[Boatanchors] Was 813 grid to filament... - now antenna tuners

[Rob Atkinson]

I prefer the term "matching network" because "tuner" is too vague.
That could be a component in a stereo audio system.
However the broadcast industry refers to the matching networks at the
bases of AM towers as "ATUs" or Antenna Tuning Units.

to save time I'll give my 0 cents on tube mounting.  We all have
opinions and I admit to being cautious and unnecessarily so sometimes.
As most know, small tubes can be mounted any old way, then there are
the ones like 572Bs that have to be mounted sideways only if pins X
and Y are in the vertical plane, and finally there are the ones that
have to be vertical or upside down (which I have never seen done).   I
never mount anything horizontal, if I have any control over it, even
the small octals and miniatures simply because I think heat is
dissipated better when they are vertical and the envelope is
uniformally heated all the way around.  But I have a driver stage in
my 3-400 rig with all its tubes horizontal (5U4, 6AG7, 6V6, 6146B) and
it works fine.  I would not have done it that way but it works okay.
Gear with bigger tubes that can only be horizontal if the filament
pins are in the vertical plane I always run vertically and anything
commercially made that has them horizontal, like the Kompact Kilowatt,
I simply do not purchase for that reason if nothing else.

Eico made an audio amp, the HF-12 that had the 6BQ5 output tubes at a
45 degree angle with the chassis top.  They cut 3 sides in the chassis
around each socket and bent the socket tab down so the tubes would
stick up but not straight up.  This was so it would fit in a lower
height cabinet, purely an aesthetic move and I always thought it was
dumb even if the amp still worked okay.  But those tubes get real hot.
  If I ever owned one, the first thing I'd do is bend the sockets back
up to the rest of the chassis and run the thing with the tubes
vertical and not bother with the cabinet.

73

Rob
K5UJ