Setting up a UHF Repeater (Help please?)

[rescue31210]

UHG. This is getting to be a pain in my neck.

I'm trying to put together some cash to set up a repeater. But I can't really figure out all the information I need: So far this is what I need, feel free to correct anything that might be incorrect, etc. Any help, comments, and suggestions are greatly appreciated!

I'm setting up a repeater right after I get my GMRS license. The repeater will be on 462.575 MHz (RX) and 467.575 MHz (TX) With a Private Line tone of 114.8 (FRS Radio Channel 16 - 16)

I currently have all my radios (UHF Maxtrac, and two MTS2000's) programmed for everything.

Now just as a confirmation, and here's where I get confused, I'd need the following:

1) A Receive radio (This will be a Maxtrac 2 channel UHF radio)
2) A Transmit radio (This will also be a Maxtrac 2 Channel UHF Radio)
3) An Amplifier for both radios, or two amplifiers. (Cheaper to just buy one, but is it safe?)

- Obviously both radios must be 403-470MHz
- Here's my question, do the radios just get programmed as a regluar radio would?
EX - Both radios get programmed for channel 1 as 462.575 PL114.8 RX, and 467.575 PL114.8 TX Is that correct?

4) I need a 16 PIN to 16 PIN connector for both radios
5) I need a duplexer that I know nothing about. UHHHHGGG!!!

- Does the duplexer get programed for 462.575/467.575 114.8 or does it just get tuned for 462/467MHz?

6) I need a UHF 403-470 GAIN antenna.

(All of this is not including antenna cable, etc. Which is going to be another pain in my arsh.)

Here's another question: I was thinking about mounting all this crap in my closet. Which is on the complete opposite side of my room as my desk. Will those radios just need to sit there and look good and do their business in the closet? I'm also thinking about putting them on my new desk if I have the room.

Does anyone have any of this junk for sale? I'll buy it if it's what I need.

Also, this is all going to be around $450. Is there a cheaper way to go about it? I only have $120 in my piggy bank right now, so I can't do much at this current point in time.

Any help is greatly appreciated, thanks in advance.

 

[Lobstah_Guy]

Bass ackwards

Actually, you want your repeater radio to receive on 467.575 and transmit on 462.575.
Have your duplexers tuned for the exact freq of the repeater.

 

[exkalibur]

Maxtracs as a repeater eh? Bad

www.repeater-builder.com

And on yahoogroups, check out the repeater-builder group. There's plenty of people on there who knows their stuff really well when it comes to repeater building.

 

[rescue31210]

Maxtracs as a repeater eh? Bad

www.repeater-builder.com

And on yahoogroups, check out the repeater-builder group. There's plenty of people on there who knows their stuff really well when it comes to repeater building.

Why would it be bad to use Maxtracs?

Which radios would you suggest? Keep in mind, I'm looking for the cheapest way possible.
Thanks.

 

[rescue161]

You have to program one radio as the receiver (RX on 467.xxx) and one as the transmitter (TX on 462.xxx). You use a repeater controller between the two (I'm using an ICS controller and it works great). You can do it without a controller, but you should so the repeater will ID itself with morse code every 30 minutes. If you use a straight cable (16-pin to 16-pin) you won't have morse code ID or control over the repeater, so it will not be legal.

It's bad to use Maxtracs because they get HOT real fast. If it's for light use, it should be fine, but if you're planning on having a lot of users, I'd stick with a real repeater like a Quantar (MONEY).

I have a GMRS repeater here that is two Maxtracs (with cooling fans of course). I do not use an amplifier at all. I turned the TX radio down to about 15 Watts. I used a DB Products folded dipole (4-bay) at about 50 feet above sea level (25 feet above average terrain) and got very good results. We (wife and I) only used hand helds and routinely got about 7 miles from the repeater (14 mile coverage area). On rare occassions I could go about 12-15 miles and still hit it, but 7 was guaranteed.

As far as cable goes, get Andrews Heliax. 1/2 inch will do if you're not talking LONG distance. I used 30 feet of 1/2 inch Heliax for my setup.

The closet will be fine. Just make sure you have some fans on those heat sinks. You can use a "Local Remote" and put it on your desk. They look like a telephone with no buttons (just a handset that you use to talk through the repeater). I use one of the as well. They can be used as far away as 1000 feet away from the repeater (longer if you use an amp). When using a local remote, you listen to the repeaters RX freq and TX on the repeaters TX freq. You can also shut the repeater off via the remote and still talk to radios in the field through the remote.

As far as the duplexer goes, you could get by with a small mobile style (no more than $150.00).

You could get by with $450.00, but that is pushing it.

 

[rescue31210]

Rescue,

Thanks for all the information. I'll be using it lightly, right not it'll only be use to mess around with, then maybe I'll add on a few more "toys" to it when I get more money. But for now, I'll just use it lightly.

