In the L4-B power supply, Drake used an IRC type BWH/SPH "fail-safe"
resistor (0.82 ohms/2W) as a fuse to protect the diode strings in the event of
a short or closure of the RF deck cabinet interlock.
The resistor is still a current IRC product (as a type SPH device), but is not
a
high demand item, and is out of stock at every IRC distributor I have checked
(including Drake). So while it is "available" it is essentially Unobtainium.
Newark wants a minimum order of 250 each to even go ask IRC for a
production run. At $0.44 each, that makes a pretty expensive price for
ONE ;-)
So the question. Is there some generally accepted alternate method for
protecting HV diode strings? A wire fusible link, perhaps? Or is this even
considered necessary? Would just leaving the part out create an
unacceptable fire hazard? etc.
Grant
----------------------------
Grant Youngman -- NQ5T
nq5t@home.com
http://www.globeking.com
Double Oak, TX (near Dallas)
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