instrument problem

Bill Stevens (wstevens@siu.edu)
Tue, 29 Oct 1996 09:15:05 +0000

Okay, folks, I've got one of those intermittent problems that may be
something one of you has experienced before. On my VXR-500, we have cooked
the TPL proton amp while supposedly doing normal proton pulsing. I managed
to "catch it in the act" once with my scope - instead of seeing the 100 us
pulses I was looking for, what I saw was dirty 445 MHz CW ! This coincided
with the TPL heating up.

Since then, we have fried the diodes in our high-band preamp four times. I
am trying to figure out whether the TPL is behind this or whether the
culprit is further back in the transmit train (which would have to be either
the xmit board or the driver amp).

Anybody experienced this?

Bill

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
William C. Stevens, Ph.D. Nuclear Magnetic Resonance Facility
Director Southern Illinois University
Carbondale, IL 62901-4405
wstevens@siu.edu
http://www.siu.edu/departments/shops/bill.html
wstevens@intrnet.net voice: 618-453-6498 fax: -6408
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