[WARC] NVIS

[Dick Lindner]

Ah, the 105% reflector.  Yes, some of the data suggested a 
reflector/counterpoise at 2 feet above ground directly under the dipole.

Another interesting thing about the autotuner at the feedpoint was that 
if one were to make the "hot" side of the dipole 5% longer (one side 44 
feet plus 5%), the autotuner would be more reliable.  I have not quite 
figured out the why of that one!  Nevertheless, the idea of placing an 
SGC autotuner inside of a Rubbermaid kitchen pan so as to weatherize it 
is totally neat.  I believe Ed simply has his antenna inside the house 
therefore has no need to weatherize the black box.

Yes, do take time to read the data on the 88 foot length.  It is 
fascinating and pretty convincing.

Dick

Len Litvan wrote:
> Hi Dick,
>
> Thanks for pointing out the facts (facts....those nasty things!).  I 
> have been inundated with sources and advice about NVIS.  Guess I need 
> to find some time and study it all.
>
> The item in Ed's references which caught my attention had to do with 
> the option of inverted V vs. other physical layouts.  We had been 
> trying inverted Vs, and that's apparently not the best configuration 
> based on practical experience reported.
>
> Fifty feet per leg is a good dipole length for a shortened multi-band 
> antenna extending to 80 meters because it stays away from the high 
> impedance lengths on most bands.  Let me look again at what Dr. Ed 
> sent.  Maybe 88 feet is a dedicated answer for NVIS, which is strictly 
> an 80-40 meter option.
>
> Thanks again.   We are learning.
>
> Putting the pieces together, the next experiment might be 88 feet 
> flat-top dipole up 15 feet with a 92.4 foot (105%) reflector on the 
> ground underneath.
>
> Did you ever see the movie "Contact"????
>
> 73,
> Len  KC0RSX
>
> Dick Lindner wrote:
>> Am I missing something here?
>>
>> According to what I read, Ed gave the formula...88 feet - 2- 44 foot 
>> sections - dipole - at 15 feet elevation above ground - all kinds of 
>> data to back it up - tuner at the feedpoint - coax to transmitter...
>>
>> Data suggests that there is no such thing as a random length that 
>> works and that the optimum length for an 80-40 two-band is 88 feet.
>>
>> This sounds sassy and is not intended to be so.  Dick
>> _______________________________________________
>> WARC mailing list
>> WARC at lists.w0ne.org
>> http://lists.w0ne.org/cgi-bin/mailman/listinfo/warc
>>
>>
> _______________________________________________
> WARC mailing list
> WARC at lists.w0ne.org
> http://lists.w0ne.org/cgi-bin/mailman/listinfo/warc
>