If the SWR is a big thing to him, have him just build a simple L network and be
done with it. Rip apart an old AM radio for the capacitor and wind a coil. Tune
and tap and bingo, 1:1.
I would just leave it at 3:1, it's only a receive antenna.
My .02 cents worth,
Dave W1CTN
>
> From: Joe - WDØM <WD0M@centurytel.net>
> Date: 2004/11/18 Thu PM 03:35:33 EST
> To: Pete Smith <n4zr@contesting.com>, <TowerTalk@contesting.com>
> Subject: Re: [TowerTalk] K6STI Receiving loop question
>
> Still not a problem Pete - but if he was asking how to reduce the SWR -
> receive or not - that still didn't answer his question....just told him to
> ignore it.
>
> 73,
> Joe
> WDØM
>
> At 01:32 PM 11/18/2004, Pete Smith wrote:
> >Well, as a 'frinstance, if he's using RG-6 75-ohm cable, say 100 feet
> >long, and the antenna is presenting 240 ohms to the cable, on 1.8 MHz the
> >additional loss in the cable due to the mismatch is about .4 dB out of a
> >total of .8db, according to TLW.
> >
> >73, Pete N4ZR
> >
> > At 03:16 PM 11/18/2004, Joe - WDØM wrote:
> >
> >>Good point - how close is "close enough" - but if you're doing it the
> >>first time, why not 'do it right" instead of having to do it over? :-)
> >>73,
> >>Joe
> >>WDØM
> >>
> >>At 01:11 PM 11/18/2004, Pete Smith wrote:
> >>>On the other hand, if it is a receiving antenna, do you care? The
> >>>additional loss in the feedline due to SWR *may* be trivial in this
> >>>application.
> >>>
> >>>73, Pete N4ZR
> >>>
> >>>At 02:51 PM 11/18/2004, Joe - WDØM wrote:
> >>>
> >>>>Hi Dave,
> >>>>
> >>>>Perhaps the easiest way (if you have an antenna analyzer or access to
> >>>>one) is to check the impedance at the antenna using an antenna
> >>>>analyzer. That will tell you which way to go in modifying the turns
> >>>>ratio. I just put a beverage antenna together, and the analyzer was
> >>>>very helpful in assembling the transformer. I used my Autek analyzer -
> >>>>and it's probably the best investment I've made to be sure every watt I
> >>>>own gets to the antenna and then on to the other guy's radio. ;-)
> >>>>
> >>>>73,
> >>>>Joe
> >>>>WDØM
> >>>>
> >>>>
> >>>>At 11:47 AM 11/18/2004, Dave Quick wrote:
> >>>>>I recently put up a K6STI loop for 80m. It's about 8 feet off the ground
> >>>>>and built according to the plans in the Sep. 95 issue of QST. It's 21
> >>>>>feet on each side and I used 450 ladder (window) line and a 77 mix
> >>>>>ferrite bead for the transformer.
> >>>>>
> >>>>>My problem is that I can't get the SWR below about 3:1 or so. I do get a
> >>>>>dip as I adjust the cap, but never below 3:1. I'm guessing that I need
> >>>>>to adjust the turns ratio of the transformer, which is 4 turns to 10
> >>>>>turns as the QST article specifies, but I'm not sure which way to go
> >>>>>with the turns ratio.
> >>>>>
> >>>>>Does anyone have an advise for me?
> >>>>>
> >>>>>Thanks.
> >>>>>
> >>>>>Dave Quick K0EKL
> >>>>
> >>>>
> >>>>_______________________________________________
> >>>>
> >>>>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> >>>>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> >>>>any questions and ask for Sherman, W2FLA.
> >>>>
> >>>>_______________________________________________
> >>>>TowerTalk mailing list
> >>>>TowerTalk@contesting.com
> >>>>http://lists.contesting.com/mailman/listinfo/towertalk
> >>
> >
> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
> questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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