I agree that simplex freq's. on each radio would work, in which a simple notch type duplexer or filter cavity would probably surfice. But i got the impression that the original poster was referring to duplex mode on the radios which complicates things a bit with the hardware. I don't see any problem with using 2 feedline and 2 antennas stacked or side by side with a little separation between the m as long as he isn't talking on both radios simultaneously.
Doug N3DAB --- In [email protected], "Chris Curtis" <demo...@...> wrote: > > Probably referring to using a duplexer (certainly NOT a diplexer) to connect > 2 simplex frequency'd 2m transceivers to a single antenna. > ? > > Commonly done > > Chris > Kb0wlf > > > > -----Original Message----- > > From: [email protected] [mailto:Repeater- > > [email protected]] On Behalf Of n3dab > > Sent: Tuesday, October 27, 2009 12:09 PM > > To: [email protected] > > Subject: [Repeater-Builder] Re: Antenna spacing > > > > 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 <kf6nfw@> > > 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) <kb1req@> 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? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 8.5.423 / Virus Database: 270.14.32/2460 - Release Date: > > 10/27/09 07:38:00 >
