[Antennas] Antenna software favour to ask

Tue May 29 00:24:35 EDT 2007

As a 5/8wave on the resonant freq, the main lobe will be below 30degs....and you will see ~3db gain over a standard 1/4wave Ground Plane. You will have a secondary lobe at about 60deg but it will be minimum and not have any effect on the main lobe.
At 160MHz, the same vertical whip will show a higher radiation on the secondary lobe as the antenna will be longer than resonant freq requires but it may not be noticable on the air. The antenna will still work but your actual radiated RF may be less if the matching network has higher loss (due to reactance). Are you wanting to xmit on both freq? if so, better to center the antenna resonant freq higher than 148MHz (it will still show low SWR and decent gain in the ham band).
Chris
WB5ITT
-----Original Message-----
>From: k3hx at verizon.net
>Sent: May 28, 2007 6:49 PM
>To: antennas at mailman.qth.net
>Subject: [Antennas] Antenna software favour to ask
>>I'd be grateful if someone would run an antenna 
>>analyzer iteration which would provide a radiation 
>>diagram of an ideal 5/8ths wave vertical cut for 
>>146.52 mHz and another iteration of the same antenna 
>>as operated on 160.89 mHz.
>>73,
>>Tim
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