Where are your antennas going to be placed ?? On a tower , on pole mast, on the roof, other ??? If i were going to mount 2 mobile antennas on a tower or pole i would try to fabricate an aluminum plate groung plane and mount one antenna on the top side and one one the bottom side then jury rig a aluminum support structure to mount it to the tower. Home Depot or lowes is a good source for aluminum angle,tube and sheet, but there are other sources as well. A little injunuity and imagination will get the job down. I'll send a photo of one of the mounts i built for antennas on my roof that i use for digi-peaters. along with some other suggestions. Doug N3DAB
--- In [email protected], "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], "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] > > [mailto:[email protected]] On Behalf Of Jeremy (KB1REQ) > > Sent: Monday, October 26, 2009 6:24 PM > > To: [email protected] > > 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? > > >
