Tone Codes used on FRS/GMRS/MURS radios???

[N6KB]

Many handheld portable radios use some sort of tone sequence burst to open up the squelch on the receiver. Is there any standardization on the tone burst systems? Or does each manufacturer use it's own system which is incompatible with others?

Yes I know you can listen to all signals using only noise squelch, and thus communicate on the same RF channel between any brands of radios.

Do any FRS radios have plain CTCSS (subaudible tone squelch)?

 

[nd5y]

I have never heard of them using tone burst, only standard CTCSS and DCS.
Are you confusing the useless noise maker call tone function that some radios have with tone burst?

 

[N6KB]

Perhaps I am confused. I thought those audible tone bursts actually did something. So then the "Private Channel" (or whatever a manufacturer cares to call it) function on these radios is actually plain old subaudible tone squelch (CTCSS, PL, CG or whatever) or digitally coded squelch (DCS, DPL)?

If it is CTCSS, is there a "code number" to CTCSS tone or Motorola PL code cross reference? Do various manufacturers use the same designations for the codes?

 

[johnls7424]

Motorolas " privacy codes" are a form of CTCSS tone codes. Try entering channel 1 on FRS frequency into a modern scanner. Talk on channel 1 and change only the privacy code. You will notice too the tone code as well will change for each privacy code. So, yes there is a tone code format for FRS. As for tone burst I don't think that necessarily applies to generalized FRS radios sold to the general public.

 

[jaspence]

CTCSS tones

There is a standard set of tones that all manufacturers use. Some use the actual frequency (94.8, etc), while others use a numbering or letter system. There are also digital (DCS) tones on many radios, even the cheaper ones.

https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System

 

[SCPD]

Each vendor has its own term for the tone to open audio. PL, ctcss, tong guard. Dcs is the digital tone coding. No it doesn't make a radio digital. Just type of tone coding. There is no set standard on public Joe on murs, frs. It's whatever the users set them at. If you want to monitor everything that may be transmitted your best bet is csq (open squelch no tone). Forget about actual digital comms since it isn't authorized on those radios. So NAC and RAN shouldn't apply here. Two different digital tone coding on two different digital formats. Basically the analog tone code is same across the radios though some do allow non standard tones to be used however if the recieving radio can only do standard tones then it won't open the audio. A motorola analog will talk to a analog kenwood or other brand using dcs or ctcss. The tones as said are what those group of users decide to use and there is no you got to use this or that tone.

https://en.m.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System

DCS - The RadioReference Wiki

 

[SCPD]

Perhaps I am confused. I thought those audible tone bursts actually did something. So then the "Private Channel" (or whatever a manufacturer cares to call it) function on these radios is actually plain old subaudible tone squelch (CTCSS, PL, CG or whatever) or digitally coded squelch (DCS, DPL)?

If it is CTCSS, is there a "code number" to CTCSS tone or Motorola PL code cross reference? Do various manufacturers use the same designations for the codes?

There is no "private channel". It just stops others from keying up over you or ignoring other users on same channel only opening up to you aND your own grour or twp radios. Interference can still be a issue but as for private no. Anyone using csq open squelch or a scanner can hear your conversation who is in range. The term private channel is a sales misguided term.

 

[johnls7424]

There is no "private channel". It just stops others from keying up over you or ignoring other users on same channel only opening up to you aND your own grour or twp radios. Interference can still be a issue but as for private no. Anyone using csq open squelch or a scanner can hear your conversation who is in range. The term private channel is a sales misguided term.

That is correct. There are however cause I believe midland and even Motorola did produce them for a short period of time FRS/GMRS radios that had " scramble" as a feature on them. However once the FCC found out about this they were immediately issued a cease and desist order for the product line. These radios are still in circulation somewhere. I know cause myself back in the day had one when we used to go play paintball. Was great cause other teams wouldn't know what we were saying cause it was a form of analog baseline encryption. These radios are long gone. Today worth about double possibly triple what it was paid for at the time. Of course it's illegal to posses them now, but I'm sure there still out there

 

[nd5y]

Perhaps I am confused. I thought those audible tone bursts actually did something.

