Help with DIY Icom repeater

[RFI-EMI-GUY]

That's not a duplexer. Thats a power divider.

Who let the smoke out!

 

[buddrousa]

SMOKE SMOKE
SMOKE SMOKE
PUFF PUFF
PUFF PUFF

 

[a417]

Security companies like this belong on Zello.

 

[DeoVindice]

I'm truly in awe of what I just read.

 

[mmckenna]

I see well it seems to be working so would that be fine for now or do you suggest something else?

Well, if you read through the posts above, you'll see people talking about duplexers. You need a duplexer.

Here's the challenge:
You can buy duplexers on Amazon, sure….
You can even pay them to "tune" the duplexer to your licensed frequencies and ship it to you.
-But duplexers are mechanical devices, and getting bounced around in shipping results in them getting knocked out of tune. No one who does this stuff for a living would rely on a duplexer arriving tuned and ready to go. It doesn't work that way, no matter what the guy taking your money tells you. I'm not trying to rip you off here, I'm not asking for money, I'm telling you the truth.
To do this right, and have it work well (as in people will depend on it for critical communications), you would need to pay a competent technician to tune the duplexer once it is installed and ready to go. The test equipment to do that sort of tuning runs in the tens of thousands of dollars. I have one, $20K. This isn't something you buy off Amazon/e-Bay and just plug in.

Several competent people have asked questions about your setup so they can try to help you, but you don't seem to be answering them.

There's some other challenges:
The frequencies used by this repeater need to be properly coordinated with an FCC approved coordinator:

Industrial / Business Licensing

Licensing Individuals or entities desiring to operate on frequencies listed in the Industrial/Business Pool are required to obtain a radio station license for these frequencies. Below is some helpful information to aid you with the licensing process.

www.fcc.gov

Those frequencies need to be properly licensed through the FCC (if you are in the USA)

They will assign a frequency pair to your company for use for the repeater. You can't just take simplex frequencies that are assigned to your company and make them into a repeater. And you don't want to just randomly pick frequencies that you deem to be 'unused' and pop up there.

The repeater is required to identify itself periodically with the FCC assigned call sign.

The repeater needs to have a control method that will take it off line if it malfunctions.

Also, putting two mobile radios back to back and letting them go usually results in a failure. Mobile radios are not designed for repeater use. They are usually designed for short bursts of use and then time to cool down. In repeater operation, they'll see much higher duty cycles than they were designed for. Usually when ham operators make repeaters out of two mobile radios, they turn the power output on the transmitter way down. They also add a cooling fan (or two) to blow air across the heat sinks.

Setting up a repeater isn't something you do by purchasing parts online and putting them together. It requires knowledge, tools, and test equipment.

Your power divider is not a duplexer. It's just connecting the transmitter and the receiver to the same antenna with no filtering. When the transmitter is transmitting, it's overloading the receiver and resulting in the short distances you are seeing. A proper TUNED duplexer will notch out the transmit frequencies from the receiver and the receive frequencies from the transmitter. That lets the receiver -just- hear the traffic coming in from the hand held/mobile radios and not the stronger output of the transmitter.

I can appreciate your desire to experiment on your own and build your own repeater, and there are a lot of people here that would be happy to assist you. But you need to pay attention to what they are saying. What you have set up now is very likely going to destroy the receiving radio in short order.

You can make this work correctly (if the radios are still good) with a proper controller, a proper tuned duplexer, the correct coaxial cable (you can just use whatever you have on hand) and a proper programming.

 

[MTS2000des]

I highly doubt a "get her done teknishun" is gonna care about licensing, frequency coordination, proper tuning of duplexers, R56 grounding, site leases, et al. But it's okay because they bought it all off Amazon/Ebay!