Want to build the repeater

[Tetra40]

Hello guys,
I'm actually new to repeaters and electronics, i want to build a 2m portable or base repeater, but i don't know what i need to solder, my friend recently made a repeater using Kenwood TK-250 for RX and Motorola MTS2000 for TX, so i want to build something like he done, but i don't know how to do it. I have Motorola CP040, Motorola GP300, Motorola Maxtrac and Kenwood TK-250, so the question is can i build it using two of mine radios that i mentioned, and it will be better if the Maxtrac will be TX radio, because it's 40w, so what i need to solder and what radio can i use for RX, Thank you!

[Tom in D.C.]

There is a website called Repeater Builder, so look it up and see if it helps you.

A standard mobile radio is not usually built to withstand the rigors of repeater operation such as continuous transmitting for long periods of time with little or no rest between transmissions. Also, you will need a duplexer to split the tx and rx simultaneous signal to a single antenna and avoid crosstalk and interference, unless you use two antennas, which is difficult to make work on VHF because the frequencies are usually only 600 kHz apart.

So, you've got a long path ahead of you to learn what's needed, but if you do it one piece at at time you can probably succeed.

Have you applied for frequency coordination yet for your repeater?

[Tetra40]

Yes i have frequencies.
I was looking at Repeater Builder website, but can't find any info for me, or i just can't read.
I don't know for the beginning i will be using two antenas, and if repeater will be doing its job i will buy duplexer.
So again if you say maxtrac i bad, please help me find better radio, again i have: Motorola Maxtrac, Motorola GP300, Motorola CP040, Motorola GP388 and Kenwood TK-250, also i have Wouxun KG-UVD1P if it's can be used for repeater.

[Tom in D.C.]

Try this site:

http://www.repeater-builder.com/rbtip/

Good candidates for conversion to repeater use are heavy-duty mobile radios such
as Motorola's Mitrek series. The Mitrek can be converted to a complete repeater in
one single transceiver unit. Do a Google search for Motorola Mitrek Repeater conversion.
One site is at http://www.n1uec.org/n1uec/mitrekrepeater.html.

[AEC]

Tom:
From his SC, I thinkhe is either in Europe, or Asia.
Tetra is not used much to date, so I am assuming here of course, so many radios common to us, might not be available to him.

As a note, I would suggest he NEVER use ANY portable as a receiver OR transmitter.
Neither will perform satisfactorily for him, beter to use mobiles and a repeater amplifier after the transmitter(once turned down) to boost the transmit signal without taking out the transmitter's PA.

Always use a duplexer tuned properly for best results/range.

[Tetra40]

Ok thanks, yes i live in Lithuania, Vilnius and we don't have much radios as you have, so we need to buy them from ebay, and wait for about 1 month till they arrive, and i don't have much money to buy the radio's you say, sorry, but thing i know is that i can do it with radio's i have (correct me if this is not true)

[Bill_G]

Welcome Tetra.

Since you are new to electronics, it is best to start simply. Repeaters are not difficult, but they are easily made incorrectly. The recommendation to read the Repeater Builder site is excellent. It has many articles on several models of radios for you to learn from.

You need two mobiles of the same type such as two Maxtracs.
You need the programming software (RSS), the programming cable, and the programming box (RIB).
You need a repeater interface controller (RIC)
You need a duplexer.

You can use any model of mobile radio as long as it has an accessory connector on the back with the functions required for a repeater. Those functions are - transmit audio input, receive audio output, PTT in, receive detect out (COR or CD), and ground.

You can construct your own RIC. They are quite basic. The Repeater Builder site has several designs. But, for a beginning effort, I recommend you purchase one intended for the model of radio you choose.

You cannot build your own duplexer, and while it is possible to operate without a duplexer, I highly recommend you get one, or you will be very disappointed in how well your project works. You will need the aid of a technician or engineer with test equipment to properly align the duplexer for the frequencies of operation. You really cannot skip this part.

I hope this helps you.

[Tetra40]

Thank you very much, while i was reading information about repeaters on repeater builder website i just made one, using Kenwood for RX and Maxtrac for TX, i was having broken repeater box with Kenwood on RX, there was no TX, so after 1 hour of experiments my maxtrac radio transmitted audio that was heard on Kenwood, so i have a repeater, but there is some problems:
1) There no repeater tone for like 1 or 2 seconds after kenwood stops receiving so i don't know if im in coverage or not.
2) When on this repeater was another radio it was transmitting OK, and audio was loud and clear, now when i connected my maxtrac audio of transmission is very quiet, why is that?

And some photos of this repeater i made my self, but actually i just connected a TX radio to repeater that was not working because TX radio was broken
http://imageshack.us/g/1/9939671/

[Will]

2) When on this repeater was another radio it was transmitting OK, and audio was loud and clear, now when i connected my maxtrac audio of transmission is very quiet, why is that?

That would be due to the higher audio level required for the Maxtrac Mic input. About 80 to 120 mV for two thirds deviation.

[Tetra40]

Thanks, but how can i do that? What i need to do to get bigger power?

[Will]

Look here: http://www.repeater-builder.com/motorol ... k-rev2.pdf

This has the drop-out delay or repeater "hold", time out timer, and audio gain to drive the Maxtrac Mic input.

These are used on commercial repeaters with very good results.

[Tetra40]

OK. Thank you very much for your help, it's going to be difficult to make because there are different radio's on RX it's Kenwood TK-250 and on TX there is Motorola Maxtrac, so i need to make special cables, but anyway im gonna make it.

[Will]

OK. Thank you very much for your help, it's going to be difficult to make because there are different radio's on RX it's Kenwood TK-250 and on TX there is Motorola Maxtrac, so i need to make special cables, but anyway im gonna make it.

Just PM me and I can get the wiring for the ID-O-Matic to radio xx. to you.