[TowerTalk] 15m monster finally up

[K8RI]

On 9/25/2012 3:01 PM, n8de at thepoint.net wrote:
> Considering that 40m is 3 times 15m in wavelength +/- a smidge, looks
> like 210m tower to me.
> Gotta win the lottery two or three times to do that one!

That doesn't count having to build a new home well away from the airways 
to keep the FAA happy and in an area without tower height limitations. 
Yet stay some where near civilization.<:-))

Well, maybe a stacked pair.


73

Roger (K8RI)


>
> 73
> Don
> N8DE
>
>
> Quoting K8RI <K8RI-on-TowerTalk at tm.net>:
>
>> On 9/25/2012 2:47 PM, Tõnno Vähk wrote:
>>> 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/
>>
>> Impressive!
>>
>> I wonder how well that'd scale to 40 meters and what tower height would
>> be required.
>>
>> 73
>>
>> Roger (K8RI)
>>
>>
>>>
>>>
>>>
>>> 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&clang=1
>>>
>>>
>>>
>>> Tower is produced by 4O3A/YT3M:
>>>
>>> http://www.4o3a.com/index.php?option=com_content&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
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
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