[80m] 4 square

Fri, 11 Jan 2002 15:30:20 -0500 (EST)

BTW Ken.  Although Paul is promoting elevated radials, if he had more like
60 burried radials on each vertical, the ground mounted system would work
better than the elevated system and the bandwidth would be more in line
with the elevated system.  A ground mounted system is also MUCH more
predictable.  By that I mean, the system will work as predicted where a
raised system is more likely to have less F/B than the model predicts.  
I've seen this with my systems all using the Comtek box.

If you can't put a lot of ground mounted radials in, then go the raised
route.  If you can get the ground radials in (at least 30 on each), then
go with the ground mounted system.  

Also... When I had a wire 4-square, I noted the same thing as Paul.  The
array worked on one mode or the other.  My current system is Rohn 25 tower
sections and it seems to work on both modes if tuned for 3650Khz, but I
don't operate SSB.  W8JI uses wire elements on his 4-square in a bow-tie
configuration.  Two elements that go up to a line seperated at the top by
some distance.  Each element looks like a V.  This provides addtional
bandwidth without the need for tower elements.

73

Bill, W4AN

On Tue, 8 Jan 2002, Paul Playford wrote:

> Yes.  But the limited SWR bandwidth is an indication that the system is
> working.  When I had my 40m 4sq installed with buried radials (8 for each
> element) the SWR was flat across the 80 and 75m bands but it's performance
> was not very good.  With the elevated radials (4 for each element) it
> narrowed the SWR bandwidth and now it works very well.  I didn't try the 80m
> with buried radials, just went direct to 4 elevated at each element and it
> works very well.  The array is tuned for 3540 KHz and does give good results
> on 3800 but I am sure if I redid it for 3800 it would work better.  I'm just
> not into DXing by committee, although when I get desperate enough for a new
> one I do go to 3800 <grin>.
> 
> I use a Comtek phasing box to feed the arrays.  I have done a lot of
> modeling (Eznec) with both the Comtek feed and a parasitic feed and
> according to Eznec I cannot build an 80m array that will work on both 80 and
> 75.  If it works on one band, the signals go straight up on the other band,
> hence my belief that 80 meters and 75 meters are two seperate bands.
> 
> Oh, you cannot measure SWR when using a Comtek box.  The resonant frequency
> is determined by how much power is going into the 5th port.  With the ground
> mounted radials I never observed any power going into the 5th port and with
> the elevated radials I get as much as 300 watts (wasted) when operating on
> 3800.
> 
> de Paul, W8AEF
> 
> ----- Original Message -----
> From: Ken "AB5A" Eckel <[email protected]>
> To: <[email protected]>
> Sent: Friday, January 11, 2002 6:42 PM
> Subject: RE: [80m] 4 square
> 
> 
> > Paul,
> >
> > When you use a tuned raised radial system, do you limit the bandwidth that
> > is usable?  It would seem to.  I have my 4 square up with 4inch pipe and
> 67'
> > elements.  I have not completed my ground screen yet.  But have watched
> > the raised radial issue.
> >
> > 73,
> > Ken AB5A
> >
> > -----Original Message-----
> > From: [email protected] [mailto:[email protected]]On
> > Behalf Of Paul Playford
> > Sent: Saturday, January 05, 2002 11:54 PM
> > To: [email protected]
> > Subject: Re: [80m] 4 square
> >
> >
> > I am using a 4 square with 4 elevated radials on each element and it works
> > great!  The feed point (and radials) are about 9 feet above the ground so
> it
> > is easy to walk under them.
> >
> > I use 3" irrigation pipe for the bottom 30 feet of each vertical element
> and
> > taper down from there up to 67 feet +/-.  Each element is guyed at 4
> levels
> > to keep our 80mph winds from destroying the array.
> >
> > I also have a 4 square on 40m and when I first installed it I ground
> mounted
> > it and buried the radials.  I never was happy with it and was just about
> > ready to discard it when I moved to a new location and tried the elevated
> > radials.  It is my opinion that elevated radials are the only way to go.
> >
> > I have convinced myself that the reason that am broadcasters use buried
> > radials is that they want their signal to stay in the ground for local
> > communications.  As DXers we want our signals in the air, but close to the
> > ground.  Hence, elevated radials.
> >
> > 80m propagation is a study in itself.  I often hear EU on 75m ssb but the
> > 80m band is still dead.  And I have concluded that they are two seperate
> > bands!  It does get rather discouraging to listen to the East coast USA
> > working EU using a dummy load and running QRP and I cannot work them with
> my
> > 4sq and 1500 watts (from Arizona), but then that makes me rare DX for EU.
> I
> > used to think that they just could not hear me but occassionally I see
> > myself spotted in EU so it (doesn't) works both ways.
> >
> > By the way, I still need zone 40 on 80m for my 5BWAZ.  When the auroral
> oval
> > recedes in a couple of years.....
> >
> > You'll love the instant direction switching of a 4 square.
> >
> > de Paul, W8AEF
> >
> >
> > ----- Original Message -----
> > From: PY2YP <[email protected]>
> > To: <[email protected]>
> > Sent: Sunday, January 06, 2002 8:45 AM
> > Subject: [80m] 4 square
> >
> >
> > > Hello All,
> > >
> > > Has anybody here using 4 square? I'm working on my own and
> >
> >
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