You were talking about morse code ID. How can I get that done?
My antenna will be on my 15' mast which is located on my second floor apartment's terrace. So figure it will be up about 30' - 35' feet off ground level. Not sure how much high off sea level that is around here.

As far as the fans, I can program pick up some of that stuff from Home Depot and install it once I have all the parts for the repeater.

You mention lowering the watts on the maxtracs for use with no Amp. How would I do that? Would this enable me the option of straight wall wart?

So I think I'm getting this whole repeater idea thing.

The TX Maxtrac will be programed for transmit (467.575 114.8) but what would I program in as the RX Freq? Moto's cant be programed for "TX Only" lol. (I don't think ???)

And then the RX Maxtrac will be programmed for Receive (462.575 114.8) RX only?

Hmm, I'm probably wrong. Please correct me. Thanks.

 

[wv8mat]

you can use the maxtracs for a long time, the 911 center i worked at, used them as the radios for the consoles the dispatchers were at, had 12 of them on 24/7 for the past 11yrs and only replace one, and had one other repaired, but they werent heat related, lighting got them. and make sure to use good coax, and connectors, when it rains then you will knowif you have good connections on your coax, lots of statics, not good, coax is usually got something funky with it, good luck, send pics when you get it done,

 

[wv8mat]

you can use the maxtracs for a long time, the 911 center i worked at, used them as the radios for the consoles the dispatchers were at, had 12 of them on 24/7 for the past 11yrs and only replace one, and had one other repaired, but they werent heat related, lighting got them. and make sure to use good coax, and connectors, when it rains then you will knowif you have good connections on your coax, lots of statics, not good, coax is usually got something funky with it, good luck, send pics when you get it done,

 

[rescue161]

You have it backwards. The TX radio is programmed to TX on 462.xxx and the RX radio is programmed to RX on 467.xxx

Wal-Warts are a NO-GO for repeaters. You need a power supply that can supply at least 20 amps. 50 amps would be ideal. If you try to use a wal-wart, the radios will just reset when you try to TX on them. Wal-warts put out milliamps, you need amps, as in at least 20.

As far as what mattgregg110 is saying, Maxtracs will run all day no problem when they are receiving, but when you transmit on them for any length of time, they will get HOT real fast. If you transmit on them for too long, they will start decreasing the output power as well until they don't put out anything.

 

[rescue31210]

As of right now I have a seperate Maxtrac that will transmit on the desired frequencies. I think that should work just fine as a base.

Ok, so the TX Radio will be programmed for 462.575 114.8. The RX Radio will be programmed for 467.575 114.8.

Rescue, didn't you mension before that you lowered the Maxtrac to 15 watts and didn't need an amp?

I'm pretty sure I got it all down now.

Anything else? Thanks.

 

[kf4pep]

You really need a proper controller, not just the el-cheapo interconect off ebay. The controller will give you your morse (or even voice) ID, time out timer, and remote control capabilities. You need the ID to identify you as the licensee who owns and is responsible for the station, the TOT to protect your repeater from being burned up by someone dead keying, and remote control to turn it on and off when you are not right there at it.

The cheapest option going is this one:


http://www.arrowantennas.com/uconrtoller.html


I would highly suggest from your questions you find someone with some experience and either buy a complete setup from them or have them help you a great deal. A whole, whole lot of factors can affect how well your setup works.

Or at least take some more time to learn before you jump right into repeater building...you may save a whole lot of money and frustration.

 

[SCPD]

Another suggestion would be to go on eBay or some other outlet and find yourself a Motorola R-100 or a desktop system like a Uniden ARU-251. I had a Maxtrac repeater once and they're not too difficult to build, but not very robust. I started getting a lot of users and had to upgrade. An R-100 can be had for 200-400 bucks and a duplexer another couple hundred more (bandpass only, flat, mobile type like someone else suggested) bucks.

Best thing you can do is spend the money where it counts...on the antenna/coax system. A good antenna and good coax will make a junk radio sound good, whereas a junk antenna would make a Quantar sound bad. Antennas and coax aren't cheap, but worth it.

Took me about 6 months to save up for my first repeater. Then it just got bigger and bigger.

Repeater building can get expensive. I've even got an ARU-251 I'd let go for the right price 300

All you need to do is add an antenna, and plug it in. Duplexer already inside and its crystalled for .575. Need to make room for the new Vertex!

At any rate, the guys that have given you advice have given you good advice so use it and keep learning. There is also a GMRS repeater Yahoo group.

Maxtracs are okay, but you will find it cheaper in the long run to find a desktop, which is made more for repeating.

