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15M Antenna

Subject: 15M Antenna
From: RFPWR@aol.com (RFPWR@aol.com)
Date: Thu Jul 6 20:07:05 1995
Hi Sam:

Is this cq-contest reflector wonderful or what? There is a lot of information
lurking out there which one would never otherwise be able to tap!!

Without putting up additional towers or extending the present ones,  the
highest I can go with my 155CA is 70', assuming I dedicate the tall tower to
20 and 40M. 

So my options are limited to a range of 50 to 70'.  I haven't decided for
sure, but will probably opt to put the 155CA at 70', stacked above a 205CA. 

On my 100' tower, I will probably go with a stack of 205CA's at 100 and 50',
with the bottom fixed on EU. At 110' on that tower will go a 40-2CD, and will
probably put the other fixed on EU at 60' (phased).  At 115' or so I might
put the 105CA. 

On the tower vacated by moving the 155CA and 105CA, I think I will put the
TH7 up by itself at 60'. It is about 150' away from the other towers.

I toyed with the idea of taking down the 4el 20M quad because of the
difficulty in keeping it up on the Gulf Coast. But it looks so good up in the
air that I will probably also make it 4 elements on 15 and 5 on 10, and leave
it up as long as it survives. 

The above plan was developed after considering all the input provided by so
many knowledgeable people on the reflector. It might not make the biggest
CONTEST
station around, but should provide all the fun I can handle.

73 and cul 

Chas N8RR 

>From Rich L. Boyd" <rlboyd@CapAccess.org  Fri Jul  7 00:34:55 1995
From: Rich L. Boyd" <rlboyd@CapAccess.org (Rich L. Boyd)
Subject: Tower Mast Installation
Message-ID: <Pine.SUN.3.91-FP.950706193250.8297E-100000@cap1.capaccess.org>


How to install long mast in tower:

a.  Put it inside the tower when you install the first 1, 2, or 3 
sections, than raise it through the middle of the tower to its final 
position when the tower is done (as opposed to hauling it all the way to 
the top of the tower on the outside when the tower is done).

b.  Use the ginpole you've been using to raise tower sections, tied onto 
the mast above the center of gravity, and lower it through the thrust 
bearing.

c.  On erector-set type towers, diagonals and horizontals can be taken 
off and the mast can be "melted into" the side of the tower.  This method 
was used by N3RR nearby in MD recently, and I think is used by W3LPL and 
others using these types of towers.

Rich Boyd KE3Q


>From kf3p@cais.cais.com (Tyler Stewart)  Fri Jul  7 01:21:45 1995
From: kf3p@cais.cais.com (Tyler Stewart) (Tyler Stewart)
Subject: Tower Mast Installation
Message-ID: <199507070021.UAA27614@cais.cais.com>

>Hola!
>
>I'm putting up 70' of Rohn 45 for my contest station.  I'd like to mount a
>shorty forty 10 to 12 feet above my TH6 on a 15 foot mast, with 3 to 5 feet of
>said mast below the top of the tower.  A thrust bearing on top of the
tower, and
>another a couple of feet below the top will be used to keep the mast stable.
>
>I've got a question for the cq-contest tower gurus:
>
>How do you install a 15' mast safely without using a crane?
>
>Many thanks and 73,
>Charlie  KD5PJ/9       ocker@chasind.com

If you haven't put the tower up yet, build the tower around the mast ie. put
the mast inside the first couple of sections.  Then when you are done with
the tower, just haul it up inside the tower, thru the rotator plate and  thrust
bearing!

73, Tyler KF3P


>From Frank Donovan <donovanf@sgate.com>  Fri Jul  7 01:39:38 1995
From: Frank Donovan <donovanf@sgate.com> (Frank Donovan)
Subject: Tower Mast Installation
Message-ID: <Pine.OSF.3.91.950706203703.26581C-100000@jekyll.sgate.com>

Hi Charlie!
The easiest way is to install it in the bottom section as u are building the
tower, then pull it up thru middle of the tower to its final position 
when ur finished building the tower!
Another possibility is to use a gin pole, u can safely tie onto the mast 
6 feet down from the top, or even further if u add a weight to the bottom 
of the mast to keep it vertical during the lift!
73!
Frank
W3LPL

On Thu, 6 Jul 1995, Charlie Ocker wrote:

> Hola!
> 
> I'm putting up 70' of Rohn 45 for my contest station.  I'd like to mount a
> shorty forty 10 to 12 feet above my TH6 on a 15 foot mast, with 3 to 5 feet of
> said mast below the top of the tower.  A thrust bearing on top of the tower, 
> and
> another a couple of feet below the top will be used to keep the mast stable.
> 
> I've got a question for the cq-contest tower gurus:
> 
> How do you install a 15' mast safely without using a crane?
> 
> Many thanks and 73,
> Charlie  KD5PJ/9      ocker@chasind.com
> 

>From Frank Donovan <donovanf@sgate.com>  Fri Jul  7 02:10:49 1995
From: Frank Donovan <donovanf@sgate.com> (Frank Donovan)
Subject: High vs Low
Message-ID: <Pine.OSF.3.91.950706204317.26581D-100000@jekyll.sgate.com>

Ed,

I must say that I disagree with almost everything in your message...

Rather than getting into a lengthy technical debate on each point, I'll 
simply point out that the top performing contest stations use horizontal 
polarization, almost exclusively, on the 40-10 meter bands.  The difficulty 
with vertical polarization is that the efficiency of the vertical ground 
reflection is very poor at almost all locations, and a phase shift in the
vertically polarized ground reflection significantly degrades low angle 
radiation (the so called Brewster Angle).  Because I have four 
200 foot towers, I also use horizontal polarized 2L quads EXCLUSIVELY for 
transmitting on 80 meters!  Ask any European, Asian or Pacific contester
about the W3LPL 80 meter signal...  And look at the W3LPL 80 meter DX 
contest scores...  More often than not over 100 countries in one weekend.
(feel free to ask any W3LPL operator about how much power we run, 
never more than 1500 watts, in fact the station is incapable of QRO).

Many successful contest stations have very high antennas available!  
The W3LPL high antennas (3L 40M at 190 ft, 5L 20M at 190 ft, 6L 15M at 
190 ft and 7L 10M at 190 ft) can AND OFTEN DO produce results that are 
incredible compared to my more typical contesting Yagis (W3LPL 5 over 5 on 
20M at 50 and 100 ft on 20M and 15M and a 3L 40M full size at 100 ft).  These 
extremely high antennas have made the winning difference in more than one 
DX contest.  I'll also note that there  have been occasional (but only 
occasional) DX contests when the very high Yagis have not been a 
significant factor in the W3LPL DX contest scores.  

Ed, in my reply I've tried to avoid the "blowtorch" reply you feared, and 
I've confined my comments to actual experiences of the W3LPL DX Contest 
team, as documented in the pages of CQ and QST for the past 25 years...

Put up a 200 foot tower and experience the true meaning of low angle DX!

73!
Frank
W3LPL

On Thu, 6 July 1995, Edward W. Sleight wrote:

> To sum it up, the old "higher the better"  came from days long gone 
> when we simply didn't know any better for lack of proper 
> instrumentation.
> 
> 
> OK, light your blowtorches....73, Ed K4SB
> 
> 

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