repeaters towers...

[Aircargo]

can someone explain to me what exactly does these towers do...what do they send or deflect signals....how many are there for a pd dept?

just curious txs all...

 

[N_Jay]

can someone explain to me what exactly does these towers do...what do they send or deflect signals....how many are there for a pd dept?

just curious txs all...

A repeater in its simplest form is a base station that re-transmits (or repeates) whatever it receives.
The receiver is on one frequency and the transmitter is on a second frequency.

The mobile and portable units are set to transmit on th efrequencyu the repeater receives, (called the INPUT frequency).
obile and portabel units receive on the repeaters transmit frequency (called the OUTPUT frequency)

Several repeaters can operate on separate frequncy pairs on teh same tower.

Several repeaters can operate on the same frequency from separate towers (using a variety of different technologies).

A PD could function without a repeater, or may have hundreds.

 

[Voyager]

Several repeaters can operate on separate frequncy pairs on teh same tower.

Several repeaters can operate on the same frequency from separate towers (using a variety of different technologies).

And several repeaters can operate on the same frequencies on the same tower as long as the access tones/codes are different. Actually, they can be the same tones/codes, but that makes a big mess. :?

I know someone who received coordination on the same frequency on the same tower as an existing system. Says something about the coordination, or lack of it, doesn't it?

You must have written that very fast, NJ. :wink:

Joe M.

 

[INDY72]

Very nicely stated guys! For an example.....
X County SO has a tower with repeat function on two freq's-
F-1: 154.9800
F-2: 155.1300
Both these are the output freqs.

The input for F-1 is 158.8500, and for F-2 is 153.9500.

The SO not only dispatches for for its own units but also for Town XX, Town XY, and Town XZ.
The SO's mobiles might be assigned a PL tone of 94.8 Hz, TownXX 107.3 Hz, Town XY 173.8 Hz, and Town XZ 189.9 Hz- Thus allowing them all to utilize the same freq's with no interference theoretically. Also lets say that the State Police also can access this repeater with iether CSQ, or another tone, possibly the same one the SO uses,... thus allowing for interop. This could be st up for just one of the Frequency pairs, with say the second dedicated for SO use only. Or you could really mix it up. But as to the basic explanation that these two fine gents gave,.. thats absolutely correct!

At least we didn't get into the talkaround aspect yet lol.

 

[scanfan03]

Or trunked systems. Like MOT Smartzone or Smartnet. :shock:

 

[Aircargo]

"ok"...thanks all...lol one other question...why is it i can monitor further with conventional nice and clear sometimes too.....but cant really reach trunked freq. at same distance just as clear?

 

[N_Jay]

Several repeaters can operate on separate frequncy pairs on teh same tower.

Several repeaters can operate on the same frequency from separate towers (using a variety of different technologies).

And several repeaters can operate on the same frequencies on the same tower as long as the access tones/codes are different. Actually, they can be the same tones/codes, but that makes a big mess. :?

I know someone who received coordination on the same frequency on the same tower as an existing system. Says something about the coordination, or lack of it, doesn't it?

You must have written that very fast, NJ. :wink:

Joe M.

Other than for back up (Main and Stand-By), can you name one PD that has two repeaters on the same frequnecy at the same site?
And if so, why?

 

[Voyager]

Several repeaters can operate on separate frequncy pairs on teh same tower.

Several repeaters can operate on the same frequency from separate towers (using a variety of different technologies).

And several repeaters can operate on the same frequencies on the same tower as long as the access tones/codes are different. Actually, they can be the same tones/codes, but that makes a big mess. :?

I know someone who received coordination on the same frequency on the same tower as an existing system. Says something about the coordination, or lack of it, doesn't it?

You must have written that very fast, NJ. :wink:

Joe M.

Other than for back up (Main and Stand-By), can you name one PD that has two repeaters on the same frequnecy at the same site?
And if so, why?

I never said it was a PD. Repeaters are used by nearly all radio services, not just PDs. The coordination case was a business system. I've also seen multiple GMRS repeaters at the same site on the same frequency. Why? Because most likely one person didn't want to pay the other rent on the existing repeater, so they put up their own. But, there are many reasons why someone prefers their own repeater to one owned by someone else.

Joe M.

 

[INDY72]

Well being that most Trunking systems are in the 800 MHz range, the higher the freq,.. the shorter the range typically.... also trunking systems are usually designed to only cover a local area,...though some are very wide area coverge, whereas conventional systems usually are (for the most part) wide area radiators.

Example: City X uses a conventional VHF Lo Band repeater on 45.4200 MHz,... at 100 Watts of power on an tower 100 feet in the air... its range in the real world is nearly 60 miles or more depending on terrain,... City Y uses a conventional VHF Hi Band repeater on 155.7900 MHz, at same power and hieght,.... real world range is around 40 miles or more depending on terrain,... City Z has its repeater on UHF Conventional of 453.8750 same hieght and power,... range is nearly 30 miles, and then City A runs an 800 MHz TRS and now the coverage with one tower drops to typically 20 miles give or take.

Of course if you add multiple towers, and otherthings that can effect radio waves,... those ranges can change drastically. And figure in skip, ducting etc..... it can get bizzarre! Thus the usage of PL/DPL on most bands,... and the special designs of trunking systems.

Also remember that a system is only as good as the coverage of its mobiles/portables. You can run a 400 watt repeater all day and have pityful coverage if you don't properly design it with your HT's and mobiles in mind. Hence the usage of mobile extenders, and on some systems, multiple towers.

 

[Pro-95]

why is it i can monitor further with conventional nice and clear sometimes too.....but cant really reach trunked freq. at same distance just as clear?

Read my sig.