[Boatanchors] P&H LA-400 linear

[Ian Wilson]

I have seen a number of 4-65A's that have become gassy. Possibly this was
one of
Eimac's earlier attempts at the type of pin/glass seal? Obviously this is a
small sample
but out of perhaps 20 4-65A's I have seen 4 or more that were gassy.

On the other hand, have never seen a problem with 4D32/4D22 - these have a
satisfying 'like a brick' feeling.

73, ian K3IMW

On Fri, Aug 16, 2019 at 4:21 AM Rob Atkinson <ranchorobbo at gmail.com> wrote:

> GG usually takes more drive power for a given output power.  The
> schematic someone posted was 807s grid driven.  It was a complicated
> looking design compared to a cathode driven g.g. triode, but I assumed
> the point to it was to have a high gain 100 w. amp that could be
> driven by a dinky QRP rig.  If I were doing this and wanted such an
> amp I'd go with a single 4-65A or 4D32 and forget about a lot of 807s.
> If I were looking at cathode driven I'd try a single 812 or maybe
> 572B.
>
> Rob
> K5UJ
>
> On Fri, Aug 16, 2019 at 2:35 AM <hwhall at compuserve.com> wrote:
> >
> > Advantages of grounded grid, if I recall correctly, included not needing
> neutralization, and driver power not needed for drive was passed thru to
> the output.  IIRC.
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