[Heathkit] SB-301/310 Mods

[Chris Trask]

>
> >    I'm going to do a tuneup on my SB-310 (yes, that's SB-310, not
SB-301),
> > and was wondering if anyone knows of any tube replacement mods to these,
> > probably more in regard to the SB-301.  The 6BZ6 RF amplifier is okay,
but
> > I'm certain that there are better tubes than the 6AU6 for the mixers and
the
> > 6BA6 for the second IF amplifier.  An article from QST or CQ would be
nice.
>
>
> And because this list is set up to have replies go to the poster instead
of
> the group, please do summarize your responses to the group.  I have two
> SB-310s I have to get to one of these days when it gets too cold around
> here - i.e., below 80° - to sit on the beach drinking beer & watching
> suntans walk by.
>
> DanF
>

    The only reply I've had so far suggests replacing the 6AU6 mixers with
6HS6's.  I looked those up, and it has twice the transconductance of the
6AU6 and a litle more than half the ENR, so there is a definite gain and NF
advantage.  And the 6HS6 has a much better looking saturation region, which
gives it a bit of an edge on linearity.  Plate resistance is about the same,
so it's pretty much a drop-in replacement.

    Tried to find some online from the usual suspects, and the 6HS6 is not
easily found.  And the prices I saw were outrageous.

Chris

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