See, "Ham Radio Techniques - 160-Meter Antenna Problems and Solutions," Ham
Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to
increase the radiation resistance by 9x. In the single and multi-wire folded
versions the ground loss resistance remained constant. Note that Bill was
obtaining his results from the K6STI antenna modeling software he was using. I
am not familiar with that program's capabilities or accuracy and it is clear
from the article he believed the results he obtained from it. It was the early
days of NEC programs for PCs and many of us were just learning how to use and
apply the antenna simulation programs.
It is impossible to know the basis for his errors in this case. But Bill's
contributions to amateur radio were vast and valuable and greatly overshadow
this one slip-up.
'73, Thomas - ac7a (Tucson)
---- "Wes Attaway (N5WA)" <wesattaway@bellsouth.net> wrote:
> Yes, he did. I remember the article from a long time ago. The theme of the
> article was how you could improve efficiency by folding the element. It
> raised the feed impedance and therefore reduced losses. I do not have the
> article at hand but I do remember it. If it was a QST article then it will
> be in their online archives.
>
>
> ----------------- Wes Attaway (N5WA) -------------------
> 1138 Waters Edge Circle, Shreveport, LA 71106
> 318-797-4972 (Office) - 318-393-3289 (Cell)
> Computer Consulting and Forensics
> -------------- EnCase Certified Examiner ---------------
>
>
> -----Original Message-----
> From: topband-bounces@contesting.com [mailto:topband-bounces@contesting.com]
> On Behalf Of ZR
> Sent: Thursday, August 02, 2012 5:58 PM
> To: Tom W8JI; topband@contesting.com
> Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
>
>
> ----- Original Message -----
> From: "Tom W8JI" <w8ji@w8ji.com>
> To: <topband@contesting.com>
> Sent: Thursday, August 02, 2012 6:21 PM
> Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
>
>
> >> (1) 130 feet of 300 ohms twin lead with the far one end shorted and
> >> pulled up over a coconut by a local climber $5 US max and connected to a
> >> small nylon line for adjustment in an inverted or sloping fashion back
> >> to my hotel room on the beach. (without the local climber bring along a
> >> slingshot fishing line launcher.) If the hotel wasn't right on the beach
> >> or had any 70 foot palms I just drove to another one that did. Masting
> >> anything up beyond 50 feet by yourself just forget it. Palm trees are
> >> great substitutes. I think this antenna was describe for 160 in Bill
> >> Orr's (W6SAI) firsts handbooks.
> >
> >
> > Just be aware Orr had a consistent mistake in his articles on folded
> > antennas. He claimed folding reduced ground losses by significant amounts.
> >
> > I'm not sure where that idea started, but using a folded element does not
> > change ground loss one bit.
> >
> > 73 Tom
>
>
> Did he actually claim that or that the effect of the ground loss was
> reduced? I dont have a reference handy.
>
> Carl
> KM1H
>
>
>
> _______________________________________________
> > UR RST IS ... ... ..9 QSB QSB - hw? BK
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
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> >
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|