"Mark Bielman via groups.io" <mbielman@...> writes:
That screenshot may have come from me. I don't have the CLIP handy
right now but it's the same one Shahriar used in his
videos. (PLL Unlock) I fixed 2 440x units that had the same fault as
in the videos from Shahriar. I verified the problem
by following his instructions. (you need a working SA to do this)
I'd have to check my CLIP to see if the is a U54 or not. I came across
another SA (4407) with this issue but it was a
newer board and did NOT have the div-by-4 counter. :-(
I didn't follow the thread closely so ignore me if I write something
that was said already. I have an E4407B which also had LO Unlock errors.
It had a newer RF board as you described. In my case it had a switchable
/4 /8 divider that is also used in the ESG generators. I used the
1GC1-4210 Replacement module, which works fine.
I learned that measuring whether output and input frequency are divided
by 8 or 4 doesn't help - in my unit it did scale down on most
frequencies, but failed at some. That of course confused the PLL while
sweeping.
