Andresyncro wrote:Good Day , I need some help
I've got two GM 350 radios ,one a vhf model and the other a UHF model.
I would like to crossband the two radios.
I had a look on the group and found the wiring to crossband the two and connected it up like that, it shows GM300, M120, or M10. I tried doing it that way, But the 2nd radio the UHF radio go into tx immediately.
Is there another way of doing this besides buying a RICK interface. I saw a video on Youtube with two radios connected together with a small board on the aux plug and a interconnecting cable.
Please
Thank You
Andre ZA
There is more to it than just wiring up 2 radios back to back. Not having a controller of some sort in between the radios to act as the traffic control cop is like asking to drive a vehicle down the road with no brakes.
You need to consider important things like tail on the transmissions. This is needed to at least let the users know they were able to at least get into the repeater.
Don't forget that you also need to have a time out timer. This is needed to prevent accidental lock up of the repeater from a transmitter staying keyed on the input.
Controlling the audio level going into each transmitter is very important. You can't just take the speaker output and stuff it into the other transmitter. Each time you change the volume control, the transmit audio on the other radio will change. This needs to be from a fixed audio source. It probably needs to be from a filtered audio source so your not trying to pass through the CTCSS tone that may be used to open up the receiver. If your using different tones on the 2 radio receivers, this could cause problems on the transmit side if your also injecting a different CTCSS tone. Need to think this through carefully.
You didn't say if this back to back radio package was to be able to repeat in both directions or just in one direction. Need to know this before you try to put the electronics together.
If the plan is to use this as an emergency fill in package, what are you going to use for a power source? What are you going to use for antennas on the 2 radios? How are you going to support the antennas? How are you going to weather proof the package?
The location of this radio package really needs to be known. Is it going to be placed at a tower site where there are other radios in the same band as your planning to put these radios? You have to take into consideration that using a radio not designed for a high RF environment could cause you all sorts of receiver problems. Probably would require you to put pass band cavities on both radios.
Not trying to put the brakes on your efforts, but there is a whole bunch of planning that needs to go into putting a repeater package together. Some planning up front will pay off big time in the end.
OK, I have passed along some thoughts for you to consider. Let the group know how you proceed and what you did to put you idea together. Others can learn from your efforts.