Re: "Sampler??"

On Fri, 02 Aug 2024 12:02:43 GMT, Jan Panteltje wrote:

On a sunny day (Fri, 2 Aug 2024 10:09:24 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8ib8k$2p2d8$1@dont-email.me>:
 

On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
>

On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
 

...
I moved overseas and couldn't hold on to everything, sadly. Didn't
have time to find a museum either.

 
 
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.

>
Yes, first thing I did. And replaced any suspect caps.
>

Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)

>
No, the input stage is fine. I can see all the local FM stations at
their expected strength levels - but they appear to be about 20Mhz lower
than they are!

 
The 'about' 20 MHz is susicous, as the IF is 21.4 MHz.

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.

Looks almost like a problem with the calibration On page 12 of the
manual I see an internal reference output,
is that 10 MHz correct?

Yes.

What happens when yu feed in 10 MHz from an other source?

What's your thinking in that suggestion? What difference could it make?

 quote from that page:
  To lock the spectrum analyzer to an external frequency reference, set
  the FREQ REFERENCE Analyzer performance will be degraded unless
  frequency reference phase noise and spurious sign dBc single sideband
  (1 Hz) referred to 10 MHz at a 100 Hz to 10 kHz offset. To lock
  another spect the spectrum analyzer internal frequency reference, set
  the FREQ REFERENCE switch to INT

Well, I've just wasted several more futile hours trying to make sense of
the figures given in the manuals. This thing is a *bitch* it is *so*
complicated. I've never had to deal with something of this nature before
in all my decades in the hobby. Much of the problem is having to rely on
PDF manuals and HP having spread the relevant information over several
different manuals covering thousands of pages. Nice work, HP!