Peter, I donno. The only 1/4 19.5" antenna I ever used I just drilled into the roof above the dome light and installed an NMO mount and simple whip. For conversion of an existing mount, if it is a 5/8's wave vertical (most mobiles are) then there is a matching network in the base.
The little tiny micro whips are ideal, but most of them now are being made as "dual band" which then destroys their 7 dBi gain above the horizon.
No easy answers here. Bob
-----Original Message----- From: Ng, Peter [mailto:Peter.Ng@bccdc.ca] Sent: Thursday, September 15, 2011 12:47 PM To: 'Bob Bruninga '; AMSAT-BB Subject: RE: [amsat-bb] Re: Good mobile antennas to use
<snip> But this is not what a 19.5" whip does. The 1/4 (3/4) wave 19.5" whip does not have gain on the horizon (so it is rarely used for terrestrial mobile) but its pattern is ideal for satellite work on high passes. It does NOT then have a null in its pattern that causes the "crappy" contacts, and it does have plenty of gain above about 25 degrees.... and it is a smooth pattern.... not like the multi lobes of a standard mobile gain antenna. </snip>
Hi Bob,
This is off topic and didn't want to start something on the list... :), but can I convert my current magmount gain antenna simply by replacing the whip or is the "gain" stuff in the magmount itself? If so, would any thin steel rod do? I'd really like to give this a try!
73's Peter VE7NGP