8569A i need an advice where to start to repair my HP8569B. It is working ok on all ranges but not on band 6 22Ghz. When I switch to band 6 i hear realy clicking, the frequency display gets dimmed, and the screen is blank or has a spot. Looks like a short anywhere,
Ralf
Hi Ralf, there are many possible spots, really hard to tell what it could be. I can help you with good schematics if you don’t already have those. Do you know which rail fails?
Simon