[TowerTalk] JK 402 versus CC XM-240

john at kk9a.com john at kk9a.com
Wed Feb 27 08:45:54 EST 2019


Nice summary Jeff.  Gainwise there is no difference between the Moxon 
and the coil loaded 2el.  As I stated below, it is hard to get a lot of 
gain on 40m with a single antenna. Even if you compare the JK404G 
monster 4el full sized element OWA beam against the small loaded JK402 
there is only 2dB difference. There are easier ways to obtain 2dB, At my 
station I stacked two 2el ObtiBeam OB2-40 coil loaded beams and it works 
incredibly well, plus they get along with all of the other antennas on 
the tower.

John KK9A




from: Jeff Blaine AC0C
date: Tue Feb 26 20:48:38 EST 2019

Picking the "best" 40m beam is very hard on 40m and requires a
compromise unless you have a big tower, a big rotor, moderate wind/ice
exposure, height limitations and CW/SSB only vs. wideband CW+SSB.   Oh,
and a serious budget of course.  That's why there are so many different
designs in the market.

A bit of the decision process for both the beam type selection and
suppler may be found here for those interested:

https://ac0c.com/main/page_acc_towersantennas_40m_stack.html

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 26-Feb-19 10:57 AM, john at kk9a.com wrote:
> Momobeam makes a T element 40m beam also, I used one last year 
> operating as
> PJ4R.  I have modeled a lot of 40m beams and it is hard to get a lot of 
> gain
> with a single antenna. The Moxon is a nice design but it does not defy
> physics.
> 
> John KK9A


More information about the TowerTalk mailing list