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THE AM BULLETIN BOARD => Technical Forum => Topic started by: WA4WAX on July 09, 2018, 09:28:12 PM



Title: Any EZNEC Savvy People Around?
Post by: WA4WAX on July 09, 2018, 09:28:12 PM
Hello all!

Would someone be kind enough to run this on EZNEC:

Two dipoles, each 28 feet long, and spaced center to center at 0.125 wavelengths on 14.200 MHz.

Assuming equal currents in each, what phase differential give the best front to back on 14.200 MHz, 21.350 MHz, and 28.400 MHz with the spacing mentioned above?

Do not build a phasing line into the model.  Just assign equal currents, and plot F/B versus differential phase.

Thanks!!!


Title: Re: Any EZNEC Savvy People Around?
Post by: W1ITT on July 10, 2018, 05:58:22 AM
http://hamsoft.ca/pages/mmana-gal.php

MMANA-GAL is a free download and a very capable program.  It's also easy to learn, with its onboard tutorial.  With minimal effort, you'll be able to "build"  all sorts of antennas to see what works and what doesn't.
By the way, when you ask a question about phased arrays, it's helpful to include antenna height.  Mutual impedance with the ground can cause perturbations to otherwise good antenna ideas.  MMANA-GAL will allow you to play with the height once you have "built" the array.


Title: Re: Any EZNEC Savvy People Around?
Post by: PA0NVD on July 10, 2018, 05:36:40 PM
I have (SW) build a 20 meter vertical array with two halfwave verticals above each other. The antenna can be used as well as a half wave vertical for 40 meters. Nice low radiation angle for DX
I also used MMANA . Indeed very nice program. You can see the results and the data of the antenna in the ANTENNA section of AMFONE. It was my first project with MMANA and indeed quite easy to start. And I am NO software man.
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands