Gary,
I would put the 40 beam above the WARC beam (higher is better). The M2
rotator is a good choice. Separation of 10 feet should be adequate without
having to place the beams in separate directions. Leave the remainder of
the mast in the tower to avoid excessive wind load.
I would also keep the A4S in place at 45 feet and stack it with the upper
beam while on 20-15-10. This will give you the best of both worlds (high
and low elevation) during contests and DX hunts. You can rotate the A4S
using a simple rotator with a swing arm, or a ringrotor (more expensive), or
fix it toward Europe and stack only for operation to the east. There is a
saying: Once you stack, you won't go back. :)
73, Keith NM5G
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Gary Stone
Sent: Monday, April 18, 2005 12:46 PM
To: towertalk@contesting.com
Subject: [TowerTalk] new tower / antennas questions
Hello from N5PHT,
I am N5PHT, Gary, writing from Savoy, Texas. I have a tower and new
antennas project in the works and it is exciting to me but I have some
questions. I am putting up a 45G at 80 feet. The antennas on top of the
beam: Optibeam 17-4 and the WARC-7 above the big Optibeam.
My first question is about separation? I have read that you can put them
closer if you put one of them 90 deg out of the other. I have a
22 foot mast and will be using the M2 2800DC with two thrust bearings so
that will leave about (?) 18 feet above the top of the tower. What
separation would be good to have both antennas aimed the same direction? I
would think 10 to 12 feet would be fine? If 10 feet is ok that would allow
me to mount the rotator a bit further into the tower?
Secondly, does anyone have experience with putting together the OB17-4 (or
the WARC7 for that matter)? The OB17-4 weighs in at a little over 200 lbs
and has a 39 foot boom. The WARC-7 is much smaller. Any tips on either of
these antennas appreciated?
Third, what about antenna height? I am thinking that 80 feet is much better
for the 3 elements on 40 meters but is that too high for 20 or
15 meters? I realize many hams put up antennas very high, well over 100
feet so I am thinking 80 feet is no problem for any band 10 - 40 meters?
Lastly, any speculation on the improvement this will be over my Cushcraft
A4S at 45 feet for 10, 15 and 20 meters? I am looking forward to have some
gain in other bands, especially 40 meters!
73 de N5PHT, Gary
<><><> Gary Stone - N5PHT <><><>
<> 347 CR 1250 <>
<> Savoy, Texas 75479 <>
<> UNITED STATES OF AMERICA <>
<> (903)965-7724 <>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|