[Swan] Re: Low output on 10m

[Mark Shaum]

----- Original Message ----- > From: "k7mks" <k7mks@attbi.com>
> To: <swan@mailman.qth.net>
> Subject: [Swan] Re: 350B - Low 10m output
>
>     My 350B exhibits low 10m output.  6MJ6 final is slight ly weak but
=
> gives me 80+W output on all bands except 10m where it is 30-40.   =
> Changing to another 6MJ6 or 6LQ6 or changing 6GK6 Driver, w/ coil =
> alignment each time, has no effect.  Everything else looks fine =
> (considering slightly weak final) including 15m.  Helpful suggestions
=
> would be welcomed.  Thanks Joe k7mks
>

Joe, most of the sweep tube final rings exhibit lower efficiency on 10
meters.  Most all of my rigs that use finals other than the good old
6146 show maximum output on 10 that is significantly less than that
available on lower frequencies.  The sweep tubes just were not made for
higher frequency RF work.  Some are better than others though, my NCX-5
only drops off about 20 percent on ten.

If  the tube voltages are correct on the driver and final, and you seem
to have enough drive, 30-40 watts may be all the 6MJ6 will manage to
deliver on ten meters.

73! - Mark  K9TR