[1000mp] MPV Driving Amp

[Scott Manthe]

The tuner in the Mark V isn't passive. If you use the rig's tuner while 
you are tuning up the amp, you'll find that the tuner will "wander," 
causing the output of the rig to vary and making tune-up more difficult.

There are other reasons I'm sure the more technical types on the list 
will come up with, but for me, this is a very good reason not to use the 
rig's tuner. If the amp is already tuned, of course, this is not a problem.

73,
Scott, N9AA


Win wrote:
> I have heard, or read on this list, that you should not drive an amplifier with the tuner in line. I am sure that there is a good reason for this, but I can not, for the life of me, figure out what is is.  
>
> Yesterday, when a DX station I needed appeared on 15 meters, I switchewd the amp over and started tuning.  The SWR going into the amp was 2 to 1, limiting my drive.  This is probably because of some mods I made in the amp.  In any case I turned on the tuner and matched to the amp, and made the contact.  
>
> Correcting the problem with the amp is nothing more than adding a cap to the input circuit the nexty time I am into it..  I still ponder, however,  why I should not use the tuner into the amp.  I have done this before many times with other rigs using passive external tuners.
>
> Win
>