[Boatanchors] 35Z5 Tube

[Gerry Steffens]

Seems like I remember an old kink.  The pilot lamp is in parallel with a
portion of the filament in the 35Z5.  If said lamp is burned out, the
section paralleled is stressed and has a very short life.  In equipment
where there is no pilot lamp, a suitable resistor is used.  This resistor
tends to change value and force more current through the filament segment
with the same unsatisfactory results.

It is also critical to have the correct lamp (either 44 or 47, I don't
remember which - or their screw-base equivalents).

Moral to the story, keep that pilot lamp good.

Obviously, limiting the inrush surge also helps but isn't necessary.

I have restored several AA5s without limiting inrush and they have operated
for years without a problem.

Gerry