One channel, multiple parties with tones

[WRXR374]

How many different parties using different tones can "share" a GMRS channel?

[kidphc]

Wouldn't recommend. With tones you don't get more bandwidth. All the parties will stomp on each other during transmission without knowing.

Once carrier is being used, irregardless of tone the frequency is being used.

Tones just ignore the transmissions and doesn't break squelch unless the tone matches.

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[WRXR374]

2 minutes ago, kidphc said:

Wouldn't recommend. With tones you don't get more bandwidth. All the parties will stomp on each other during transmission without knowing.

Once carrier is being used, irregardless of tone the frequency is being used.

Tones just ignore the transmissions and doesn't break squelch unless the tone matches.

Sent from my SM-S901U using Tapatalk
 

Thanks.  I sorta understand about how it isn't really "private".  I'm just wondering... if I'm talking to someone with one tone, and two other people are talking to each other on another tone, what effect does that have on each of us?  What happens if a third pair starts using a third tone?

[kidphc]

Whom ever has the stronger signal wins. Hence the stomping comment, sorry this is how fm/digital fm work. The other transmissions will be lost. This is irregardless of tones. You put tones in people just wonder why transmissions aren't getting through or seriously broken up at times.

If you are sharing a frequency between parties you will want a business license or amateur radio license and utilize dmr/moto turbo. This was designed to reduce collisions via color codes and time slots.

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[Tip10]

Same effect as two transmitters keying up on the same channel with out tones, or three all keying up at same time when you add in the third.

Tones really do NOTHING on transmit except add tones to the transmit - they tones only allow you to set your receiver to ignore transmissions.


Never engage in a battle of wits with an unarmed person.

[SteveShannon]

11 minutes ago, WRXR374 said:

Thanks.  I sorta understand about how it isn't really "private".  I'm just wondering... if I'm talking to someone with one tone, and two other people are talking to each other on another tone, what effect does that have on each of us?  What happens if a third pair starts using a third tone?

This has nothing to do with privacy. When two FM signals are in proximity and use the same frequency, regardless of any tones, they can interfere with each other.  FM also has what’s called a “capture effect”.  Your radio will lock onto the stronger of the two signals.  Again, “privacy tones” have nothing whatsoever to do with this.

[WRXP381]

As many as there are analog and digital tones.  Now after a few and depending on traffic you will start to run over each other 

[amaff]

What all of them already said. All of my radios have a bank of channels with semi-random tones (but they all match, if that makes sense). The goal is find a quiet channel so you're not stepping on a bunch of other people (and vice versa), and then everyone running the same channel / tone pair can hear each other.

When I'm out with friends we'll usually have a primary and a secondary channel ready to go in case someone's already using the primary we picked, so that everyone knows where to go.

[WRXL702]

DCS & CTCSS (PL /DPL Motorola Term) Coded Squelch Types Are Exactly That. A Coded Squelch That Eliminates Your Radio From Hearing Co-Channel Users On The Same Frequency Or GMRS Channel. There Are Several "Tones" Available.

That Does Not Give An Exclusive Use Of That Shared Frequency, Just Enables Your Radio Not To Receive The Co-Channel (Same Frequency) Transmissions. 

So To Answer Your Question, After Explanation - Several "Parties" Will Sill Be On A "Shared" GMRS Frequency Use.
 

 

[TrikeRadio]

As people have already stated, yes the stronger signal will stomp on other transmissions that are weaker in spite of tones. It can distort or cause distortion on the other tone transmission. and if a user is not using a tone on receive (only transmitting on a tone, they will for sure hear the other party in open if it is stronger than the one they intended to hear. Two groups on the same channel/frequency CAN use it together with different tones but it is never likely to be ideal.

[dosw]

There are some nuances I haven't seen mentioned.

 

One is that the "strongest signal" is the strongest from the perspective of the receiver.

 

Another is that two comparable signals will cause strange intermodulation. You hear that when two kids both key up their cheap FRS radios at the same time in different rooms of their house.A nearby listener will hear odd sounding interference.

 

Last, even if you have squelch tones set on your receiver, you may still hear unwanted transmissions. Sometimes someone will transmit the code necessary to open squelch on your receiver but the stronger (different, unwanted) signal will be what you actually hear.