John Smith wrote:
A half-wave fed with a gamma would need no groundplane... you could build
one better than any you could purchase...

Warmest regards,
John

"Ed" wrote in message
. 92.175...

I haven't fired up EZNEC yet, but I was wondering how a standard 3dBi
marine whip would perform on the 2m ham bands. Since the marine
frequencies are 156.050-157.425 MHz, what could I expect at 144-148

MHz?

If it won't cut it, then does anyone have any recommendations for a
dual-band antenna (commercial or home-built)?

Jon


Jon,

I would expect the marine antenna to perform poorly, due to high SWR.
However, I am not sure of your second question. Are you looking for a
2M/440 antenna for a boat, or for automobile mount? A number of vendors
(Larson, Antenex, Comet?, etc.) sell dual band mobile antennas for those
two ham bands. For a boat, I don't know of any dualband stuff, but those
same vendors sell a base loaded half wave antenna for single ham bands
that doesn't require any ground plane. Good Luck.


Ed K7AAT




John/Ed,

It's for a sailboat (all this has been hashed over in
rec.boats.electronics - I mistakenly cross-posted to rec.radio.antenna,
rather than rec.radio.amateur.antenna, so you guys missed the thread
there). The general consensus is it would be easier to use two antennas,
but I'd have to enlarge the holes in the compression post under the mast
and the mast itself in order to run another cable. If I could find a
pair of diplexers, then at least both radio/antenna combos could share
the same feedline up the mast...

Anyone know of a 2m/70cm diplexer with tight enough filter slope to put
the marine band on the same side as the 70cm, or one specific to 2m/marine?

Jon KB1HTW