 

[N_Jay]

you can use the maxtracs for a long time, the 911 center i worked at, used them as the radios for the consoles the dispatchers were at, had 12 of them on 24/7 for the past 11yrs and only replace one, and had one other repaired, but they werent heat related, lighting got them. and make sure to use good coax, and connectors, when it rains then you will knowif you have good connections on your coax, lots of statics, not good, coax is usually got something funky with it, good luck, send pics when you get it done,

Its not about how long it os "on", it is about how much it transmits.

A busy base is about 1/2 of a typical repeater.
(And before a get bunch of crap, that is a rough aproximation)

 

[ReceiverBeaver]

Rescue,

So you're wanting to do this from an apartment complex and have an overall ant. height of only 35'?

1) Have you asked permission from management to put up such an antenna? If you just do it, when they see it they may well order you to take it down......all that trouble and expense for nothing. Even if they grant you permission, if your transmissions interfere with any other resident's anything and they complain about it.....down goes your system again.

2) 35 feet up? How far are you expecting this system to be able to carry? I hope you're not expecting that to go much further than 10 or 15 miles or so. And the antenna had better reach/see completely above the roofline peak or your radiation pattern will be even more severely reduced. The typical repeater antenna is located up a tall tower or high office building or mountaintop.

good luck

 

[prcguy]

Have you considered a Maxtrac is not FCC type accepted for part 95 repeater use?
prcguy

 

[rescue161]

Have you considered a Maxtrac is not FCC type accepted for part 95 repeater use?
prcguy

Tell that to Motorola who markets a R.I.C.K. to use Maxtracs for repeater use. I don't know why it would be illegal as long as you use a controller to ID the repeater. There are MANY systems that use this exact setup.

 

[N_Jay]

Tell that to Motorola who markets a R.I.C.K. to use Maxtracs for repeater use. I don't know why it would be illegal as long as you use a controller to ID the repeater. There are MANY systems that use this exact setup.

Do they market it for Part 90 or Part 95?

Are they standard Maxtracs or do they need any particular options like high stability osc?

 

[rescue161]

Do they market it for Part 90 or Part 95?

Are they standard Maxtracs or do they need any particular options like high stability osc?

Well, the GM300 repeater is two Maxtrac/Radius radios, a duplexer and a R.I.C.K. all combined in a neat little package that Motorola sells for commercial frequencies. If it was not type accepted, then they would not be able to sell it.

Maxtracs are type accepted for business and GMRS, so there will be no problem. As far as I know, there are no restrictions on the repeater itself, only on the type of radios that are used. As long as you use the accepted radios in your repeater, there should be no problems.

 

[awall]

You have to program one radio as the receiver (RX on 467.xxx) and one as the transmitter (TX on 462.xxx). You use a repeater controller between the two (I'm using an ICS controller and it works great). You can do it without a controller, but you should so the repeater will ID itself with morse code every 30 minutes. If you use a straight cable (16-pin to 16-pin) you won't have morse code ID or control over the repeater, so it will not be legal.

It's bad to use Maxtracs because they get HOT real fast. If it's for light use, it should be fine, but if you're planning on having a lot of users, I'd stick with a real repeater like a Quantar (MONEY).

I have a GMRS repeater here that is two Maxtracs (with cooling fans of course). I do not use an amplifier at all. I turned the TX radio down to about 15 Watts. I used a DB Products folded dipole (4-bay) at about 50 feet above sea level (25 feet above average terrain) and got very good results. We (wife and I) only used hand helds and routinely got about 7 miles from the repeater (14 mile coverage area). On rare occassions I could go about 12-15 miles and still hit it, but 7 was guaranteed.

As far as cable goes, get Andrews Heliax. 1/2 inch will do if you're not talking LONG distance. I used 30 feet of 1/2 inch Heliax for my setup.

The closet will be fine. Just make sure you have some fans on those heat sinks. You can use a "Local Remote" and put it on your desk. They look like a telephone with no buttons (just a handset that you use to talk through the repeater). I use one of the as well. They can be used as far away as 1000 feet away from the repeater (longer if you use an amp). When using a local remote, you listen to the repeaters RX freq and TX on the repeaters TX freq. You can also shut the repeater off via the remote and still talk to radios in the field through the remote.

As far as the duplexer goes, you could get by with a small mobile style (no more than $150.00).

You could get by with $450.00, but that is pushing it.

If you turn the tx power down on a Maxtrac they will run hot quicker than if you run full power. But you would still need to run cooling fans because they will shut down after about 1 1/2 minutes of continueous transmitting.

 

[rescue161]

If you turn the tx power down on a Maxtrac they will run hot quicker than if you run full power. But you would still need to run cooling fans because they will shut down after about 1 1/2 minutes of continueous transmitting.

They will will on;t run hot faster if you turn the power down too far... If you tweak it down just right, you won't have that problem. They still get hot no mayyer what you do.