More Gonset Commander Questions Please?

DavidC eDoc at NETZERO.NET
Sat Jan 8 13:06:43 EST 2000

OK, the much hacked Gonset Commander HF transmitter a friend
is trying to repair for me apparently does not use the 7C5 specified
by the schematic.

Can folks familiar with this rig read JimC's description below
and speculate as to what may have been used, please?  Or
recommend what he should use now?  Would it be worth
redesigning to use the common 6L6 modulator pair?

BTW:  Is it possible that this is the Gonset Commander II?  Were
different modulator tubes used in the II?

- Thanks! & 73, DavidC  K1YP

   "Modulator tubes are NOT 7C5.  7xx tubes are 'loctal' types.
    Sockets on Gonset chassis are 7 pin miniature.  Guess you
    have a choice.  What do you want as modulator tubes - 6AQ5 -
    6BF5 - 6BM5 - 6DS5 - 12AQ5 (or several other possibilities)

    Suspect the 6AQ5 to be the best option.  Original tubes were
    not 7C5 either (sockets have not been changed).  Circuitry
    supplying the socket has been altered.  Since schematic shows
    7C5's in modulator application, and are not, how much more of
    the circuitry does not match the schematic?

    May be a real barrel of snakes.  No, wait just a moment.  6AQ5
    is a relatively tall bulb isn't it?  Chassis has 'hold down' clips for
    these two tubes and they may be for a shorter shucks!
    But then, we don't care so much about the locking clips provided the
    electronics are correct.  6AQ5 has an appreciably different Rp from the
    7C5.  But if the circuit was not designed around the 7C5 to begin may have to jack this one up and run another in under
    it.  And we wonder why our hair turns grey and falls out!"

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