Stacks and SWR
Wed, 12 Feb 1997 09:14:04 -0600
L. B. Cebik wrote:
> Some beam stackers have experienced a rise in SWR if the beams are pointed in
> opposite directions. Others have not. The degree of SWR rise was not
> To shed some light on this question, I ran a pair of identical beams through
> NEC-4. The individual beams, cut to be resonant at 14.175 MHz had the
> following free space properties:
> TO angle Gain (dBi) F-B ratio (dB) Beamwidth Feed Z
> (degrees) (degrees) (R+/jX)
> --- 8.1 26.6 62 25.5 - 0.1
Good stuff, it seems to verify what I see with my three high stack of
4/4/4 on 10-20m and my 2/2 on 40m.
BUT....Where in heavens name do y0ou get a 20m beam with 26.6 dbi gain
and 62 db F/B? Not very real world. I think you probably shrunk a UHF
antenna. At best a long beam like that would have worse case mutual
coupling vs our small .5 to .75 WaveLength booms. HI. So its still a
Maybe I'm interpreting your data wrong?
Thanks for sharing this. My NEC 2 stuff also verifies these trends of
numbers on the smaller beams I use.
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