[amsat-bb] Re: [PNWVHFS] 1.2ghz antenna location

[Edward Cole]

Writing this late at night....I wrote it backwards.

Obviously the 1.2G yagi will be inside the aperture of the HF quad, 
so try to keep the 1.2G yagi away from the quad and dish by the 
stacking distance of the  1.2G yagi to least impact its 
performance.  The quad probably will not mind the presence of the 
yagi much.  The 3-foot dish is a bigger item.

sorry,
Ed - KL7UW

At 11:28 PM 1/13/2008, Edward Cole wrote:
>When stacking antennas  within the aperture of another then one 
>should try to keep the lower frequency antenna out of the aperture 
>of the higher frequency antenna.  Use the stacking dimension of the 
>1.2 G antenna as minimum spacing.  If you do not know what that is 
>then use half the boom length as min spacing.  I would use that also 
>to keep the dish from affecting the pattern of the 1.2G antenna.
>
>Another goal is to try not to place booms parallel to a member of 
>the lower freq. antenna as this may cause coupling and distortion or 
>detuning of the lower freq. antenna.  This would indicate that you 
>should mount the 1.2G yagi pointing in the same direction as that 
>places the boom perpendicular to the quad loops.
>
>I think there is some info on stacking VHF antennas on the Directive 
>Systems website.
>73 Ed - KL7UW
>
>At 10:51 PM 1/13/2008, w7lrd at comcast.net wrote:
>>Hello
>>I will be mounting my 22 el 1.2Ghz yagi "inside" my HF 20,15, &10 
>>meter quad.  Has anyone tried something like this or even 
>>similar?  If I mount it up near the top of the mast is might be 
>>faily close to my 10M driven loop.  I also am considering mounting 
>>it 90 degrees to the quad boom and just figure that in whe aiming 
>>the short yagi.  So what would be the closest I want the yagi to be 
>>to any of the HF wires?  Part of the space inside the quad is taken 
>>up by a 3 foot primestar dish for 2.4 Ghz.  So the antenna 
>>placement "up there " is getting a bit crowded.  I want to try not 
>>to degrade 1.2 or my HF suff.  The height will be about 50 feet.
>>As Always- Thanks
>>
>>--
>>73 Bob W7LRD
>>"Somewhere, something incredible is waiting to be known"
>>Carl Sagan
>>
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>
>73,
>Ed - KL7UW
>======================================
>  BP40IQ   50-MHz - 10-GHz   www.kl7uw.com
>144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
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>======================================

73,
Ed - KL7UW
======================================
  BP40IQ   50-MHz - 10-GHz   www.kl7uw.com
144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
DUBUS Magazine USA Rep dubususa at hotmail.com
======================================