Hi,
I have repaired a few 3325a synthesizers. I have found that the Sample /Hold switches U20 and U24 have been broken.
These are quad devices, only three channels are used in each application. Sometimes swapping them will fix the problem.
If you have a manual check service group I
The part is an LF13331D. The part is obsolete.
A similar, inter-changeable part is used in the 3336 synthesizer/level generators.
Good luck !!
John Barnes
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---------- Original Message ----------------------------------
From: John Day <johnday@...>
Reply-To: hp_agilent_equipment@...
Date: Tue, 20 Nov 2007 09:15:50 -0500
At 09:02 AM 11/20/2007, you wrote:
Hello All,
I am having trouble tracking down a MC1495 or SG1495 or 1826-0437.
Its a 'wideband linear 4-quadrant multiplier' used in the AM and
Amplitude levelling in a 3325A.
Does anyone sell this chip anymore?
It has been obsolete for some time.
Although I have never tried this trick in a 3325A, I have used the
Analog Devices AD633 (readily available from DigiKey and others) in
other applications where I originally used the MC1495. It might be
worth some investigation.
I don't think I have the schematics of the 3325A, but if you can post
or email me the appropriate section I can try to sketch something out for you.
John Day
Toronto
Is there a functional / electrical equivalent?
Best regards,
Mark.
PS I have 3x A3 boards, all with the same problem!
Symptom is A-Cal fail, All 3 self test fail.
The voltages around this IC are all wrong.
mcs
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