preamp problems with the AMX

Peter Stilbs (sysstilbs@physchem.kth.se)
Wed, 29 Mar 1995 21:55:25 EST

During the last 1.5 years our proton preamp on the AMX-300 has broken
down at least 10 times, as we remember. This seems to happen between
experiments, and not during them. In 10-15 % of the cases the signal
level is down by a factor of 256/16 or so, and in the rest of the cases
it is completely dead, and one cannot even wobble - RG increments
up to 4096.

A repaired preamp and a modified transmitter (that would not 'ring')
were installed this afternoon - worked fine for a few hours, and
then the same story again ...

The thing is getting annoying, although the instrument is still
under warranty, and we get a new preamp in a few days ....

Has anyone of the BUM subscribers had any similar experience, or
knows a possible cure for this problem ??

Peter Stilbs

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Peter Stilbs, Prof. tel: +46 8 7908201
Physical Chemistry fax: +46 8 7908207
Royal Institute of Technology (KTH) E-mail: peter@physchem.kth.se
S-100 44 Stockholm, Sweden
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