Tone remote information

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cbus
Posts: 264
Joined: Sun Apr 21, 2002 2:39 am

Tone remote information

Post by cbus »

Can anyone steer me to the best location/website/document that explains how tone remote setups work and possibly some case studies ?

I understand the concept, but would like to sit back and start reading from the basics then onto the advanced stuff to get a good understanding of the situation.

Radios I use are CDM1550/m120/gm300 radios.

I am more looking into the remote control of radios that are off site.

Thanks
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Bruce1807
Posts: 1203
Joined: Mon Jan 16, 2006 7:18 am

Post by Bruce1807 »

its quite simple.
You send a high level guard tone (usually 2175 hz but not always)
This wakes up the remote site.
Then you send a function tone. This tells the station what to do.
Change channel, keyup, monitor or whatever.
If it is a key up you send a low level guard tone to keep the keyup until your transmission is complete. eyup is usually 1950, Monitor is 2050 and channel changees are 650 to 1850 in 100 hz increments.

---I added a "5" to the obvious typo of "217 hz", for anyone who may have noticed/cared--- Wavetar
Jim202
Posts: 3610
Joined: Sun Sep 09, 2001 4:00 pm

Post by Jim202 »

Bruce must have been hitting the juice when he typed his
message. He missed by a few points.

If you do a search for tone remote control on the web, you should
come up with a couple of web sites. Vega, Zetron and a few
others should have some decent verbage on the subject.

To recant what Bruce tried to say is that when you mash
the PTT, the equipment sends out a high level 2175 Hz tone
at a plus 10 db level. This lasts for 120 to 140 miliseconds.
Then a function tone is sent for 40 miliseconds to determine
what the radio will do. This tone is at 0 db level. Next the
idle tone of 2175 is sent and held for the duration of the
transmission. This tone is at a -20 db level. The voice audio
is sent along with the idle tone at a 0 db level.

The high level tone sent at the begining of the sequence is
sent sort of as a wakeup call the the distant transmitter.
the function tone is then sent to determine what the radio
will do. This tone is normally 1950 Hz for channel 1 TX.
It can be any of 16 tones. They are 100 Hz apart and go
down in frequency from the first one. Like the F2 function
will be 1850 Hz. F3 will be 1750 Hz and so on.

Which function tone is used will be determined by how
the radio is set up or programmed. Many times the F3
tone will be used to put the RX into carrier squelch mode.
There is no cast in stone tone selection, but more is at
the whim of the radio shop that set it up. The major
radio companies have some suggested tone selections
that are used. Looking in the radio manual you will find
the tones they sort of use.

Jim


Bruce1807 wrote:its quite simple.
You send a high level guard tone (usually 217 hz but not always)
This wakes up the remote site.
Then you send a function tone. This tells the station what to do.
Change channel, keyup, monitor or whatever.
If it is a key up you send a low level guard tone to keep the keyup until your transmission is complete. eyup is usually 1950, Monitor is 2050 and channel changees are 650 to 1850 in 100 hz increments.
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Bruce1807
Posts: 1203
Joined: Mon Jan 16, 2006 7:18 am

Post by Bruce1807 »

Jim202 wrote:Bruce must have been hitting the juice when he typed his message. He missed by a few points.
Your absolutly right, I had just satggered in from a major session and now I'm suffering
tkiuntke
Posts: 60
Joined: Sat Jan 22, 2005 6:22 am

Post by tkiuntke »

If a train station is where a train stops, what is a work station?
Jim202
Posts: 3610
Joined: Sun Sep 09, 2001 4:00 pm

Post by Jim202 »

This is good information for a paging tone control. I believe the
original question was for tone control. Normally this is for a
simple tone remote control of a standard two way radio.

Could be wrong though, I have been known to provide the
wrong answers to questions before.

Jim


tkiuntke wrote:Or you could try this:

http://www.braddye.com/purc/purc_tones.html

Toby
cbus
Posts: 264
Joined: Sun Apr 21, 2002 2:39 am

Post by cbus »

thanks for the info so far guys :)

Yes, I'm more interested in tone remote setups of two way radios/linked repeaters.

has anyone got some case studies or similar where tone control is used at various sites and multiple in-building handsets linked to a tone capable radio.

I'm basically trying to get a good grasp of how things work from the basic side, then up to the semi advanced. One thing I hate is learning the more advanced side of how things are setup/done without first understanding the basic side, getting terminology correct and understanding what is the best way to get the job done .

kinda reminds me of a tech i know that is an absolute wizz at servicing/repairing/problem solving radios, but when it goes to programming motorola gear, he is all over the place and I end up having to re-do his radios so everything works how it should. i.e. vote scan, zone/channel setup, mdc etc.
Jim202
Posts: 3610
Joined: Sun Sep 09, 2001 4:00 pm

Post by Jim202 »

OK, here is a main point to never forget when using multiple
tone remotes in the same location or building. When originally
shipped from who ever you obtain the tone remote control
units from, the default to having a termination resistor
installed. When used in multiples, only one unit should have the
termination resistor installed. This is normally on the remote
that is the furthest from the radio or tlephone line source.

If the termination resistors are left in, it will cause too much
loading on the line and effect the audio levels. In many
cases, this will cause flaky operation in keying the remote
transmitter if the loading is too great. It will also cause low
transmit audio on the transmission.

Another big problem with tone remotes is the mic gain.
In most cases, there is way too much mic gain as set from
the vendor. This causes excessive background room
noise to be picked up and broadcast over the radio. As
some people have said over time, this high gain can hear
an ant fart from across the room. Not what I would call a
good sounding radio transmission. It generally sounds
like a hollow or echo type effect.

Jim
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