[Amps] Tuning

[Phil Clements]

Subject: Re: [Amps] Tuning


> "Why not do a bench test with a good dummy load and a wattmeter? 
> Make a
> chart, and tune up in your favorite hangout area...."

Because you need the antenna you want to use with the amp. the loading 
will change
as  you QSY doing the test, and the wattmeter may move for the wrong 
reasons. I don't own any
antennas that are 1:1 vswr all over the band...maybe you guys do????


> To ad to that, you could purchase an antenna analyzer, adjust your 
> antenna
> tuner/transmatch for freq. for 50Ω.

Ttransmatches are very over-rated by the manufacturers. I only use 
them for balanced lines.
There was an article a few years back in QST about the loss figures in 
the different brands
of commercial transmatches. Very enlightning, indeed. Back in the 
'50's, the Johnson Matchbox
was referred to as the "Johnson Loss Box." Several of the more recent 
tuners are worse than a
Johnson. In addition, most tuners, except when using a resonant 
antenna, have to be retouched
sooner than the amp when moving about. If I can get away without a 
tuner and get a fair match,
this makes things less lossier and usually a little more broad-banded.

Then all you would have to do is hook up
> your amp with minor adjustments and minimum QRM.

I hate QRM as bad as Hiram Percy Maxim did......do your testing at 
noon on 160 and 80 meters, and
after the other bands close for the night.

(((73)))
Phil, K5PC