Re: "Sampler??"

On a sunny day (Sat, 3 Aug 2024 11:27:15 -0000 (UTC)) it happened Cursitor
Doom <cd999666@notformail.com> wrote in <v8l46j$3e34d$1@dont-email.me>:

There are several IFs, none of which none are 21.4Mhz according to the
notes in the text. They state the IF changes according to band, so it's
3621.4Mhz for band 0, -321.4Mhz for band 1 and +321.4Mhz for bands 2, 3
and 4.

 
Page 10 of the manual, quote:
rear panel IF outputs
 21.4 MHz IF Output

>
Wow! What a lot of IFs!

In
 HP_8566B_troubleshooting_and_repair_1.pdf
On page 55 see the 24.1 MHz originating from block A4A8A1
 then pasing through a gain control block A4A5,

On page 57 you see it being processed
 selectable bandwidth control A4A4
 log amplifer with filters A4A3
 log detector A2A2
and then to the recorder outputs (top left page 55)

The control part 'A4A9 IF control'
selects what you want to see.

So it seems to me the 24.1 MHz is the final filter?

It _is_ possible the graticule display is wrong not the display it self...
wild guess though, would need to measure some stuff.
Or maybe one of the PLL loops is locked at the wrong frequency.