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[TowerTalk] 40 m beam at 16 m high (summary) LONG

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Subject: [TowerTalk] 40 m beam at 16 m high (summary) LONG
From: jurgen.geldhof@skynet.be (Jurgen Geldhof)
Date: Wed, 30 Dec 1998 11:00:36 +0100
Hi,

Sorry for the delay but here's the summary of the answers I received to my
question whether it would be worth the trouble (and money) to put up a 40 m
2 elt. beam at only 16 m. high.

*****

I had a 40-2CD before changing to Force12 Magnum, and it was on my
telescopic Versatower at 20 meters. One morning on 40 CW when I worked a
ZL2 long path I asked for a comparative report when I reduced the height to
10 meters. It was abt 3 dB.

I would invest. It made 40 almost sound like  20  !     hi


73   Rag  OZ8RO

*****

It all depends upon how high the inverted Vee you are now using is. 
Inverted Vee's are effectively lower than dipoles at the apex height and
have a higher angle of radiation since more of it is closer to the
ground.  A high dipole is hard to beat.  If you put up a 2 element beam
at the same height of a dipole expect 3-5 db gain.  This is substantial.
Expect more with respect to an inverted Vee with it's apex at 16M.

There is another benefit that people seem not to discuss.  You can point
in in the desired direction and reject stuff off the back and sides of
the antenna.  This, I imagine is a great help in Europe and also a big
help in the summer with the QRN.  You can't work 'em if you can't hear
'em.  During contests, it can make a band useable and productive.

About 30 years ago I had a 2 element shortened 40 meter beam at about 12
meters high.  It did indeed outperform the wire antenna at about the
same height.  The difference seemed substantial.  

Is it worth the effort?  Maybe you should consider doing this is two
steps.  Replace your inverted Vee with a dipole at the apex height.  See
how that plays.  If you're still not satisfied -- go for the beam. 
Another option to consider is a rotary dipole for 40M.

I've settled on a rotary dipole at 23 meters here for 40 meters (half of
the 40-2CD beam you're talking about).  Compared to the dipole I
previously had at about 13M high, it's super.  Also it does reject some
signals off the side.  Maybe this is an option for you too.  It only
weighs about 3 kilo's but has considerable torque because of it's
length.  I have it "stacked" with my 4 element quad (actually, it is
only 1' above the boom and at right angles to it).  So far I've worked
279 countries with it on 40 meters over the past 2 years. 

I guess what I'm saying is that one might experiment with the cheaper
options first...

Good Luck, 73 and holiday greetings
Brian/K3KO

*****

It's worth it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   Try the beam
vertical and horizontal for interesting results.
-73-
Dave, K3BHJ.

*****

I think that putting up the 40-2CD at 16M high would probably not be
worth the effort.  Mine is at 22M and works very well.  I'd probably
try a sloper array or possibly a phased vertical array (if you have
the room available).  GL with the project.

Seasons Grettings!
73, Stew  K3ND

*****

A22MN  had  good results with his 402CD at 50 ft (15M).

A 4 square vertical array is another option if you have the space.
It would take approximately 30M  square for a full set of radials
under each element.

73 /  GL,  Tom  N4KG

*****

Jurgen,  Just for information.  In the CQWW CW contest a few years ago,
while living on a small city lot, I used the 402CD at 42ft. high.  I worked
126 countries in the contest.  It worked very well at that "low" height.
GL & 73, Mike K5NU

*****

I have been using 2 element short 40 meter beams at various
heights since 1966.  First the HyGain 402BA and later the 40-2CD.
At present my 40-2CD is at 50 meters and the 402BA is at 16
meters and I have relay switching.  There is several dB of
difference between the two antennas on DX and practically no
difference for W signals.  The difference shows up mainly on weak
signals and long path contacts where the higher antenna is best.
Before putting up the higher antenna I had a 40 meter dipole at
16 meters along with the 402BA and the beam was ALWAYS better
than the dipole.  Put up the beam, you will not be sorry.

George
W2VJN

*****

i had the same problem, and i talked to tom, n6bv, of force-12 about 
putting up a LOW (11m!) 2 el 40m beam.  he told me it would not be 
optimum, but would still outperform the inverted vee.

i bought one and put it up, and i'm very happy with it!  i wish it 
were 20 or 25 m high, but it still works very well (compared to the 
inverted vee)  i'm glad i did it!

73,

George T. Daughters, K6GT

*****

The 40 meter beam will work great at 16 meters.  I remember HB9RG had his
75
meter Create at only 16.5 meters and was loud on 75.  Mine is cranked down
to 12M but I worked a whole page of Europe a few weeks ago on 10.  Worked
many on 20 on first call all with exciter and 100W.

Go for it....will look for you on 40 SSB shortly.

Dave K4JRB

*****

A friend of mine, KI1G, is rebuilding his station.   For now, he could only
put his CC 40-2CD  at about 30 feet.   He reports surprising success with
it.   His results in CQWW CW  also speak well for the antenna at that
height.   For sure, higher would be better;  but if you can only put it up
16 meters, by all means, do it!

good luck &
73  James / k1sd

*****

Probeer geen 40m beam te doen werken op 16m hoogte.Zal werken als uw inv V.
Ik heb hier zelf een 40-2cd die op een hoogte staat van 28m.Heb ook een
vertikal die
op 2 meter hoogte staat .GEMIDDELD 1S punt verschil tussen deze 2 antennes.
Denk niet dat het de moeite waard is om al dat geld te spenderen aan
ant/motor .
Probeer eens een 1/4 sloper .Ik gebruik hier 3 x 1/4 slopers voor 80m en
werk ook alles
wat ik hoor (ook de verre DX).

tks 73/dx
on4ma
Marc ON4MA      

        Translation : Don't try to make a 40m beam work at 16 m high, it'll work
        as your inv. V.  I have a 40-2cd at 28 m high.  I also have a vertical 
at
        2 m high.  Average difference between both antennas is 1 S-point.
        I don't think it is worth to spend al this money to the antenna and
        rotator.
        Try a 1/4 wave sloper. I use 3 x 1/4 wave slopers on 80 m and work
        everything I hear (also the far DX)

*****

I had a KLM 2 el beam at 52 feet.  Wow!

In DX pileups it was a real advantage.

73 de John, WA5TWL

*****

Thanks to all for this bunch of information.  Anyone ever thougt of writing
a "Towertalk-book" with this kind of info ????   :-)

This afternoon I'll put up my first 1/4 wave sloper to do the first
comparative tests to my inverted V dipole.  Anyhow, if I go for the beam it
will be a project for my summer holidays, so still  6 months left to try
out the cheaper alternatives !

73 es all the best for 1999 !

Jurgen "Jo" Geldhof   ON4BCJ

jurgen.geldhof@skynet.be

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