Date: Fri, 2 Jun 2017 09:30:52 -0700
From: Grant Saviers <grants2@xxxxxxxxxxx>
To: w5wz@xxxxxxxx, towertalk@xxxxxxxxxxxxxx
Subject: Re: [TowerTalk] Modify Force 12 C-31XR to create mono-band
OWA ?
<Why? What is the goal?
If you want an Al pile to make 3 monobanders, there are probably cheaper
ways to buy the Al. In any case two more booms are needed.
The "handbook" and other (e.g. G0KSC) mono-bander "free" designs are
good to superb. From my limited experience with interlaced design
modeling my estimate is 1db or unlikely 2db more gain and somewhat
cleaner pattern than a tri-band interlaced design if same net boom
length per band. I think it unlikely you will have successful
mono-banders by just de-interlacing the existing C-31XR elements. Each
resulting monobander will need to be modeled and optimized. I would
suggest investing in an NEC4 package and Dan AC6LA's great AutoEZ optimizer.
What I have learned in my modeling is great respect for successful
interlaced designs like the C-31XR and the JKantenna designs. It's hard
to put everything on one boom and get performance very near to that of
mono-banders.
Grant KZ1W
## He may just want to Re-use the 20-15-10m eles from his C31-XR as a source
of tubing. IMO, if you want tubing, buy it new from DX engineering, since its
cheap.
Then sell the C31-XR as a complete yagi.
## JK antennas indeed does have interlaced arrays that have slightly MORE gain
than their
individual counterparts.
## On a similar note, JK ants has revamped a lot of the legacy F12 yagis,
re-designed on
NEC-4..and also updated mechanically . The 5BA has also been re-designed, with
better performance
than the original, with 2-3 less eles.
## If the OP just wants 3 monobanders, start from scratch, sell the C31XR..and
buy tubing from dxe, and
build your 3 x monoband owa style yagis.
Jim VE7RF
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