It would be interesting to hear how you would connect TWO 2Mtr. radios (assuming a standard .600khz split and a single antenna connector on each) thru a duplexer(s) to a single feed line and antenna. What type duplexer(s) are you suggesting ? Have you done this before ? Just curious.
Doug N3DAB --- In [email protected], Chris Robinson <kf6...@...> wrote: > > 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) <kb1...@...> 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" <wb6fly@> 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? > > > > > > > > > >
