Larry,
Looking at the (sparse) information available on the SGC web site.
it looks like the SGC-103 and SCG-104 are classic "wideband folded
dipoles." The length is given as 90 feet (27 meters) and frequency
coverage is given at 2-28 MHz. Both of those match the classic
WBFD numbers and the drawings appear to be much like the others.
I need to play with EZNEC a while ... given the complexity of the
WBFD (18:1 transformer and high power loading resistor), I wonder
if it would not be possible to construct a G5RV like antenna with
parallel wires (spaced 2 feet) that would have low SWR on all the
amateur bands between 3.5 and 30 MHz. It would not fill the need
of commercial/military for an ALE ready antenna but it would be a
"cheap and dirty" antenna for amateur use that would not incur
the 3 to 6 dB penalty from the WBFD "terminating resistor."
73,
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Larry Phipps
> Sent: Thursday, August 24, 2006 8:14 AM
> To: Joe Subich, W4TV
> Cc: 'TOWERTALK REFLECTOR'; 'James P. Cassidy'
> Subject: Re: [TowerTalk] B & W Antenna( was 2006 top ten)
>
>
>
> I recently read that, Joe. L.B. confirmed my assumptions, but
> it's nice to see a somewhat rigorous treatment. Do you know if
> the SGC broadband dipole is basically the same design?
>
> Larry N8LP
> www.telepostinc.com
> "Home of the groundbreaking LP-100 Digital Vector Wattmeter"
>
>
>
>
> Joe Subich, W4TV wrote:
> > W4RNL has done his usual excellent job modeling and studying the
> > "wideband folded dipole" (e.g., "the B&W Antenna"). See his
> > web page at: http://www.cebik.com/wire/wbfd.html. The quick
> > take away from his work is that a 90' WBFD is between 3 and 7
> > dB worse than a simple 90' doublet fed with open wire line and
> > a suitable tuner at frequencies above 6 MHz. Below 6 MHz the
> > losses in the WBFD increase significantly to the point that the
> > WBFD is down some 24 dB at 2 MHz.
> >
> > 73,
> >
> > ... Joe, W4TV
> >
> >
> >
> >
> >
> >
> >
> >> -----Original Message-----
> >> From: towertalk-bounces@contesting.com
> >> [mailto:towertalk-bounces@contesting.com] On Behalf Of James
> >> P. Cassidy
> >> Sent: Wednesday, August 23, 2006 11:16 PM
> >> To: TOWERTALK REFLECTOR
> >> Subject: [TowerTalk] B & W Antenna( was 2006 top ten)
> >>
> >>
> >> At the risk of being fatally flamed I want to add a couple
> >> cents worth to
> >> the B & W Antenna issue.
> >>
> >> I had read the same info for many years about the
> >> ineffectiveness of the B
> >> & W antenna. This past spring I operated at a station that
> >> uses one and
> >> was slightly amazed at the performance. No, its not a world
> >> beater contest
> >> antenna but did work well enough in the CQ WPX SSB contest to
> >> work quite a
> >> few stations on 160,80 and 40m. There was no other
> antennas for those
> >> bands to compare with but the main point is that it did
> >> radiate well enough
> >> for some QSOs. Of course in the contest situation there was
> >> no accurate
> >> signal reports and its very likely that the signal was
> below that of a
> >> conventional dipole.
> >>
> >> The bottom line was that the station was capable of making
> contacts.
> >>
> >> And before I catch too much flaming, the antenna is not at my
> >> station.
> >> Only at a friends with somewhat limited space for wire antennas.
> >>
> >> 73 Jim KI7Y
> >> _______________________________________________
> >>
> >>
> >>
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> >>
> >>
> >>
> >
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> >
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> >
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