Greg, antennas affect transmit and receive equally, so the user's poor antenna, or the repeater's good one, has no real bearing on alligator/elephant effect.
Achieving balance in a system requires accounting for the noise environment, and the mobile is likely to have much more noise than the repeater location, due to vehicle ignition and electronics nearby. The noise problem will be a bigger factor on 10m than at VHF. 100 watts on the repeater vs. 25 watts in the mobile is a difference of only 6 dB, which is probably very reasonable for compensating the system for mobile noise and preserving balance. 73, Paul, AE4KR ----- Original Message ----- From: ac6vj To: [email protected] Sent: Saturday, January 05, 2008 5:20 PM Subject: [Repeater-Builder] Re: 10 meter split site Hi Steve, I have 2 1/2 mile distance between my receiver and transmitter on my 10 meter repeater, and have no desense on the receiver. One of the important things is that the receiver has a high dynamic range. I am using a Micor receiver because of its ability to reject nearby signals. 100W is kind of high power for a local 10 meter repeater. From your location 40 to 50W is plenty of power, at that elevation and should give you coverage from Redding to Fresno, and the lower power level will help on your receiver defense. Don't forget that your users will probably be using Radio Shack mobile radios that on a good day can barely make 25W, and there antenna is not as good as your repeater antenna. After all, you do not want to end up with an alligator, but with a balance system that matches your users ability. Gregory AC6VJ --- In [email protected], Steve Allred <[EMAIL PROTECTED]> wrote: > > I am in the process of building a 10 meter repeater and was wondering if I could get some help form you guys. > What is the "best" distance separating Tx from Rx on a split site repeater without creating a big disparity between "talk in vs talk out", yet still provide the needed isolation? I have tried to interpolate the DB horizontal isolation charts but with only minor success. I also have modified DB pass cans to cover 29 MHz, so I have some pass protection on the receiver and transmitter. Output will be in the 100 watt range to an lowband DB201. > > Any thoughts? > > Thanks! > Steve / K6SCA > > > --------------------------------- > Never miss a thing. Make Yahoo your homepage. >
