[Towertalk] director rotation

[Mark]

Interesting discussion ... I have had aerials "malfunction" during winter
storms ... read, during contests .. and still work, but had no time to
analyze whether it was for the better or worse... "keep the rate up" -- HI
.. `tuther thing .. had a couple "TWIST" aerials years ago, on 6M .. as old
rusty remembers, one was and 11 el GOTHAM beam, other was Gonset, I believe
... anyway, there were various twisted element yagi design antennas, where
each element added a certain degree of  off-center until the whole enchilada
had made the 360 degree twist .. and mine seemed to work great... the best
of both worlds, probably not master of none....  when I put up a killer KLM
.. my twist, whichever I still had at the time, did not ever beat it...
although, sometime it was interesting that it would equal, with such an boom
length difference... and the KLM was slightly higher in altitude, so ...
bottom line, twist lost, but sometimes anomalies happen ... I don't think I
will be installing a 20M twist... Gads, too much like sticking a Quad on a
tower!  Tnx definitive info, Mike!  73 y'all .. Mark, AA6DX  CN70wt
----- Original Message -----
From: "Mike" <W4EF@dellroy.com>
To: "Bruce Makas" <k1my@msn.com>; "Towertalk submital"
<towertalk@contesting.com>
Sent: Saturday, May 11, 2002 10:44 PM
Subject: Re: [Towertalk] director rotation


> Coupling with respect angle is generally a function of square of the
> cosine of the angle between the two elements. Thus at 5 degrees
> offset, the coupling loss relative to perfect alignment would be
> around -0.03 dB. At 30 degrees offset, the coupling loss would
> be -1.25 dB, increasing to -3 dB at 45 degree offset.
>
> 73 de Mike, W4EF..................
>
> ----- Original Message -----
> From: "Bruce Makas" <k1my@msn.com>
> To: "Towertalk submital" <towertalk@contesting.com>
> Sent: Saturday, May 11, 2002 8:44 AM
> Subject: [Towertalk] director rotation
>
>
> > I have a KLM KT34XA. If the reflector were to rotate a lot on the boom,
> say
> > 30-45 degrees from horizontal, would that have any significant effect on
> > antenna performance?
> >
> > Has not happened but I was wondering as it appears I am about 5 degrees
> off
> > horizontal now.
> >
> > Thanks,
> >
> > Bruce K1MY