[MAMS] How weather affects Tropo conditions

[Dave Sublette]

Uh ....?  I think you have given an excellent answer, but to the wrong 
email :-)

Dave


On 1/9/2014 11:02 AM, Dr. Gerald N. Johnson wrote:
> The program ele.bas based on DL6WU data from G3SEK or now GM3SEK's 
> website works for me. My last 432 yagis give more gain on the CSVHF 
> antenna range than computed. Its been around a long time but DL6WU did 
> it right. It is a dos program but I'm running it in XP using 
> gwbasicwin.exe. If you can't get those from GM3SEK, I can put the on 
> my server for a bit. I can't help for mac.
>
> The DL6WU technique is to make a two element yagi, reflector and 
> driven element with an adjustable gamma match for the driven element. 
> The mount the element length without boom insulated (like a foam boom) 
> fairly close to the driven element, then tune the gamma for a perfect 
> feed match. Replace the insulated element with the desired boom and 
> element mount and trim the through the boom element until it give the 
> same impedance match without changing the gamma. Using the two element 
> yagi as a measuring tool for the reactance of the director being 
> tested. And his antenna designs are based purely on a smooth 
> distribution of changes in director reactance going from the driven 
> element to the front director. They are not randomly compute optimized 
> and so are most tolerant of length errors compared to the tightly 
> optimized yagi where the optimization may have gained a dB of gain at 
> the cost of higher side lobe amplitude.
>
> 73, Jerry, K0CQ
>
> On 1/9/2014 8:57 AM, Zack Widup wrote:
>> That would be very interesting! Let me know if you find it.
>>
>> There's something I've been looking for, too. I recently saw an 
>> article in
>> a proceedings or compendium that gave a way to calculate element length
>> correction factors for elements going through metal booms. I have seen
>> other articles on this but I only want the article that has been in a
>> proceedings or compendium in the last year or two. Maybe one of the 
>> recent
>> ARRL antenna compendiums? I just can't remember where I saw it.
>>
>> 73, Zack W9SZ
>>
>>
>>
>
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