[Boatanchors] HV fusing in amplifiers

[Mike McCarthy, W1NR]

Bussman type HV fuses are made just for that purpose.  I have an old Henry
2K that uses an HVB-2 in the high voltage line.  When it blew, I soldered a
piece of #30 wire wrap wire across it.  I have not found any place to buy
just one, only by the box of 40.  HVB's are rated for 2500V.  I have a box
of HVJ-2's which are rated for 5000V at 2A but are much larger in diameter.
Bought them at a flea market.  See
http://www.bussmann.com/library/bifs/6003.PDF for specs.  Mounting is via
metal clips attached to ceramic standoff insulators.

For real cheap, a 3" piece of #30 suspended between ceramic standoffs would
work just fine.

Mike, W1NR

-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Rbethman
Sent: Wednesday, May 04, 2005 7:59 PM
To: Boatanchors at mailman.qth.net
Subject: [Boatanchors] HV fusing in amplifiers

Group,

Has anyone thought about high voltage fusing in an amplifier or "old" BA?

Usually there is a choke in the RF output leg to ground, in the event that
the plate blocking cap fails.

Yes, we usually have power supply fuses or circuit breakers.  BUT - what
will get fried?  How do you protect all that?

I've got ONE HV fuse by GE.  Its design voltage is 2400V.  It is rated at
7A, which is obviously a ridiculous value.  HOWEVER, even IF it was a
reasonable current rating, it is HUGE!  It is 11" long and 2" in dia.

Where in the world would you even mount it?
--
Bob - NØDGN
                       Bob Bethman - NØDGN
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