[Test-Equipment] HP 8553B repair query

[Alan Melia]

Hi all, I wonder if I can tap into the vast pool of experience here in the
Group
I have an 8553 unit which is about 35 to 40 dB down on gain. I have removed
the A9 unit the 1st mixer and 200MHz amplifier module and want to disconnect
the 1st mixer to test the amplifier. The rudimentary test in the manual
suggests that the mixer diodes are OK.

I can release the  IF output SMB connector from the mixer to the amp, but I
cannot release the two connectors J2 and J3 which are the RF input and the
LO to the 1st mixer.  It appears as though the threaded sleeve on the
connector attached to the mixer module is used to lock the right-angle
adapter into to top die-cast cover. I can only rotate the "sleeve" about
1/8th of a turn withough it binding. I am cautious of applying too much
force, this style of connectors usually undo quite easily. I did wonder at
first whether the right-angle adapter was an SMB to SMC , but there does not
seem to be room for that, and the mixer will certainly not "pull" off
easily.

Can anyone, who has achieved this kind of repair, supply some ideas /
encouragement that I am proceeding in the right direction with the
mechanical disassembly. Am I just being too much of a wimp? does it require
more force?

Thanks for your interest.
Regards
Alan G3NYK
alan.melia at btinternet.com