Repeater project

December 2001

My first order of business was to build a rack that will eventually hold both repeaters.

This is how the current repeater looks. It'll look much better rack mounted.

Everything will be powered from this fuse panel. I put a ground strap along one leg for a common grounding point. I installed the current repeater into the rack. It looked much better and had a little less noise due to shorter connections.

Now to start with the new repeater....

The receive radio I am using is an old RELM RSP500 portable. The batteries died along time ago and I had been using it in my garage as a glorified scanner.

The transmit radio will be a Yaesu FT-2600 I bought off Ebay. It is a 60-watt radio.

For the duplexer I'm using a Celwave duplexer I've had forever. I sent it off and had it retuned for the frequencies I'll be using. These are band-reject duplexers and are fairly inexpensive as duplexers go. The caveat is that they're only good for frequency separations greater than 4.5Mhz or so. Mine is closer to 7Mhz so it'll work fine for me.

The repeater controller is a Connect Systems TP163.

The first thing I did was open the RSP500 and find the receive audio and COS connections. This is where it is essential to have the schematics...especially since this radio uses surface mount devices. I then connected these to the TP163. I adjusted the COS input at the repeater controller to work with the receive radio. The receive radio COS is normally ~3.0V and drops to ground when the proper signal is receieved. The COS input on the repeater controller was set at 1.5V. All adjustments can be made at the back of the controller, which is nice.

It's good practice to use shielded cable on all the audio connections to reduce unwanted noise.

The FT-2600 has a rear 9-pin serial port connection which provides connections for PTT and transmit audio. These types of external outputs are becoming more common on amatuer radios, and it makes it simpler for repeater building.

June 2003

As often happens, this project was put on the back burner. I had wanted to monitor the frequencies I'm using to see what PL tones others were using so I wouldn't use them. I also had a couple things to do to the tower. It's now a year and a half later and I'm back on the repeater project.

As I began reconnecting and troubleshooting I had problems getting the repeater to recognize the received signal. For some reason it was not wanting to decode the digital PL tone I was using. It would decode a normal PL tone, so that's what I ended up using. It's probably best...some of the guys have portables that don't have digital PL tones.

After I programmed everything and verified it all functioned as a repeater I mounted the components on it's repeater tray.

As I 'officially' get it ready I'll make the wiring the neater.

Here's a shot of both repeaters in the rack.

Here's a shot of the rear of the rack. I used strapping to ground the power supply and power amp to the ground strap.

Here is a view of the connector on the rear of the FT-2600. It is very convenient.

At the present time the repeater works, but I've not officially connected it yet. I still need to mount the antenna on the tower. I'm also going to move the repeater rack inside the house so that it never gets too hot or cold. This will require re-routing the coax of the present repeater and running new ground wire. I'll take pictures of this as I get it done.

Update 2004 - The repeater is up and running. It works okay for what we use it for...talking amongst ourselves around Fayetteville. I'd estimate its useful range at 5-10 miles. It has a low cost antenna and duplexer so it's kind of a mediocre repeater as repeaters go. The duplexer works but because it's not the greatest I get some receiver desense and interference from the transmit side.

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