----- Original Message -----
From: "jbattin" <jbattin@msn.com>
To: "Bill Tippett" <btippett@alum.mit.edu>
Sent: Monday, September 15, 2003 9:41 PM
Subject: Re: Topband: Beverage measurements
I think one of things a stagger does is to not only phase the beverages
but
phase the vertical feeds to also null their pick-up in a given direction. I
think JI phases some of his beverages to get rid of Florida QRN. My
comments
on S/N ratio speaks to omni directional noise. It doesn't really take a
computer to get a feel of what is going on. If the forward lobe is 36
degrees, a 10x (or 10db) front to side/rear ratio will yield about equal
noise from the front lobe and the rest of the directions. If you have 16 db
front to side/rear ... then the front lobe noise will dominate the other
noise by 6 db.
My 9 element array has 30 - 40 db rejection off the side and rear. There
are a few times ..... and few is the word... that it makes a practical
improvement on QRN ... it often makes an terribly unusable band just
unusable. In your case, where there is a consistent direction for the noise
and the noise is of such a level that a 20 db. improvement will make the
band functional, it sounds promising. These issues are not a matter of few
db. one way or the other. It takes tens of db's to get something you can
hear.
John
----- Original Message -----
> From: "Bill Tippett" <btippett@alum.mit.edu>
> To: <jbattin@email.msn.com>; <topband@contesting.com>
> Sent: Monday, September 15, 2003 8:48 PM
> Subject: Re: Topband: Beverage measurements
>
>
> > Hi John!
> >
> > K9DX wrote:
> > >7. If you want better signal to noise, reduce the beam-width. Going
from
> > 15 to 30db off the sides or back, won't do much.
> >
> > Do you feel this applies to staggered/phased Beverages
> > (i.e.echelon)? My greatest noise problem is often thunderstorms
> > from the South-Central US when trying to listen toward Europe.
> > I've been considering staggered/phased Beverages as a solution
> > and believe this should help greatly. Even if individual Beverage
> > F/R patterns are not great, the result of a phased/staggered pair
> > should work fairly well IMHO. Any thoughts on this?
> >
> > 73, Bill W4ZV
> >
> > _______________________________________________
> > Topband mailing list
> > Topband@contesting.com
> > http://lists.contesting.com/mailman/listinfo/topband
>
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