[Antennas] no radial vertical antennas

Tue, 16 Apr 2002 18:56:27 -0400

Despite all the technically correct and technically accurate reading we all
do, I think we are sometimes subliminal victims of the manufacturer's ads
and claims.  There is a tendency to believe that the manufacturers, having
lots of rf/antenna engineers on staff (most of whom are licensed operators
and/or licensed amateurs) do not bulls___ us.

Then I think about my own dilbert-esque organization and remember that even
we have marketing folks who sometimes 'outvote' the engineers.  The
advertised specs are ALWAYS correct. It's the rest of the ad that is
sometimes 'slanted'.  I would expect a manufacturer to stress their
strengths and omit their deficiencies.

One of the best technical review/policy mechanisms I've seen is ARRL's.
They won't accept an ad until they check the device in their own labs.  If
the specs are way off, they won't accept the ad.  The ARRL tests always
compare the maker's claimed specs against their own controlled environment
lab test results and then post the difference(s) in the review.

73
Frank

<<---  END OF MESSAGE --->>
----- Original Message -----
From: "Fernando Quinones" <[email protected]>
To: <[email protected]>
Sent: Tuesday, April 16, 2002 12:41 PM
Subject: RE: [Antennas] no radial vertical antennas

> Hello to All.
> I beleive this url was posted before, nice
> write up about radials.
>
> <http://www.bencher.com/pdf_download.html#tech_notes>
>
> enjoy
> --- Ron W7MRR <[email protected]> wrote:
> >  Hi Reggie:
> >
> >    You have hit on a topic that causes a great deal
> > of consternation among readers in this usergroup.
> > In any case, it is a valid question that you should
> > have the answer to before spending alot of money on
> > an antenna that fails to meet your expectations.
> >
> >    The antennas hailed as "radialess" verticals are
> > not really verticals at all but are end fed windoms
> > utilizing loading coils and, in some cases, capacity
> > hats to deliver an acceptable SWR over a number of
> > bands.  They go by the name of Cushcraft R-7,
> > R-7000, R-8000, the MFJ 1796 and others.  As a
> > group, they do not perform as well as full size
> > arrangements, but they do deliver a system that will
> > get you on multiple bands, albeit with a less than
> > commanding signal. This is a relative comparison,
> > but one that is supported by the many users
> > reporting to www.eham.com [reviews].
> >
> >    My experience with an R-7 that is roof mounted
> > [35 feet off the ground] when compared to an
> > inverted vee at the same height was that the
> > inverted vee was 1.5 to 2.0 "S" units better on both
> > receiving and transmitting on all bands [using a
> > tuner on the inverted vee].
> >
> >    So to answer your specific question, no I don't
> > believe 1/2 of the RF is going into the ground with
> > these antennas.  It is more likely being turned into
> > heat.  Again, however, if you only have 3 square
> > feet of horizonal space and 12-20 feet of vertical
> > space available for an antenna and want to operate
> > many bands, it may be the antenna of your dreams.
> > It's just alot of money to pay for an antenna that
> > could be out performed by $10 worth of wire and your
> > built-in transceiver antenna tuner.
> >
> >    If this discussion invokes the wrath of Kahn as
> > it has in the past, please read the responses
> > closely.  If they speak in terms of working
> > countries, DX, etc., understand that they are not
> > answering your question.  They are defending a less
> > than optimal investment.
> >
> >    Lastly, if you really want a vertical antenna,
> > you will need to consider the need for a good radial
> > system.  By the time you string and bury the 100+
> > radials needed for an efficient ground system, you
> > will have spent many times more than what a simple
> > wire antenna would cost and this is even before
> > raise the vertical radiator is raised!
> >
> >    Good luck and have fun.
> >
> > Ron W7MRR
> >
> >
> > --- On Sun 04/14, Reginald Mackey  wrote:
> > > I would like to install a vertical antenna and I
> > am confused as how some
> > > of
> > > them are advertised to work without radials? Even
> > the 80" radials
> > > seem to
> > > short according to typical vertical theory of
> > operation. What is the
> > > efficiency of these antennas? Can someone shed
> > some light on these
> > > antennas
> > > for me? For 3 to 400 dollars I would not want to
> > put 1/2 of my power into
> > > the ground.
> > > Thanks in Advance,
> > >
> > >             Reggie
> > > amateur radio station k6xr
> > > in southwest Bakersfield
> > >
> > > - - -
> > >
> > > Your moderator for this list is:
> > > Larry Wilson KE1HZ [email protected]
> > > _______________________________________________
> > > Antennas mailing list
> > > [email protected]
> > > http://mailman.qth.net/mailman/listinfo/antennas
> > >
> >
> > ------------------------------------------------
> >
> >
> >
> > --- StripMime Report -- processed MIME parts ---
> > multipart/alternative
> >   text/plain (text body -- kept)
> >   text/html
> > ---
> > - - -
> >
> > Your moderator for this list is:
> > Larry Wilson KE1HZ [email protected]
> > _______________________________________________
> > Antennas mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/antennas
>
>
> =====
> 73's Fernando NF6Q/NNN0JYM
> San Jose,CA.
> CCA #01187 FISTS #8649 K2 #2330 (in it's infancy)
> <http://www.geocities.com/nf6q>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Tax Center - online filing with TurboTax
> http://taxes.yahoo.com/
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
> _______________________________________________
> Antennas mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/antennas
>