At 11:47 AM 2/4/01 -0500, Tom Rauch wrote:
>If you want truly wide-band performance...forget a Uda-yagi
>antenna. Its primary advantage is simplicity, not bandwidth or
>performance.
...
>
>You can get octaves of bandwidth using either method.
>
>For Ham use, a simple yagi or array of yagis is plenty good. I live
>in a rural area with very few buildings or uncontrolled metallic
>objects around my antennas. Even in my very open environment,
>ionospheric scattering and multi-path limits useful antenna null
>depth to perhaps 20 or 30 dB. If you shut the door more than that,
>it does no good. You still hear the backscattered signals from the
>rear.
Sure, but that was precisely my point. No point in optimizing for
super-deep F/R nulls, particularly if the trade-off is gain bandwidth or
SWR bandwidth (or F/R bandwidth for that matter). I'm not talking about
octaves, of course -- just enough to cover an entire ham band with
acceptable performance in all 3 dimensions. The OWA yagi and designs like
W3LPL's 5-element yagi on 4 elements worth of boomlength are good examples
of how that can be achieved without relays or other unreliable mechanical
devices.
73, Pete N4ZR
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