One more comment...
On my 8170 amp I used a 20 Ohm, 25 Watt wirewound. When I first got my amp
working, I had made a mistake in the neturalizing circuit and the amp was not
fully neturalized and would bo BANG!!! during the tune up procedure. BANG!!!
as in 12 Ga. shotgun loud BANG!!!
I got the neturalization problem solved, but not before I went through 5 or 6
20 Ohm, 25 Watt wirewould resistors (in series with the B+).
Each time the loud noice shook my world, the resistor opened and removed the B+
from the tube. The only collateral damage was to the Screen Regulator crowbar
SCR. Never hurt a diode in the B+ supply or anything else.
If I had used a fuse in series with the resistor, I would have been replacing
fuses instead of the harder and more expensive wire wound resistors. Probably
would still killed the SCR though.
There, I said it. I am all done now...
-S
---- David Cutter <d.cutter@ntlworld.com> wrote:
> Glass tubes are not so easy to find: some plastics might do just as well
> filled with sand.
>
> David
> G3UNA
>
> ----- Original Message -----
> From: "Roger (K8RI)" <sub1@rogerhalstead.com>
> To: "Peter Voelpel" <df3kv@t-online.de>
> Cc: <amps@contesting.com>
> Sent: Tuesday, September 16, 2008 10:27 PM
> Subject: Re: [Amps] 3-500Z glitch resistor
>
>
> > Peter Voelpel wrote:
> >> Put the wire into a glass tube and fill that with sand
> >>
> >
> > Now that makes sense. Basically a HV fuse is just a tube with a wire
> > filled with sand.
> > If glass just make the diameter large enough to handle the pressure.
> >
> > 73
> >
> > Roger (K8RI)
> >> 73
> >> Peter
> >>
> >> -----Original Message-----
> >> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> >> Behalf Of Roger (K8RI)
> >> Sent: Dienstag, 16. September 2008 20:10
> >> To: Kevin LaHaie
> >> Cc: amps@contesting.com
> >> Subject: Re: [Amps] 3-500Z glitch resistor
> >>
> >> Kevin LaHaie wrote:
> >>
> >>> Harbach recommends a single strand of #32 or 36 wire create a fusible
> >>>
> >>>
> >>
> >> I really don't like the thought of a piece of wire in there long enough
> >> to extinguish the arc, or to coat things with vaporized copper. OTOH
> >> using regular fuses is inviting disaster. Most are rated no more than
> >> 250 v. HV fuses are difficult to find but about the only safe way to go.
> >>
> >> 73
> >>
> >> Roger (K8RI)
> >>
> >>> link, in series with the current limiting resistor. Makes sense -
> >>> inexpensive with big potential returns! A recommended source of this
> >>> wire being a single strand from a computer disk drive ribbon cable - we
> >>> all have those lying around!
> >>>
> >>> 73 Kevin K7ZS
> >>>
> >>> sccook1@cox.net wrote:
> >>>
> >>>
> >>>> Team,
> >>>>
> >>>> How about a resistor in series with fuse.
> >>>>
> >>>> -S
> >>>>
> >>>>
> >>>>
> >>>>
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>>
> >>>
> >>>
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >>
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|