Hi Gary and Bill W4AN, Thanks for your comments and to everybody else as
well. According to the modelling so far the F/B and SWR are not badly
affected by the Yagi interaction, and the gain drop is not something that
might be easily noticed. But i don't want to throw away the gain difference
between a 5el and a 3el by interaction.
I don't use YO so i can't see if it is possible to retrieve any lost gain do
to it. Short of having separate 15 and 10m towers i think I'll settle for
the 15&10m Yagis at right angles. I don't like the idea of a 4el 10m
flapping around
on a 12ft stub mast in a 125mph gust!!. 73 Clive GM3POI
-----Original Message-----
From: Gary D Elliott <k7ox@pipeline.com>
To: Clive Penna <clive@gm3poi.prestel.co.uk>; TowerTalk
<towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: 16 February 1999 00:40
Subject: Re: [TowerTalk] Yagi Separation
>Hi Clive
>
>All I can do is give you real life results in stacking a 10 and 15 meter
>monoband beam. I have a 5 element Hy-Gain ten meter beam stacked 9 feet
>over a 5 element Hy-Gain 15 meter beam and no problems. I first put up the
>ten meter beam and ran checks such as SWR and FB and used it for a while.
I
>then added the 15 meter beam right at the top of the tower and did the
same.
>All I can tell you is that the ten meter beam did not change any and seems
>to work as well when it was up by itself. I have nothing to compare the 15
>meter beam with because it was never up by itself. However, it feels
right,
>FB is good and SWR is fine. These antennas have been up for over ten years
>and have had no problems. For what ever it is worth, this is the results I
>had.
>
>73 Gary
>
>
>-----Original Message-----
>From: Clive Penna <clive@gm3poi.prestel.co.uk>
>To: TowerTalk <towertalk@contesting.com>
To: <towertalk@contesting.com>
>Date: Monday, February 15, 1999 7:44 AM
>Subject: [TowerTalk] Yagi Separation
>
>
>>
>>Hi, I'm currently trying to evaluate the effect of various spacings on a
>15m
>>4el and a 10m 4el. I wonder what others have found.? I have modelled both
>>with each antenna being the upper one to see if the 15m screens more than
>>the 10. So far it appears that the spacing has to be 10ft for a 1db
>>degradation in the 10m Gain. so ideally 12ft. On putting the two antenna's
>>at right angles they can be separated by 6ft without a gain drop off. Has
>>anyone confirmed this?. I can't see the point of loosing the gain in a
>lack
>>of vertical spacing. So i'm minded to have them at right angles, any
>>comments. Clive GM3POI
>>
>>
>>
>>
>>--
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>>
>
>
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