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

Wed Feb 6 10:11:02 EST 2013

Hi All, eme doppler shift varies directly with frequency. Maximum at 21MHz  
is + 58 Hz at moon rise and -58 Hz at moon set for latitudes near the 
equator  and virually 0 Hz at the poles

The majority of the doppler shift is caused by earth rotation and is  
related to station latitude. 

73,
Gerald K5GW

In a message dated 2/6/2013 9:01:26 A.M. Central Standard Time,  
tonno.vahk at gmail.com writes:

There  was no noticable shift. I guess that is the case on  HF.

73
tonno

-----Original Message-----
From: TowerTalk  [mailto:towertalk-bounces at contesting.com] On Behalf Of 
Hans  Hammarquist
Sent: Wednesday, February 06, 2013 5:51 AM
To:  towertalk at contesting.com
Subject: [TowerTalk] Fwd: 15m monster finally up -  EME and Video

How much was the frequency shift due to the moon's  movement?

Hans - N2JFS

-----Original  Message-----
From: Tõnno Vähk <tonno.vahk at gmail.com>
To: towertalk  <towertalk at contesting.com>
Sent: Tue, Feb 5, 2013 8:49 am
Subject:  Re: [TowerTalk] 15m monster finally up - EME and  Video

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 at gafm.ee]
Sent: Tuesday, September 25, 2012  9:48 PM
To: towertalk at contesting.com; cq-contest at contesting.com
Cc:  es5tv at 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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