If you are referring the sound effects that sound like a phone ringer then no they don't do anything

 

[N6KB]

We all know there is no such thing as a private line or a guarded channel with narrowband FM radios. Yet Motorola has sold radios with CTCSS and called it PL or Private Line since at least the '60s and General Electric had the same system and called it CG, Channel Guard. My question is about standardization of the coded squelch systems used in mass consumer market VHF and UHF NBFM radios. What I am asking is what is it really? And do different brands use the same tones or DCS codes? If I have a Uniden FRS radio on RF channel 1 and "privacy" code 1, will it open the coded squelch on a Midland FRS radio that is set to RF channel 1 and code 1? Is there any cross reference to figure out what each manufacturer is using and how to use two different brands together (other than just using noise squelch and no coded squelch)? I believe most of these radios have only a couple of dozen or fewer "codes." I know the list of standard CTCSS tones is much larger than that, and DCS codes have more options too.

 

[DaveNF2G]

Yes, there are a certain number of standardized CTCSS frequencies and DCS codes. A brief online search will turn up the lists. They might even be in the RR Wiki.

 

[FedFyrGuy]

Midian has one of the better charts out there: http://www.midians.com/pdf/tone-signaling-charts.pdf

 

[WA0CBW]

There may be some exceptions but the tones are standard PL tones and DCS codes. How the manufacturer identifies them may be different. 151.4 PL might be tone 25 from one manufacturer but tone 20 from another. The same with DCS codes.
BB

 

[N6KB]

Yes, I know where to find a list of standard and non-standard CTCSS tones, and even the letter/number names for them that Motorola and others use instead of just naming the tone frequency. The question is which tones are the FRS radios using? The list of CTCSS tones has about 50 tones between 67.0 Hz and 254.1 Hz. Yet the FRS radios typically only offer a dozen or so "privacy codes." The question is which tones are they using? And do different brands use the same tones?

 

[N6KB]

That Midian tone signalling list is very comprehensive and worth printing out and keeping in a file (if you're old fashioned and like to use paper files).

 

[Voyager]

If you are referring the sound effects that sound like a phone ringer then no they don't do anything

Other than get attention of someone who isn't paying any.

 

[WA0CBW]

I looked at several Motorola FRS radios and several others (Midland, Cobra, etc) and they have all of the 38 standard PL codes. I would look at the manual for each radio and see what PL codes they have. What model do you have that only has a dozen?
BB

 

[SCPD]

That is correct. There are however cause I believe midland and even Motorola did produce them for a short period of time FRS/GMRS radios that had " scramble" as a feature on them. However once the FCC found out about this they were immediately issued a cease and desist order for the product line. These radios are still in circulation somewhere. I know cause myself back in the day had one when we used to go play paintball. Was great cause other teams wouldn't know what we were saying cause it was a form of analog baseline encryption. These radios are long gone. Today worth about double possibly triple what it was paid for at the time. Of course it's illegal to posses them now, but I'm sure there still out there

I recall those older models. When adp came about it reminded me of those since the surplus market was flooded with low and mid tier equipment. I haven't seen one in a very long time the older midland model you mentoned.

 

[tj20]

lol I guess the swat team will be knocking down my door soon. I bought a set of the Uniden gmr1048 with scramble, I know its simple inversion, from ebay still in the package cheap.

 

[ecps92]

Yes many are common to each Vendor.
Yes many of unique to a vendor
Yes there is a list,

Google the Manual for each of your radios and generally in the back is a list of which tones go to each number

Yes, I know where to find a list of standard and non-standard CTCSS tones, and even the letter/number names for them that Motorola and others use instead of just naming the tone frequency. The question is which tones are the FRS radios using? The list of CTCSS tones has about 50 tones between 67.0 Hz and 254.1 Hz. Yet the FRS radios typically only offer a dozen or so "privacy codes." The question is which tones are they using? And do different brands use the same tones?