Tone versus T Sql

[pantherpaw9]

In program softwares like CHIRP and others, there are 4 or 5 different choices for the Tone Mode column.  2 of them are called "Tone" and "T Sql" which I assume stands for "Tone Squelch".  What is the difference and how do you know when to use each one.  I think the other choices are for digital radios or something like that which I'm assuming I don't need so I'm basically concerned with the aforementioned 2 items for tone.  Can anyone educate me on this?

[berkinet]

... I tend to understand diagrametric explanations better than scriptural. So, If you want to look that up in your little dictionary there, it means I like a book with lots of pictures...

 

 

How about video?  I found this on YouTube: https://youtu.be/DAQYfpETDdM

[WRAF213]

Tone means a tone will be transmitted, but the receiver will not check for an incoming tone and will unmute on any signal. TSql means a tone will be transmitted, and the receiver must receive the tone to unmute. There's also split-tone ooeration, which is TSql but the transmit and receive tones are different; I forget off the top of my head how that looks in CHIRP.

[pantherpaw9]

Tone means a tone will be transmitted, but the receiver will not check for an incoming tone and will unmute on any signal. TSql means a tone will be transmitted, and the receiver must receive the tone to unmute. There's also split-tone ooeration, which is TSql but the transmit and receive tones are different; I forget off the top of my head how that looks in CHIRP.

 

So If I want to communicate through the repeater for a particular frequency and also receive signals from anyone locally with Simplex on that same frequency, then I would want to select "Tone".  Alternately, if I wanted to only communicate over the repeater and filter out all other local simplex traffic, I would use "T Sql"  If that is correct, then I think I am very close to grasping this concept.  I hope I got that right, but correct me if I'm wrong.

[WRAF213]

If there's two repeaters with the same tone, using TSql will prevent the other repeater from unmuting your receiver. Simplex activity is probably on a different tone (like CSQ or 67.0) and wouldn't unmute your receiver. If the simplex signal happens to have the same tone as the repeater's output, both will unmute. Not all repeaters transmit an output tone, so some require Tone mode.

[berkinet]

The squelch options (Available by clicking in the Tone Mode column) are:

(None)

Tone

TSQL

DTCS

DTCS-R

TSQL-R

Cross

 

The option to use different tones for transmit and receive is Cross.  If you select that, the Tone and ToneSql (as discussed above) columns will become populated and you can then set each one as you wish.

 

 

 

[pantherpaw9]

If there's two repeaters with the same tone, using TSql will prevent the other repeater from unmuting your receiver. Simplex activity is probably on a different tone (like CSQ or 67.0) and wouldn't unmute your receiver. If the simplex signal happens to have the same tone as the repeater's output, both will unmute. Not all repeaters transmit an output tone, so some require Tone mode.

Does “unmute” mean the same thing as “open up the squelch”. And if so I’m assuming both of these terms mean: “I can hear the other person speaking from the speaker of my radio”. Yes...I’m that dumb. Haha. I know that sounds like basic knowledge to most radio folk but all the radio jargon in these explanations leaves me confused. The good news is my radio is working so this is all about me wanting to truly understand how these radios and systems work.

[berkinet]

Does “unmute” mean the same thing as “open up the squelch”. And if so I’m assuming both of these terms mean: “I can hear the other person speaking from the speaker of my radio”. ...

According to the Cambridge dictionary, squelch means:

to stop something quickly and completely:

One professor claimed that the university tried to squelch his criticisms.

 

So, yes, you are correct!

[pantherpaw9]

According to the Cambridge dictionary, squelch means:

to stop something quickly and completely:

One professor claimed that the university tried to squelch his criticisms.

 

So, yes, you are correct!

So if the squelch is “stopping something quickly and completely” (in this case the something is the signal) the tones act to “un-stop” “open-up” and “un-mute” the signal and pass it through to the speaker and into my ear. I see now why the terminology was used in the previous posts, and I sincerely thank you for the explanation of the word meaning; however, I’m still confused as to what scenario would need a “tone” and what scenario would need a “T Sql”. I’m going to have to sketch this out on some paper and study this a bit more. I tend to understand diagrametric explanations better than scriptural. So, If you want to look that up in your little dictionary there, it means I like a book with lots of pictures...Lol

[berkinet]

So if the squelch is “stopping something quickly and completely” (in this case the something is the signal) the tones act to “un-stop” “open-up” and “un-mute” the signal and pass it through to the speaker and into my ear. ... ... however, I’m still confused as to what scenario would need a “tone” and what scenario would need a “T Sql”. I’m going to have to sketch this out on some paper and study this a bit more. ...

I think you’ve got it... just be clear that the “signal” that is allowed to pass through is the audio output from your radio. The radio signal is being received regardless of whether the audio output is on or not.

 

In chirp’s terms, “tone” is what you send so that others, including repeaters, can know to listen to you. TSql is the setting your radio will use to know when to unsquelch the speaker. Sorry, no pictures tonight... I”m on a tiny keyboard.

[pantherpaw9]

I think you’ve got it... just be clear that the “signal” that is allowed to pass through is the audio output from your radio. The radio signal is being received regardless of whether the audio output is on or not.

