[Antennas] Re: Your Antenna "pre-selector" Desires....

2002年5月31日 12:29:11 -0500

I would be careful about just loading the antenna with an inductor or a
capacitor alone. That can result in the development of high voltages or
currents at the antenna connector of the radio and thereby could damage the
internal tuner. Depends upon a lot of variables that you probably neither
know or can control.
I agree with Karl - who doesn't? - that what you want to do is to employ an
impedance-tranforming circuit - a "tuner" - in the coax line to the end of
the antenna and set it for the lowest SWR you can get.
Then you can fairly safely let the internal tuner do the rest of the job.
I guess I am a sissy, but I really never use any of my internal tuners
unless I am absolutely sure that they are not going to see more than about
a 2:1 SWR from the antenna system, especially so when an external tuner is
in use.
Internal tuners are basically "tender" and just cannot stand voltage or
current extremes like a rugged external tuner can. And they are $$$ to
repair! <:}
73/72/oo, George W5YR - the Yellow Rose of Texas 
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe 
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
Icom IC-756PRO #02121 Kachina 505 DSP #91900556 Icom IC-765 #02437
Tim Billingsley wrote:
>> Well that was my line of thinking in general. If I was to build a selectable
> inductor and put it inline then I could try to use it to bring the SWR into
> a more reasonable range and then kick in the autotuner to take up the slack,
> therefore I am not stressing the TS-570 as bad.