I am new to repeater building. what i have is two m120's and a rick. a cw id controller. What i want to do is to build a repeater for emergency operation, ie: move from mountain to mountain. I do not want to use duplexers. I understand i can use tx and rx antennas instead. What else do i need to complete the system and how do i do it?
thank you,
wayne
BUILDING A REPEATER
Moderator: Queue Moderator
Re: BUILDING A REPEATER
A little research on the subject using Google and www.batlabs.com should yield a wealth of information on the subject.
With regard to not using a duplexer, it can be done, but the configuration can be tricky. What band are you using? The higher in frequency you are, the easier it becomes.
If this is a VHF system, you are going to need a significant amount of vertical antenna separation between transmit and receive. If it is a UHF system, the same applies, but the separation needed is not as great.
Why the opposition to using a duplexer?
With regard to not using a duplexer, it can be done, but the configuration can be tricky. What band are you using? The higher in frequency you are, the easier it becomes.
If this is a VHF system, you are going to need a significant amount of vertical antenna separation between transmit and receive. If it is a UHF system, the same applies, but the separation needed is not as great.
Why the opposition to using a duplexer?
Re: BUILDING A REPEATER
the freq is 2 meters, the opposition to duplexer use is because i want to be able to throw the unit in the car and take it to a site and set it up quickly and at minimal cost. this area is mountainous and verizon cell coverage is sparse to say the least. repeater coverage is quite good except in valleys. since it is intended for emergencies the small size and ease of moving it around is quite important. if there is a duplexer small, robust, and inexpensive i would not be opposed to it. i have looked around batlabs and repeater builder but have not found what i am looking for. i'm not even sure what it is, but i am learning.
i have been informed that the vertical separation required is only a 1/2 wavelength. i believe motorola recommends about 60 feet at 150 mhz.
i have been informed that the vertical separation required is only a 1/2 wavelength. i believe motorola recommends about 60 feet at 150 mhz.
Re: BUILDING A REPEATER
Well there isn't such a thing as a "small, compact" duplexer for 2 meters.
I would keep your transmitter power level to the absolute minimum required to maintain communications as this will also help minimize desensitization of the receiver. A single pass/notch bottle properly tuned would probably do some good as well.
I would keep your transmitter power level to the absolute minimum required to maintain communications as this will also help minimize desensitization of the receiver. A single pass/notch bottle properly tuned would probably do some good as well.
Re: BUILDING A REPEATER
Does anyone know if there is a "how-to" for making a diode matrix to use on the 16-pin port so that I can put together several gm300 radios on various bands so that anything received on one radio keys up the others (without trying to key up itself). Lines to be used on the matrix are COR, PTT, rcv audio, xmt audio. I also have a gtx900 with 16-pin port to add to the mix.