On Mon, 29 Mar 1999 02:20:58 +0100 Pete Smith <n4zr@contesting.com>
writes:
>
>For whatever it's worth, my SB-220 will match an indicated SWR of well
>over
>3:1 on 80 meters (running my 80-CW array on 75 phone) with normal
>grid
>current. In other words, as long as the plate loading is capable of
>achieving a match, loading heavily enough causes the grid current to
>drop
>down where it should, and adding a little more loading gives some
>safety
>margin. I can see where this would be important for tubes with
>fragile
>grids, but the message is that excessive grid current isn't the
>unavoidable
>accompaniment to high-SWR loads, if the Pi network can match them.
Agreed. I have modified the output loading values of just about every
commercial amp I have owned to do just that on 80-160 over the years.
Either by increasing or decreasing the amount of fixed C.
Yes, it will upset the delicate balance of the Pi-net for the purists but
it works and I've never lost a bandswitch loading into VSWR's of up to
about 4:1.
I do not own an antenna tuner and have no need for another device of
questionable efficiency.
73 Carl KM1H
.
>
>73, Pete Smith N4ZR
>n4zr@contesting.com
>
>Loud is.
>
>--
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>
>
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