Batboard

Hey all.

I have been into radio as a serious hobby for about 10 years now, but I am new to the whole Infrastructure side of radio so please excuse my ingorance...

I am thinking about putting up a 2m repeater and I do not know what I would need.

Here is what I think I need...
-> Repeater itself (I want a p25 repeater, so it will be a used Quantar)
-> Antenna
-> Cable to said antenna (Hardline? Not sure what to do here)
-> Site to put repeater (tower on a mountain)
-> Those big filter things that look like cans, and are always called "cans". (So I can use 1 antenna for both transmit and recieve I believe?)

I have heard talk about exciters and duplexers and something called an epic board but from what all I can tell, those are all in the repeater (quantar, in this case) itself.

Also, as far as puting the repeater on the mountain - how does that work? Does the tower owner do it? Do I hire someone? No clue here.

ANY insight/help would be most appreciated. This project is a bit far off, need to save the $$$ for the parts first.

Thank you!
-Jake

Hi Jake. Yes, you have a pretty good idea what it takes to make a repeater.

You can start very simply by placing a repeater at your house so you get the hands on time making it work. Working with your local group or club, you can eventually place it a site that offers better coverage. There may or may not be site costs involved, but you will be doing all the work.

-> Repeater itself (I want a p25 repeater, so it will be a used Quantar)
I suggest you start with a basic conventional repeater. Learn how to make it work properly, and then move on to making a digital repeater work. An R1225 or a pair of mobiles and a rick are a good starting point.

-> Antenna
Little question with a big answer. As you come across antennas, ask what others think about the model.

-> Cable to said antenna (Hardline? Not sure what to do here)
Eventually yes. At a busy site, absolutely. At your house, not necessarily. You can use cheaper cable that is easier to handle with good results.

-> Site to put repeater (tower on a mountain)
Sure. Someday. Talk to your group and see if you can get hands on time to help with the maintenance, and learn.

-> Those big filter things that look like cans, and are always called "cans". (So I can use 1 antenna for both transmit and recieve I believe?)
You will definitely need something. A basic duplexer uses a simple reject duplexer that allows using one antenna. They are fine at a quiet site like your home, but don't work well at a busy site. Then you would have to invest in better "cans" or cavities. You may even have to split your transmit and receive to two antennas.

You're on the right track. I think you should start small and work big. Gain experience and ask a lot of questions. We're here and there are lots of guys willing to help answer.

Cool, thank you for your help. Taking a second look at it, you are right with the start small with a rick or R1225.

Just to quickly touch on antennas, I have noticed that a 3db site antenna cost much more over a 3db mobile antenna. Am I safe to assume that is because they (site antennas) are built to withstand harsher environments (rain/wind/sun) and the tolerances are tighter, better components...

As my wife told me last night, "Get your feet wet if you have never done this before".

Yes. Base station antennas vary in price based on the quality of the materials used and construction. By necessity, mobile antennas are light weight and essentially disposable because the vehicles they attach to couldn't carry anything else. You could however use a mobile antenna as a base station antenna. Larsen and Maxrad make pipe and wall mount adapters for mobile antennas, and because of the cost they are used quite often. With some exceptions, expect a much lower life cycle and higher maintenance costs using a mobile antenna as a base station antenna.

Don't forget the lightning protection... A Polyphaser, grounding cable and rod.

If I may, this site seems to help quite a few people: http://www.repeater-builder.com/rbtip/