Update,

My Dentron MLA-2500 has taken a back seat to my sons HS graduation, and
the 20th anniversary to my XYL. That said, I did sneak in a little time for
a few things:


1.) On 160 meters the 1000pf fixed loading capacitor is placed in parallel
with the 80 meter 1000 pf fixed loading capacitor. These are then in
parallel with the variable 500 pf (max) load control. Not much tuning range
here. The Dentron schematics are clearly wrong by not showing this. Sure
could use a bigger loading variable, and less fixed C for more tuning range.

2.) When replacing the RF PA plate load impedance with a carbon comp
resistor between 1500-2500 ohms and hooking my RF impedance bridge (Autek)
to the linear's 50 ohm output, I get a SWR null on all bands 160-10 meters
by tuning the pi-net for each band. This makes me want to reverse engineer
that pi net to figure out whatever the loaded Q may be, and to start
optimizing for my use with a 8877. I still agree with Tony that those
ceramic loading capacitors may be the crux of the problem because they are
not made of the right stuff for carrying hi RF currents; instead these are
made for bypass applications.

3.) The Alpha folks are trying to build a chimney for me with their Silastic
RTV material. I think they are either going to charge me an arm and a leg,
or kick the order back. This will be a custom design, and not an off the
shelf part. I may go back to the solid Teflon block idea, and try to find a
place that will machine it.


With SSB, or AM, doesn't a wattmeter show the average (over several
sylables) reading of the RMS power? :-)

Jim
WD5JKO