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Re: Topband: [Bulk] Top Loading wires

To: Charlie Cunningham <charlie-cunningham@nc.rr.com>, 'Grant Saviers' <grants2@pacbell.net>, 'Larry - K1UO' <k1uo@tds.net>, 'Topband Reflector' <topband@contesting.com>
Subject: Re: Topband: [Bulk] Top Loading wires
From: HAROLD SMITH JR <w0rihps@sbcglobal.net>
Reply-to: HAROLD SMITH JR <w0rihps@sbcglobal.net>
Date: Wed, 4 Feb 2015 10:48:14 -0800
List-post: <topband@contesting.com">mailto:topband@contesting.com>
The tower is 90 feet, not 50 feet.


On Wednesday, February 4, 2015 12:11 PM, Charlie Cunningham 
<charlie-cunningham@nc.rr.com> wrote:
 


Gee, I surely agree with Grant, Larry!  I've used EZNEC for MANY years, with 
great results, and I've designed, built, tested and measured many wonderful 
EZNEC designs - including some really complex "killer" antennas!


I do think that 28' top loading wires will be WAY TOO SHORT  atop 50 ft. of 
Rohn 25! More like 50-70' will be needed to resonate that tower. You will 
probably do just as well with TWO top-loading wires in a Tee configuration! The 
point is for the top-loading wires to extend the tower to 1/4 wave resonance on 
160.  Of course you could make an excellent 80m antenna with the 50' tower and 
some modest top-loading wires approaching the length that you are considering. 
GL!

If you are going to be experimenting with low-band antennas, EZNEC is a GREAT 
investment

73,
Charlie, K4OTV                

-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Grant Saviers
Sent: Wednesday, February 04, 2015 11:28 AM
To: Larry - K1UO; Topband Reflector
Subject: Re: Topband: [Bulk] Top Loading wires

With an insulated tower, the cheapest EZNEC and other free NECs will yield good 
results.  Would you rather climb, cut, and trim a few times or spend $89 to get 
EZNEC?  Simple to learn.  And the demo version is free  eznec.com

Grant KZ1W
no affiliation, just a long term happy user

On 2/4/2015 7:27 AM, Larry - K1UO wrote:
> Could someone tell me the length of top loading wires (4 wires planned) 
> needed to add to the top of a base insulated 90 foot Rohn 25g tower to 
> maximize the radiation resistance on 160 meters.  I understand there is a 
> point of diminishing returns on the top loading lengths.  The 4 wire angles 
> will be around 45 degrees or as close as possible.    If I knew how to model 
> ,or even had a modeling program, I would attempt this already relatively 
> simple task to many.
>  From 50+ years of practical experience, I am ‘guessing’ maybe 28 feet long 
> each?
>
>
>
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