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CTCSS and DCS for privacy


WSDW477

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I understand on how ctcss basically works, but If I want to use either CTCSS or DCS for privacy (I know its not private) due to busy high traffic area, my radios (Baofeng UV-5G Plus) allow for both Transmit and receive settings. Which do I turn on? or both to quiet down the channels outside my group? I go off roading with a group and GMRS is used heavily at the 3000 acre park.    (Menu Settings 10 = R-CTCSS, 11 = R-DCS, 12 = T-CTCSS, 13 =T-DCS)

I hope I explained what Im trying to do well enough.

 

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Ctcss is analog tone. Dcs is digital tone.  You can’t use both at the same time it’s one or the other.  You can set tx to analog and rx to digital or vise versa.  Like you already said it’s not in any way private.  All it does is keep out other transmissions until you key and open squelch.  Then the strongest transmission will still get in.   With 22 channels I’ve never been any place that was so crowded I couldn’t find an open frequency for simplex. 

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Either I didnt explain well enough or your not understanding the question.   I understand digital and analog and the difference and cant use both simultaneously. It more of a setting question on  when to use the programing Transmit vs receive when it comes to either one of the 2 tones.

Lets use a CTCSS 67.0 mhz for an example.              

Would it require on all radios to set the T-CTCSS only to 67.0 or both the T-CTCSS AND R-CTCSS on each since each radio would be transmit and receive? I understand using CTCSS for repeaters only needs the transmit to trigger the repeater. This is for the use of quieter squelch for the group.

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Ctcss is analog tone. Dcs is digital tone.  You can’t use both at the same time it’s one or the other.  You can set tx to analog and rx to digital or vise versa.  Like you already said it’s not in any way private.  All it does is keep out other transmissions until you key and open squelch.  Then the strongest transmission will still get in.   With 22 channels I’ve never been any place that was so crowded I couldn’t find an open frequency for simplex. 
 

on simplex each radio needs to be programmed to the same tones in and out.    On a repeater you can mix and match tones or type of tones.  As for when and why?   It really doesn’t matter in practical everyday terms.    If you use cross tones on a repeater it may help slow or stop some one from figuring them both out 

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1 hour ago, WRXP381 said:

on simplex each radio needs to be programmed to the same tones in and out.    On a repeater you can mix and match tones or type of tones.  As for when and why?   It really doesn’t matter in practical everyday terms.    If you use cross tones on a repeater it may help slow or stop some one from figuring them both out 

To keep it simple lets stay on the original question only ... lets not even worry about repeaters.  As I stated, I understand digital vs analog, but my question is in regards to ONLY programing a group of radios. I set up T-CTCSS on a radio, and it didnt work. I was trying to determine if I needed to include Transmit & Receive both on same CTCSS code to make it work as a group PCode. Thats all.

So using my example below........

Lets use a CTCSS 67.0 mhz for an example.              

Would it require on all radios to set the T-CTCSS only to 67.0 or both the T-CTCSS AND R-CTCSS on each since each radio would be transmit and receive? I tried T-CTCSS only and it didnt work.

......or would I only need to use R-CTCSS to filter out what that radio receives?

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1 hour ago, WSDW477 said:

To keep it simple lets stay on the original question only ... lets not even worry about repeaters.  As I stated, I understand digital vs analog, but my question is in regards to ONLY programing a group of radios. I set up T-CTCSS on a radio, and it didnt work. I was trying to determine if I needed to include Transmit & Receive both on same CTCSS code to make it work as a group PCode. Thats all.

So using my example below........

Lets use a CTCSS 67.0 mhz for an example.              

Would it require on all radios to set the T-CTCSS only to 67.0 or both the T-CTCSS AND R-CTCSS on each since each radio would be transmit and receive? I tried T-CTCSS only and it didnt work.

......or would I only need to use R-CTCSS to filter out what that radio receives?

