[1000mp] AMP Question

[Rod Elliott]

Dick...

I use a Mk5 Field to drive an AL-1200. No problems... works great.

In my experience the SWR presented to the Field by the amp's input is 
always well below 2:1, even if the output of the amp is not perfectly 
matched. The Field has no problem with that.

One precaution... do NOT use the Field's internal antenna tuner when 
driving the amp. (The amp's input impedance varies with drive 
level... you don't want the Field's tuner to strip its gears trying 
to follow your voice! )

73
Rod VE3UW


At 14:21 5/3/2007, you wrote:

>I have had a MARK-5 FIELD for a little over a year and have it filtered well
>with INRAD filters. I have never used my amp with this rig and am thinking
>about putting it in line. Last November there was a thread about amps and
>the Mark-5. I do not have an outboard tuner, only the Mark-5 internal tuner.
>I seem to remember some problems concerning the use of an amp with this rig.
>I would appreciate some advice. I am not able to purchase a new tuner at
>this time. I don't use an amp 95% of the time. But there are times it would
>be nice to have ( ie: BS7H).
>
>Here is what I have:
>   Ameritron AL-600 amp (it is 10 years old)
>   My Mosley 4 element YAGI does not require a tuner from the bottom of the
>band up to 300 on 20 meters.  The SWR is never
>    over 1.2:1 on this band.  15 meters is almost as good and 10 meters not
>quite as broad banded. Both 10 and 15 M have SWR not over 1.2:1 up to 100
>from bottom.
>
>Question- Can/should I run this amp without and external tuner, or am I
>risking damaging the Mark-5 ?  Advice and comments appreciated.
>
>73  Dick  KS0M
>
>Richard C. "Dick" White
>Fulton, MO. 65251  U.S.A.
>whiter26 at sbcglobal.net
>
>Live simply. Love generously. Care deeply.
>Speak kindly. Leave the rest to GOD.
>
>Amateur Radio Station - KS0M
>
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