Simulating a single-boom 13cm/70cm ao-40 antenna with MMANA
MMANA is a very powerful software (freeware) written by JE3HHT - Makoto Mori.
It bases on NEC-math. As a project to first play with this software I simulated the
effects of adding a 70cm Yagi to a 13 cm helix on the same boom.
If you want to play around yourself, here you get the soft.
It is easy to do first steps with included example-files. I have simulated various
helix versions, just download them and scale 'em to your needs..
2 turn helix
4 turn helix
8 turn helix with reflector and 5el. 70cm Yagi
16 turn helix
28 turn helix with reflector
32 turn helix
MMANA screenshot, after loading one of the above files, the "VIEW"-screen looks like this
MMANA screenshot, calculated gain and lobe config of 16 turn 13cm helix interleaced with 5el. 70cm Yagi
depending on the number of segments calculation takes some time,
for the 28 turn helix with reflector: 1200 segments, 45 sec. on a pentium 1200