[Henry] Henry 2KD Classic help?

[David L. Thompson]

Sounds like one of the tubes has an intermittent short.  This has been a
problem with both the 3-400 and 3-500 tubes.  Usually this a grid to plate
short.  W6SAI told of shooting voltage to try and break the short.  I have
also had a problem where the filament lead comes unsoldered but in this case
one tube goes black.  I had a similar problem with an NCL-2000 that was
caused by a going bad BW Low pass filter.  The insulation inside was some
milar plastic that was very thin.  The arc burned a hole in the plastic.
One second it worked Ok the next it was as if there was no antenna. Hope
this gives you some ideas.
73 Dave K4JRB

> Hello List...
>
> I was working the ARRL Contest this morning and left the rig and amp on to
> do daily errands.  When I came back about 8 hours later I was very
> disillusioned when I keyed the radio and my amp began making a
> buzzing/arching noise.  The arc seems to vary with intensity from none at
> all to pretty loud.
>
> The amp is a 2KD Classic desktop.  Plate is running about 400ma and grid
is
> about 330ma.  Normally it runs ~600 plate and 225ish grid.
>
> Both tubes are lit normally and I don't see anything unusual when the amp
> is keyed.  It's difficult to tell where the arc is coming from.  And to
> make matters worse, it doesn't seem to arc every key.  The SWR is running
> about 1.5-6.1.  I *think* the SWR was lower than that originally.
>
> Is it possible one of the tubes may have gone bad?  They are Eimacs, but I
> don't recall if they are the originals.  I have owned the amp for about
> three years and have never had a lick of problem with it.  I can't recall
> if the guy I bought it from said they were originals or not.
>
> Can this amp be run with one tube at a time?  That might shed some light
if
> so.  When it rains it pours.  Two days ago my TS850 decided it wanted to
> whig out too.... shees, not much more here that can break!
>
> Thanks for any suggestions.
>
> Kelly - KE9KD
>
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