R-CTCSS is used to filter out what the radio receives, but on most radios you also need to set the “TONE MODE” to T-SQL, meaning stay squelched until the tone that matches R-CTCSS is received. So, of course any radios that you want to hear must transmit with a T-CTCSS to match.

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3 hours ago, WRXP381 said:

on simplex each radio needs to be programmed to the same tones in and out.

Not sure I understand exactly what you mean here so forgive me if I misunderstood. You can use slit tones on simplex. Not sure what the benefit is other than possibly making it harder for someone to interrupt both parties at the same time.

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21 hours ago, WSDW477 said:

I understand on how ctcss basically works, but If I want to use either CTCSS or DCS for privacy (I know its not private) due to busy high traffic area, my radios (Baofeng UV-5G Plus) allow for both Transmit and receive settings. Which do I turn on? or both to quiet down the channels outside my group? I go off roading with a group and GMRS is used heavily at the 3000 acre park.    (Menu Settings 10 = R-CTCSS, 11 = R-DCS, 12 = T-CTCSS, 13 =T-DCS)

I hope I explained what Im trying to do well enough.

 

You are probably using simplex. If you both are using tones, you should both set Tx and Rx, same tone. Think of Rx tone as filtering out any transmission that doesn't have that tone. Think of TX as providing a tone that the recipient can listen for as he filters out everything that doesn't have the tone.

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@WSDW477

Let’s get back to basics.

If radio A transmits with a tone of 67.0 Hertz (not MHz!) radio A will have T-CTCSS set to 67.0 Hz.

Radio B will only reproduce transmissions from radio A if all of the following conditions are met:

  1.  It’s on the correct channel,
  2. It’s in range (but not too close because of desensitization, which is when a receiving radio is swamped by the transmission and becomes deaf.), AND
  3. Either It is set to break squelch when a matching CTCSS tone 67.0 is continuously embedded in the transmitted audio (Tone Mode = TSQL and R-CTCSS = 67.0 Hz)
  4. OR it is set to disregard transmitted CTCSS tones (Tone Mode = TONE, doesn’t matter how the R-CTCSS is set), in which case the radio will break squelch (audibly reproduce) for everything it receives on the channel.

If you want fewer interruptions (which is one definition of privacy) from other people on the same GMRS channel, you must set the receive tone (R-CTCSS) to match the transmit tone (T-CTCSS) (condition 3 above) of the radio or radios you want to hear and you must set Tone Mode to TSQL. But keep in mind that’s only one aspect of privacy.  Others can still hear you and there’s nothing you can do to prevent it.

 

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 I will give an example using our GMRS repeater. We use repeater channel 17. The makes the repeater output frequency the same as the simple channel 17 which is 462.600 MHz. We have tones set on the repeater for both TX and RX so it is in T-SQL mode. Some guys only run their radios in Tone mode with just their TX tones set while others have T-SQL set for both TX and RX.

The people that only have tone set can hear any and all traffic on the simplex channel 17 while those of us with T-SQL set do not hear anything other than traffic coming through the repeater.

Anyone can hear the repeater transmit by listening on simplex channel 17 or repeater channel 17 if they do not have any RX tones set at all.

In fact that is how a few people have found the repeater while traveling through the area. Now they will have to set TX tones to talk to others through the repeater.

As you can see tones act as a filter to keep you from hearing all transmissions on that channel. Tones work the exact same way on simplex too. The term 'privacy tones" is an oxymoron, there is nothing private about it.

Channel 17 (simplex) is pretty popular in my area and sees lots of traffic. If we did not have our repeater and radios set for T-SQL, then we would hear constant traffic no matter if it was on simplex or going through the repeater.

We had one guy complaining about hearing kids on the air constantly. He did not have his RX tones set. once he set his radios to T-SQL, he no longer heard the kids or any other traffic without tones. 

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There is no privacy in "privacy codes". 

