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Re: [TowerTalk] 15m monster finally up - EME and Video

To: "TowerTalk@contesting.com" <TowerTalk@contesting.com>
Subject: Re: [TowerTalk] 15m monster finally up - EME and Video
From: Drax Felton <draxfelton@gmail.com>
Date: Tue, 5 Feb 2013 09:44:06 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
How do you know you didn't ionosonde yourself?  




Sent from my iPhone

On Feb 5, 2013, at 8:49 AM, Tõnno Vähk <tonno.vahk@gmail.com> wrote:

> Hi,
> 
> 
> 
> After two fruitless attempts at moonrise I got EME QSO with myself done
> during moonset.
> 
> 
> 
> Here is the video of the best minute out of ca 10 minute period the signals
> were audible with strong QSB on January 13th, from 1615 to 1625z ca 2 hours
> after sunset:
> 
> 
> 
> <http://youtu.be/QCP0kisTbME> http://youtu.be/QCP0kisTbME
> 
> 
> 
> Moon was setting at ca 243 degrees azimuth and the signals were audible
> while the moon was from 3.3 to 2.2 degrees of elevation peaking at 2.6
> degrees. Antenna was pointing within 3 degrees of the correct direction.
> Radio: FTDX5000 + ACOM2000A.
> 
> 
> 
> It is noteworhty that the band was not 100% closed as even some SA signals
> were heard. Also the amazing strength of the signals at expecially the 3rd
> time the signals come back is probably also attributable to some ground gain
> at this elevation.
> 
> 
> 
> I wish I had also tried SSB and maybe the 4 high tribander stack for
> comparison but was too excited to remember. Should also try if changing the
> radiation angle to say even 30 degrees would allow hearing moonbounce from
> that elevation. Next timeJ
> 
> 
> 
> Now all I have to do is to find someone interested in attempting real 15m
> EME QSO (anyone done that before?) who would have coinciding sunset/sunrise
> and high gain antenna on 15m.
> 
> 
> 
> Can anyone recommend a good program that would picture moon grayline (like
> DX Atlas for sun) that would enable to easily identify possible paths for
> EME at any given time/day?
> 
> 
> 
> Here is also the high resolution video of the tower erection put together by
> ES5PC. It also includes the very first QSO with the new stack with Paul,
> K8PO:
> 
> 
> 
> http://youtu.be/Z9fDlbIFhMs
> 
> 
> 
> I have also made tests regarding the use of different elevation angles (by
> shifting the antenna pairs 180 degrees out of phase) and the first results
> are very interesting. Proving that for DX normally the lowest 4 degrees is
> best but even for DX sometimes 7 or 10 degrees is noticably better bringing
> an otherwise not audible signal out from the noise. The same is true about
> some EU signals that peaked at 15 degrees while almost not being audible on
> low angles. So I will do more testing but I am more convinced now that even
> in contest the switching of angles might be useful trying to get a weak
> signal out from the noise and high angles are sometimes very necessary.
> 
> 
> 
> 73
> 
> Tonno
> 
> ES5TV
> 
> 
> 
> 
> 
> From: Tõnno Vähk [mailto:tonno.vahk@gafm.ee] 
> Sent: Tuesday, September 25, 2012 9:48 PM
> To: towertalk@contesting.com; cq-contest@contesting.com
> Cc: es5tv@erau.ee
> Subject: 15m monster finally up
> 
> 
> 
> I am happy to inform all friends that a project of last 4-5 years was
> completed during the last weekend at ES5TV KO38CS central ES QTH and a
> double H frame on 15m was finally erected what is probably one of the
> biggest 15m setups in the world today.
> 
> 
> 
> See the full 2-day gallery at:
> 
> http://pontu.eenet.ee/es5tv/
> 
> 
> 
> Go to the last 16th page if you wish to see the final product right awayJ
> 
> 
> 
> 70 meters high tower carries 8 5-element 15m yagis as pairs separated
> horizontally by 12 meter distance and vertical stacking is 14 meters. The
> heights of the antenna pairs are 64, 50, 36 and 22 meters.
> 
> 
> 
> Antennas are Optibeam OB5-15:
> 
> http://www.optibeam.info/index.php?article_id=76
> <http://www.optibeam.info/index.php?article_id=76&clang=1> &clang=1
> 
> 
> 
> Tower is produced by 4O3A/YT3M: 
> 
> http://www.4o3a.com/index.php?option=com_content
> <http://www.4o3a.com/index.php?option=com_content&view=category&layout=blog&;
> id=99&Itemid=499> &view=category&layout=blog&id=99&Itemid=499
> 
> 
> 
> Model shows ca 16 dbd free space gain and almost 24 dbi gain at 4 degrees
> over real ground. Beamwidth is less than 30 degrees. Testing has been so far
> limited but the results confirm exactly the modelling results. Pattern
> measured with signal generator and SDR was almost identical to what the
> computer suggests and signal levels drop ca 12 db when antenna is 20 degrees
> off and already 20 db when 25 degrees off the correct direction. There is
> huge -50db+ null at 90 degrees confirmed with real measurements (!) and ca
> -20-30 db signal drop on the other directions.
> 
> 
> 
> First comparisons with my best antenna so far (4 high tribander stack) show
> ca 10 db advantage to US when pointed right. That is huge of course.  At the
> same time east coast and west coast can’t be covered with one directionJ
> 
> 
> 
> The stack will have phase switching capability which allows any pair of the
> 4 to be switched out of phase to change the radiation angle. Pre-configured
> steps are 4, 7, 10, 15, 30 degrees while maintaining most of the gain as all
> antennas are always connected. The phase switching is not yet connected but
> will be very interesting to see the results and to get some real insights
> into how the different angles play.
> 
> 
> 
> We briefly tried to hear the moonbounce when the moon was on horizon but did
> not succeed yet. But 15m was wide open and signals probably did not
> penetrate the ionosphere. I still hope to be able to complete some EME QSOs
> with the stackJ
> 
> 
> 
> CQWW RTTY on the coming weekend will be the first contest for the monster.
> Let me know how ES9C will sound on 15 meters. As the rotating is still
> manual will keep it either to US or JA.
> 
> 
> 
> 73
> 
> Tonno
> 
> ES5TV
> 
> 
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> 
> 
> 
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