[TowerTalk] TowerTalk] Force 12 Delta 240 2 Elem 40M Yagi

Grant Saviers grants2 at pacbell.net
Wed Apr 16 12:38:29 EDT 2014

"Shorty forty" is a term subject to much interpretation.  The biggest 
challenge with the W6NL Moxon is more likely getting it on the tower 
with the Moxon tips.  Even more so with the smallest 2L 40m,  a Moxon 
design from OptiBeam, since the ends of the elements are tied together.

Here are some specs from various 2L 40m designs

antenna        turning R ft    weight #    2:1 bw KHz

XM240            24                55                250
F12 240N        30.4            85                290
M2 40M2L       27                68              150
HG DIS72         25                68                200
W6NL Mox        30.5              80            350  (120MPH scratch 
build version)
OB2-40Mox        20               77               350
OB2-40             26                77                170?
full size 2L          40                200           150?  (3" boom, 
76' guyed reflector, 100mph design)

I didn't include wind survival speeds, but there is a large variation - 
80mph to 120mph.  YMMV.  The full size 2L data is 2/3 of a 3L full size 
40m OWA I own and plan to convert to a "shorty 80m" 2 element tuned with 
Tornado inductors.

I apologize in advance if I've misquoted/misinterpreted any 
manufacturer's specs and for what the reflector does to formatting.

Grant KZ1W

On 4/16/2014 6:03 AM, john at kk9a.com wrote:
> This is a great design, however with the 19 or so foot T sections it is
> not a small antenna.  I would not consider them to be a shorty forty.
> John KK9A

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