So look at it this way, back in the day 4 parties (homes) could share a phone line. You all had a different number, that when it was dialed would make just your phone ring and not the other 3. How? The ringer had a different voltage requirement. If you picked up the phone while the other party was on it, you could hear them. But yours only rang if it was your number and your voltage being sent (correct code in radio). 

So, when you use 67.0Hz or 127.3Hz or say 423 in digital, it makes your radios (your group, your party) private in that only you hear each other and not others, but if someone picks up the line.....meaning opens their squelch or runs carrier squelch....on the same frequency, they will hear you. So it's not "private" it's just keeping you from hearing people other than your group. But, just like the party line phone, only 1 party can practically use the line, frequency, at once. Unless of course you are far enough apart, you can won't hear each other on the radio anyway. 

I think in CCR terms, T-Squelch is transmit only, and Squelch is both ways (what you want). 

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Maybe Motorola should have thought of a better name for CTCSS/DCS instead of Private Line/ Digital Private Line so the term would not be misconstrued as being Private. I think General Electric (GE) had a better idea in using Channel Guard (CG) for naming their CTCSS/Private as a name that can't be misconstrued as being private.

I don't recall what name RCA used for CTCSS/DCS.

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On 8/18/2024 at 11:39 AM, WSDW477 said:

I understand on how ctcss basically works, but If I want to use either CTCSS or DCS for privacy (I know its not private) due to busy high traffic area, my radios (Baofeng UV-5G Plus) allow for both Transmit and receive settings. Which do I turn on? or both to quiet down the channels outside my group? I go off roading with a group and GMRS is used heavily at the 3000 acre park.    (Menu Settings 10 = R-CTCSS, 11 = R-DCS, 12 = T-CTCSS, 13 =T-DCS)

I hope I explained what Im trying to do well enough.

 

You would need to set the R-CTCSS and the T-CTCSS to the tone your group is using.  Let's say they are using 173.8, for instance.  This applies to any of the analog tones.  Be sure to "Confirm" by hitting the "Menu" button after the tone is selected on each Menu choice (R-CTCSS and T-CTCSS).

If you select a digital tone, then you would put whatever tone your group is using in "R-DCS" and in "T-DCS".  For instance, if your group is using "D311N", you would put that tone in both "R-DCS" and "T-DCS".  As with analog, be sure to "Confirm" or set the tone in memory by hitting the "Menu" button after selecting the tone for each Menu item.

Hope this helps.

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On 8/18/2024 at 10:39 AM, WSDW477 said:

(Menu Settings 10 = R-CTCSS, 11 = R-DCS, 12 = T-CTCSS, 13 =T-DCS)

R-CTCSS - Receive - Continuous Tone-Coded Squelch System

R-DCS - Receive - Digital Coded Squelch

And the T is the transmit tone codes. One for receive, one for transmit.

Like most of what everyone else said in here, it's just to silence the other people sharing that frequency.

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On 8/18/2024 at 7:05 PM, WRUU653 said:

 

For a group, yes. Set both RX and TX on all radios to the same tone, code, PL.

Thank you.  I thought both Transmit and receive both had to be set for a simplex "privacy" channel but wasnt sure. As I stated in my original post, I know its not private. When you have 100- 300 people in multiple groups off-roading at 1 park, and each group wants to talk among themselves, it gets crazy on GMRS. I just want to block out noise from outside.

REASON I ASKED, is my radio has an actual copy channel feature that according to Baofeng claims will find the channel AND the CTCSS or DCS code being used. My radio showed NONE instead. I wanted to figure out if its due to transmit not set up right, or the scanning radio doesn't do what they claim it does. 

 

****AND as I stated in my original post, YES I KNOW ITS NOT PRIVATE. I just dont want our group to hear all the mess around us, I dont care if they listen to us.

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11 minutes ago, WSDW477 said:

my radio has an actual copy channel feature that according to Baofeng claims will find the channel AND the CTCSS or DCS code being used

Just in case you don’t know, someone needs to be transmitting for you to pick up tones being used to be able to decode them. 

 

 

 

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