Last year I prepared a Cushcraft 40-2CD and a HyGain 402BA for Field Day.
Each would not show good sweep results and would not radiate well while the
boom pointed up and even with the reflector end raised up three feet.
40M yagis just need to be up higher to test.
-Charlie N1RR
On Fri, Feb 23, 2018 at 9:26 AM, john@kk9a.com <john@kk9a.com> wrote:
> I have never tried tilting the a beam up. It seems like a lot of trouble,
> especially with a long boom and I would not be confident that it is still
> tuned properly. It is quite easy to pull a beam up the side of a tower
> about a wavelength high and take measurements though 1/2 wl multiples of
> coax and then bring it back down to make any adjustments. I have done this
> completely by myself many times and my antennas have a nearly perfect SWR
> curve when mounted.
>
> John KK9A
>
>
> From: "Ed Sawyer"
> Date: Fri, 23 Feb 2018 05:57:39 -0500
>
> I don't find that the "point the beam skyward" method works that well on
> 40M
> beams for doing the initial SWR test. The typical 40M beam is a loaded
> element and on a boom that is usually 20 - 24 ft long. 24ft high is not
> enough to have the DE up and away from the ground.
>
>
>
> It will tell you its not shorted or open but as to whether its tuned right,
> it needs to be in the air.30 to 40 ft up is usually a minimum and even
> then,
> the SWR low point will shift by another 20 - 50khz by the time its up at 70
> - 100 ft in my experience.
>
>
>
> Ed N1UR
>
>
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