RE: [Repeater-Builder] Handheld antenna on a Mobile Radio?

[Eric Lemmon]

I would not expect that setup to work very well.  Most portable antennas are not very good matches to the output stage, and the portable radios are usually designed to handle wide SWR swings without complaining.  The antenna impedance varies a lot as the radio is moved around the body of the user, inside vehicles, and in various angles to a wildly varying ground plane.   When such an antenna is placed right on the back of a mobile radio, it is almost expected that the PA protection circuits will trigger on high SWR and/or reflected power.  A rubber duck or whip antenna is not a very efficient or effective radiator for a base station.   My suggestion is to use a 1/4 wave whip on a magnetic base with 12 feet or so of RG-58 cable, so that the antenna can be "remoted" from the operating position and placed on top of a nearby file cabinet or refrigerator.  This provides a ground plane for the antenna and also puts some distance between it and the operator's head.   73, Eric Lemmon WB6FLY From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, February 26, 2006 6:53 PM To: repeater-builder@yahoogroups.com Subject: [Repeater-Builder] Handheld antenna on a Mobile Radio? Has anyone ever used a handheld whip antenna for their mobile radio used as a base?  I've seen this setup used a few places, and it worked great, but it was on UHF.  A simple 90 degree Mini-UHF to BNC-F, BNC-M on the antenna.  I tried this (on our VHF Radio) and it seems to either shut-down the radio or barely get any signal out.  Is there any secret to this or a certain antenna type that needs to be used?  ie. Base-loaded or Helical Whip. Thanks for any input! YAHOO! GROUPS LINKS  Visit your group "Repeater-Builder" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.