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Re: [TowerTalk] Antenna Modeling

To: Wes Stewart <wes_n7ws@triconet.org>
Subject: Re: [TowerTalk] Antenna Modeling
From: Edward Mccann via TowerTalk <towertalk@contesting.com>
Reply-to: Edward Mccann <edwmccann@yahoo.com>
Date: Fri, 13 Jul 2018 16:19:15 -0700
List-post: <mailto:towertalk@contesting.com>
Wes:
Standing by for your observations on and experiences with balanced tuners.
Ed McCann
AG6CX


Sent from my iPhone

> On Jul 12, 2018, at 6:12 AM, Wes Stewart <wes_n7ws@triconet.org> wrote:
> 
> I been reading this thread with interest and for no particular reason I'll 
> jump in here.
> 
> I've been modeling antennas since the ELNEC days. (I used Touchstone running 
> under DOS for circuit analysis forever ago.) But I've built antennas longer 
> than that, obviously without modeling. So I'm comfortable with both methods 
> and I believe there is a place for both.
> 
> "Trial and error" should probably be "trial and adjustment."  A simple 
> dipole, hung inverted-vee style in my case, installed in an available space, 
> is more quickly made operational by estimating length by formula, adding a 
> few inches (or feet depending on band) hanging it up, measuring the match and 
> shortening it appropriately. When you're done, you're done.  Was this a 
> "learning experience"?  Maybe a little to a beginner, but otherwise, not 
> particularly.  But so what, everything doesn't have to be a science project.
> 
> I've used the same method to build one of those antennas that according to 
> some, doesn't work; the parallel wire (fan), fed in the middle with coax+CMC, 
> inverted-vee style, 80 and 40 meter dipole, apex at 45'.  As some have noted, 
> it takes special care to model this and in my experience, it's hard to 
> account for every other variable, such as proximity to (unknown) ground, 
> support structures, other antennas, etc.
> 
> So, not realizing that it won't work, I did it anyway.  Seemed pretty simple 
> to me and while I am normally not a fan of anecdotal evidence, with years of 
> experience with this antenna, I'm okay with it.  My main activity is working 
> DX but with no obsession toward working every country on every band. One 
> hundred entities on each band suits me as success, more are just gravy.  That 
> said, using this, it can't possibly work antenna, in casual operation, I have 
> over 1,000 80-meter and 2,000 40-meter contacts with DX stations.
> 
> I'll address the balanced line feeder in another thread.
> 
> Wes  N7WS
> 
>> On 7/11/2018 9:29 PM, David Gilbert wrote:
>> 
>> 
>> Same here.  Trial and error may eventually work, but most likely you won't 
>> know why.  Modeling, especially if you investigate the currents and their 
>> phasing, will help you learn and understand why something might work or not 
>> work.  "Ham" radio doesn't mean being ignorant of the stuff behind what we 
>> do.
>> 
>> There are pitfalls with modeling of course, but doing things like a running 
>> a sensitivity analysis (tweaking dimensions to see if the changes make 
>> sense) can minimize that.  I learned more about antennas from playing around 
>> with EZNEC+ than I ever did from any other source.
>> 
>> 73,
>> Dave   AB7E
>> 
>> 
>> 
>>> On 7/11/2018 5:19 PM, Jim Brown wrote:
>>>> On 7/11/2018 5:08 PM, Dan Bookwalter via TowerTalk wrote:
>>>> I know everyone is onto modeling everything,  I am in the camp of , put it 
>>>> up , give it a try , dont like it , try again ...
>>>> We have lost so much of the "ham" part of ham radio... I used to , and 
>>>> still do , throw a wire out and see what you can do ... other than 160 and 
>>>> probably 80 , you can work a suprising amount of stuff ..
>>> 
>>> My view is completely the opposite -- to me, ham radio is studying the 
>>> fundamentals and using that knowledge to build our stations, including 
>>> antennas, that work better. Wandering around in the dark is not part of my 
>>> view of ham radio.
>>> 
>>> 73, Jim K9YC
>>> 
>>> _______________________________________________
>>> 
>>> 
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