The 4L 20M on a 53' boom appears on p 8-18 of Lawson's book. There is
another, perhaps less well known, of his designs referred to as a
PV-4 described by Carl Hueter, KM1H and by Bill Meyers, K1GQ in the
May 1986 edition of Radiosporting. (Bill Meyer's article originally
appeared in Scuttlebutt in May 1982.)
On a 0.57 wavelengths boom, this equates to 4L on a 40 foot boom on
20m. Having built one of these antennas I can say that it looks very
strange from some angles due to the spacing of elements on the boom.
Not having a PC at that time, I had to recalculate the element
lengths, with my taper schedule, by hand. While I balanced it for
weight, I failed to balance it 'dynamically' and the widely varying
element spacing played heck with rotators. Young(er) and stupid perhaps.....
Chris G3VBL
At 03:10 09/08/2017, you wrote:
Check out the W2PV yagi book or the W2PV Yagi design series in the
old Ham Radio magazine. Both of which documented a 4L 20M yagi on a
51' boom with big gain and good pattern. It WAS somewhat narrow
banded but one or two extra elements can be added for more bandwidth
if desired.
My buddy W5XZ had a pair of these 4Ls stacked which worked very well
at his former QTH in LA.
Dave, K8CC
Sent from my iPhone
> On Aug 8, 2017, at 8:10 AM, "john@kk9a.com" <john@kk9a.com> wrote:
>
> Gain is a function of boom length however you need enough parasitic
> elements for the Yagi to work. The MonstIR DB42 has a boom length of 42.5
> feet with four loop elements and two straight elements. This is the only
> MonstIR that I see on the SteppIR site so I am guessing that this is the
> antenna you are referring to. Are only the loop elements motorized? 4
> elements on a 42.5 foot boom seem to be pretty big spacing for 20m and
> higher. For example my homebrew 4el 20m OWA beam is pretty wide spaced
> and it only has a 32 foot boom.
>
> John KK9A
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