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Larry W4CSC
 
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Default ICOM M-802 DSC Antenna

On Wed, 12 Nov 2003 18:54:05 -0600, "Keith"
wrote:

Well, this is a powerboat. I have a SS forestay holding the mast up that I
could connect to, but the mast is grounded all over. I guess I need to
figure out another antenna to hook up to the DSC receive. The hamstick
sounds like it might be the ticket.

The forestay will work if the bottom end of it you're going to hook
the receiver to isn't grounded, too. Radio has a long history of
"shunt-fed" loop antennas, which is what that forestay would become if
you hook the radio between the open, bottom end of it and the ground
the radio is already hooked to, putting the DSC antenna jack actually
in series with the loop.....

Take a piece of coax and put a PL-259 connector on one end of it. On
the other end, strip off the shield and leave the center conductor
exposed but not so it can short to the unused shield. Clip it to
something handy on the bottom of the forestay. Now, plug this PL-259
connector into the regular antenna jack on the M802 and tune the
receiver from 2 Mhz to 30 Mhz, just tune around a wide freq range, and
see how well the forestay acts as a receiving antenna. Don't
concentrate on the strong SW broadcast stations. Listen around to the
weaker transmitters on the ham bands from 3.8-4.0, 7.2-7.3,
14.2-14.35, 21.3-21.45 Mhz. The low freqs will work at night, while
21 Mhz will be dead all night but some active in the daytime, so do it
at different times over a day. See how well it does as a receive
antenna. You'll hear if it sucks right away because you won't hear
normal atmospheric noise if it sucks. Might surprise you....(c;

Nothing lost in a little test but time.



Larry W4CSC

"Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!"