under the description you give you can put them on top of each other separated by a 1/2 wave or better without any real problems. if you are only going to transmit on one at a time then you wont have any reall issues. You will be able to run up to about 25 W without any problems that I can think of. I run a couple radios here at home and have the antennas relative close and only have problems when i kick up over 25W and then it is just some noise but nothing strong enough to kill the receive on the other rig.
You can still use a duplexer and run two rigs to same antenna without any problems as well. then you would only have the one coax to worry about really. tends to make things cleaner looking on the install too! On Mon, Oct 26, 2009 at 9:48 PM, Jeremy (KB1REQ) <[email protected]> wrote: > > > > The icom runs a max of about 65 watts but almost always less, more like 5 > or 10. The antenna I hope to set up is a mobile 5/8 waxe over a > ground-plane. My purpose is for skywarn activations, as an NCO it would help > to be active one two frequencies nearly simultainously. > Any further help is appriceated. > > > --- In [email protected]<Repeater-Builder%40yahoogroups.com>, > "Eric Lemmon" <wb6...@...> wrote: > > > > Jeremy, > > > > You did not provide enough information to give you a good answer. How far > > apart are the frequencies involved? How powerful is the other radio? > > > > What I can tell you right away is that vertical separation is far, far, > more > > effective than horizontal separation. If both radios are going to be > > frequency-agile, that is, there may not always be a fixed separation in > > frequency, then the simple answer is: Separate the two antennas > vertically > > as much as you can, one over the other, and hope for the best. Use > > double-shielded cable for feedlines on both antennas. > > > > Damage to the receivers is not likely, since most good radios have diode > > protection on the front ends. After all, look at almost any "mobile > command > > post" vehicle, and you'll probably see a dozen antennas on the roof- > usually > > no more than a foot or so apart. Although major desense is almost > > guaranteed when any one of the radios transmits, judicious use of > > preselectors (such as those made by DCI) can minimize it. > > > > -----Original Message----- > > From: [email protected]<Repeater-Builder%40yahoogroups.com> > > [mailto:[email protected]<Repeater-Builder%40yahoogroups.com>] > On Behalf Of Jeremy (KB1REQ) > > Sent: Monday, October 26, 2009 6:24 PM > > To: [email protected]<Repeater-Builder%40yahoogroups.com> > > Subject: [Repeater-Builder] Antenna spacing > > > > > > > > This post does not necessarily relate to repeaters, but some of the same > > calculations can be applied. I am interested in installing another two > meter > > radio in my shack and was wondering what kind of spacing is needed as to > not > > over load either of the radio's receivers. I currently have an icom set > up > > on a j-pole, and I have a 45 watt GM300 that I want to add. What would be > > the best placement of antennas to reduce desense. or otherwise damage the > > receivers? > > > > >
