[Towertalk] Force 12 Sigma verticals

[Danny]

John , tnx for posting ur findings on the reflector.
They were vy useful.
Im abt to re-join the lowband crowd and currently testdriving
an inverted L ( with 2 elevated radials ) and a 1/4 sloper connected
some 30ft up the tower ( i know thats way to low but .... )
The Sigma 80 is another option , however something on the Sigma 80
page intrigued me.
It states : The only thing to enhance the Sigma 80 is to place it
adjacent to salt water.
Now , what happens if there is no salt water around ?
Ground is avg to good around here , but not salty :)
Is there a way to "imitate" this by using a ground screen ,
say by using sheets of chicken wire ?
Anyone an idea about this ?
tnx

73 Danny - ON7NQ -

ON7NQ@pandora.be

http://users.pandora.be/ON7NQ



----- Original Message -----
From: "John Petrich" <petrich@u.washington.edu>
To: "Finger, Bob" <Bob.Finger@DynCorp.com>; <towertalk@contesting.com>
Sent: Monday, March 18, 2002 8:42 PM
Subject: Re: [Towertalk] Force 12 Sigma verticals


> Bob,
>
>     I have not actually constructed my array just yet.  Have been using a
> single Sigma 80 on 80 CW for this past season and have compared it's
> performance to known antennas at this QTH.
>
>     1) The "standard" Sigma 80 is constructed for the SSB portion of the
> band.  Mine wouldn't resonate below about 3.650 MHz.  Had to order some 1"
> tubing extensions to get resonance to 3.510 MHz.  Not sure what
frequencies
> you are interested in, but bear this in mind if and when  you order.
>
>     2) The bottom line is that the Sigma 80 seems to perform equally to my
> full sized 1/4 wave GP, 20' elevated feed and 6 elevated radials.  The
band
> width is, of course, much narrower.  My 150' dipole is better for higher
> angle signals and less effective for LP than the vertical or the Sigma 80.
>
>     3) I rationalize the high cost of a Sigma 80 based on the vastly lower
> "hassle" factor compared to the alternatives (at this QTH) and the reduced
> "clap trap" factor in the garden.  I am putting mine up in September and
> taking it down in March.
>
>     4) My plans are to construct a fixed 2 element array for next year.
The
> design options are many.  I'm a firm believer in Roy's, W7EL, approach to
> driven arrays reflected in the ARRL Antenna Handbook.
>
>     Sorry that I cannot give you any first hand experience with the Sigma
80
> in an array.  Next year.  Maybe others are working on some and will
respond.
>
> Regards,
>
> John Petrich, W7FU
>
>
> ----- Original Message -----
> From: "Finger, Bob" <Bob.Finger@DynCorp.com>
> To: <towertalk@contesting.com>
> Sent: Monday, March 18, 2002 11:14 AM
> Subject: [Towertalk] Force 12 Sigma verticals
>
>
> > Has anyone built a triangle or 4square array using the Force 12 Sigma 80
> or
> > 40 verticals?  If so, what are your reactions both good and bad.  Seems
to
> > me like it might well be an effective solution (but expensive) to
limited
> > space where a full sized radial screen is not feasible.  Thanks for the
> > comments.  W9GE
> >
> >
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