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Re: [TowerTalk] Please Help Me Decide on a Tribander or Monobanders

To: chetmoore@cox.net
Subject: Re: [TowerTalk] Please Help Me Decide on a Tribander or Monobanders
From: k2qmf@juno.com
Date: Fri, 19 Apr 2013 11:53:33 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Chet,

He was looking at the C19XR not the C31.
The C19 has a 19 foot boom!
The SkyHawk out performs the C19 hands down..
And much better constructed and less expensive to boot...

73,
Ted  K2QMF



On Thu, 18 Apr 2013 19:46:26 -0400 "Chet moore" <chetmoore@cox.net>
writes:
> Ted,
> 
> I may have missed something and there may be several models of the 
> skyhawk
> that I don't know about but the K7LXC/ N0AX  tribander report rated 
> the C31
> considerably Higher than the skyhawk but did give it an "honorable 
> mention".
> Further, the  Skyhawk tested in the tribander report  has a 24 foot 
> boom as
> opposed to the  31 foot boom on the  C-31.  I think you have it 
> right about
> Pricing though.
> 
> For Wayne, do yourself a favor and read the K7LXC tribander report.  
> It does
> not cover the StepIR as none was available at the time the
> Testing was done. 
> 
> 73
> 
> Chet N4FX
> 
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf 
> Of
> k2qmf@juno.com
> Sent: Thursday, April 18, 2013 7:02 PM
> To: rthorne@rthorne.net
> Cc: towertalk@contesting.com
> Subject: Re: [TowerTalk] Please Help Me Decide on a Tribander or 
> Monobanders
> 
> 
> Go for the SkyHawk tribander.
> Much better than the Force 12 and less expensive too...
> Longer boom etc.
> 
> 73,
> Ted  K2QMF
> 
>  
> On Thu, 18 Apr 2013 17:24:31 -0500 Richard Thorne 
> <rthorne@rthorne.net>
> writes:
> > I sure like my C31XR at 79' with a Delta 240 mounted 10' above it. 
> I
> > 
> > plan on changing out the 240 with a Delta 230/240  and lower it to 
> 
> > about 7' above the C31xr then add a WARC 2/2 at the 10' level.  
> That 
> > will give me a rotatable 10 through 40 solution.
> > 
> > I also have a C3 tribander (going on 17 years old) mounted on a 
> > rotatable swinging side gate at 40'.
> > 
> > I really like the F12 antennas, instant band change and made in 
> > America.
> > 
> > Rich - N5ZC
> > 
> > 
> > On 4/18/2013 4:06 PM, Wayne Willenberg wrote:
> > > My 86 or 89 foot crank-up tower project seems to be progressing
> > through my
> > > County review boards.  So now I am getting really excited for 
> my
> > first
> > > tower.
> > >
> > > I am now in ham nirvana because I have to start making up my 
> mind
> > on which
> > > antenna(s) to put on the 15' mast.  Here is my first dilemma.  
> > Should I put
> > > up a tribander (10, 15 and 20M) or 3 monobanders.  My intuition
> > said there
> > > was no way a tribander with the same 20M boom length could beat 
> 3 
> > > monobanders having a 20M antenna with the same boom length.
> > >
> > > So, just as an exercise, I looked at Force 12 antennas.  (I am
> > not
> > > endorsing Force 12 antennas, although they do seem to have a 
> good 
> > > reputation.  I am also aware that the performance specs of
> > antenna
> > > manufacturers need to be taken with a grain of salt -this is 
> not
> > meant to
> > > be a criticism of Force 12.)
> > >
> > > I started with the Force 12 model C-31XR tribander.  It has 14
> > elements on
> > > a boom length of 31', a wind load of 10.7 sqft and published
> > figures of:
> > >
> > > 20M gain: 14.0dBi, a F/B of 20dB,
> > >
> > > 15M gain: 14.3dBi, a F/B of 22dB, and
> > >
> > > 10M gain: 15.6dBi, a F/B of 21dB.  Published price: $2,970
> > >
> > > Then, I looked for monobanders from Force 12 that had a boom
> > length for the
> > > 20M monobander close to the C-31XR and a gain in the vicinity 
> of
> > the of the
> > > tribander for each of the 3 bands.  Here is what I found:
> > >
> > > EF-420 (20M with 4 elements) has a boom length of 30', a gain 
> of
> > 14.5Dbi,
> > > a  F/B of 22dB, a wind load of 5.5 sqft, and a cost of $1,300.
> > >
> > > EF-415 (15M with 4 elements) has a boom length of 20', a gain 
> of
> > 14.6Dbi, a
> > > F/B of 22dB, a wind load of 2.8 sqft, and a cost of $869.
> > >
> > > EF-510 (10M with 5 elements) has a boom length of 18', a gain 
> of
> > 15.1dBi, a
> > > F/B of 23, a wind load of 2.5 sqft, and a cost of $799.
> > >
> > > The total wind load of the 3 monobanders is 10.8 sqft and a 
> total
> > cost of
> > > $2,968.
> > >
> > > So, at first glance, the price and wind load of the tribander is 
> 
> > > practically the same as the sum of the 3 monobanders.  There is 
> no
> > more
> > > than an additional 0.5dB of gain (and 0.5 dB loss of gain on 
> 10M)
> > with
> > > monobanders;  a gain of 2dB F/B (and 2dB more F/B on 10M) for
> > monobanders.
> > >
> > > However, I am aware that there will be a degradation of the
> > performance of
> > > at least the middle monobander if I put 3 of them, in a 
> Christmas
> > tree
> > > fashion, on a 15' mast.  I haven't been able to find a good
> > discussion of
> > > the amount of degradation-even the 22nd Edition of the Antenna
> > Book has
> > > only a few words to say about this.  Please direct me to a
> > discussion of
> > > this topic if you know one.  I may have to model these antennas 
> on
> > EZNEC to
> > > see the impact of 3 antennas confined to a 15 foot mast.
> > >
> > > On the other hand, there has to be a compromise when 3 antennas
> > are mounted
> > > on a single boom.
> > >
> > > I would really appreciate your help in finding all of the specs 
> I
> > should be
> > > looking at in making this decision.  Any other comments that 
> would
> > push me
> > > one way or the other would also be appreciated.
> > >
> > > Please help me with my first tower!
> > >
> > > 73, Wayne KK6BT
> > > _______________________________________________
> > >
> > >
> > >
> > > _______________________________________________
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> > > TowerTalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > >
> > 
> > _______________________________________________
> > 
> > 
> > 
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> > 
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