Thanks for the valuable information.
I did receive some personally notes not shared here on Topband, thanks for the
help and the kind words. One indvidual specifically asked If I would share my
experience in some sort of presentation about building remote stations, he was
interested in the logistics from finding land to local zoning and the actual
build. I never thought about doing a presentation but it was an intriguing
inquiry, I did send him an album in chronological order of pictures and video
(drone) two of the many remote stations we have built the past few years. Both
albums have the start to finish…actually we are never really finished!. With
that said, here is the two albums if others are interested.
W1/Eastport https://goo.gl/photos/hEX1A4UR6wC6Lopp7
<https://goo.gl/photos/hEX1A4UR6wC6Lopp7> 63/ac
W1/Lubec https://photos.app.goo.gl/oFEmGbpA3eWo8D143
<https://photos.app.goo.gl/oFEmGbpA3eWo8D143> 20/ac
So, building a remote station 500 miles away from my home-base is nothing new
to me! While I’m uncertain if my new personal QTH with nearby marsh will have
any effect on the low band antennas, I pretty optimistic the station will play
regardless. :)
Thanks again,
Ray Higgins
W2RE.com
> On Apr 20, 2019, at 4:16 AM, shristov <shristov@ptt.rs> wrote:
>
>> donovanf@starpower.net wrote:
>
>> The classic source for Fresnel zones as they apply to HF site
>> selection is NBS Technical Note 139:
>> https://nvlpubs.nist.gov/nistpubs/Legacy/TN/nbstechnicalnote139.pdf
>
>
> This indeed is a classical source, but it should be noted that the derivation
> assumes that the elevation angle actually used for communication
> is equal to the elevation angle of the peak of lowest ground reflection lobe.
>
> This may or may not be the case.
>
> In amateur operation, communication is often done using elevation angles
> well below the peak of the lowest lobe, because of inability to erect very
> high antennas.
> In such cases, the first Fresnel zones extends much further than the
> equation 3.4-4 predicts. Correct formulas may be derived using the same
> procedure, while separating communication angle from lobe peak angle.
>
> Using vertical antennas additionally complicates matters.
> I am not aware of any work on this topic.
>
>
> 73,
>
> Sinisa YT1NT, VE3EA
>
>
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|