 

In chirp’s terms, “tone” is what you send so that others, including repeaters, can know to listen to you. TSql is the setting your radio will use to know when to unsquelch the speaker. Sorry, no pictures tonight... I”m on a tiny keyboard.

Haha, that’s ok, I always try to throw a little humor in these threads for my own entertainment. I’m extremely grateful for everyone’s patience with my questions. I am not where I want to be in my understanding of this topic but thanks to you folks I am getting very close. I’ll keep studying on this.

[Hans]

however, I’m still confused as to what scenario would need a “tone” and what scenario would need a “T Sql”.

The tone is the "squelch code" your radio is sending out. T Sql is "squelch code" your radio is listening for. If your radio doesn't send out the correct "squelch code", the receiving radio will not play the audio through the speaker.

 

Simplex, radio to radio, the transmitting radio would send out a tone while the PTT button is pressed and this would tell the T Sql receiving radio to open the speaker. This is useful in an environment with some considerable radio noise on the frequency where constantly adjusting the squelch knob would be a real pain.

 

In the case of two repeaters near enough to each other to interfere, a different tone sent out by the respective repeaters means that the user can select which repeater will open their speaker. We have two repeaters here, in two different cities, but they are close enough to be heard between the towers. When we want to use the northern repeater, we use T Sql set to the tone that the northern repeater is putting out. Likewise if we want to use the southern repeater.

[pantherpaw9]

When we want to use the northern repeater, we use T Sql set to the tone that the northern repeater is putting out. Likewise if we want to use the southern repeater.

So if two repeaters are close to each other and use the same frequency, you could program each repeater into two separate channel numbers and each channel would be programmed with the different corresponding tones, subsequently allowing the operator to pick which repeater they want to use simply by changing channels?

[Hans]

So if two repeaters are close to each other and use the same frequency, you could program each repeater into two separate channel numbers and each channel would be programmed with the different corresponding tones, subsequently allowing the operator to pick which repeater they want to use simply by changing channels?

Yep. There can be some interference from the stronger repeater so it's not 100% perfect.

 

If the repeaters are too close, however, the interference might be just too much for it to work well or at all. In our situation, the two repeaters are far enough away so that one is always a weaker signal than the other. Think of the two repeaters with big circles around them; one for each. Those circles overlap at some point. Any user in the overlap can use tone to open the desired repeater and T Sql to theoretically hear the repeater they want. However, if both repeaters are transmitting at the same time and their strengths, relative to the user are the same, the interference can cancel out the usable signal. (Think Venn Diagram for the circles. http://en.wikipedia.org/wiki/Venn_diagram )

 

Also, this might help for tones in general: http://www.miklor.com/COM/UV_CTCSS.php

[pantherpaw9]

Yep. There can be some interference from the stronger repeater so it's not 100% perfect.

 

If the repeaters are too close, however, the interference might be just too much for it to work well or at all. In our situation, the two repeaters are far enough away so that one is always a weaker signal than the other. Think of the two repeaters with big circles around them; one for each. Those circles overlap at some point. Any user in the overlap can use tone to open the desired repeater and T Sql to theoretically hear the repeater they want. However, if both repeaters are transmitting at the same time and their strengths, relative to the user are the same, the interference can cancel out the usable signal. (Think Venn Diagram for the circles. http://en.wikipedia.org/wiki/Venn_diagram )

 

Also, this might help for tones in general: http://www.miklor.com/COM/UV_CTCSS.php

Thanks Hans. When I show up to my second HAM club meeting, I am going to blow their mind with all my radio knowledge! Hahaha

[Hans]

I would've given you a like for that but the board told me I reached my quota! lol

 

Remember that my radio knowledge level is quite low compared to many of the fine operators on this board. If I put something out there and they correct it; they have it right and I got it wrong. I learn a lot from each of them here.

[RCM]

Just to state the same thing a slightly different way, in case it helps your understanding: Tone squelch is a filter that is applied to the receive side of a radio or repeater. If it's turned on (as it is with most repeaters), the receiver or repeater will ignore anything that doesn't transmit the proper tone. So you have to program the proper tone in your transmitter, or you won't be able to get into the repeater. Likewise if you are trying to call another station that has a tone squelch programmed.

To recap: to transmit to any station or repeater that has a tone squelch programmed, you must have the same tone programmed into your transmitter.

 

Tone squelch is optional. Even if you have to have a tone programmed to talk to a station or repeater, you don't have to program a tone squelch at all. You will just hear any and all signals on the frequency, whether they are transmitting a tone or not.

If you do decide to program a tone squelch, it must be the same one the repeater or other station is transmitting. Otherwise you won't hear them.

 

Personally I leave the tone squelch off most of the time, so I can hear any activity on the channel regardless of tone.

[pantherpaw9]

Just to state the same thing a slightly different way, in case it helps your understanding: Tone squelch is a filter that is applied to the receive side of a radio or repeater. If it's turned on (as it is with most repeaters), the receiver or repeater will ignore anything that doesn't transmit the proper tone. So you have to program the proper tone in your transmitter, or you won't be able to get into the repeater. Likewise if you are trying to call another station that has a tone squelch programmed.

To recap: to transmit to any station or repeater that has a tone squelch programmed, you must have the same tone programmed into your transmitter.

 

Tone squelch is optional. Even if you have to have a tone programmed to talk to a station or repeater, you don't have to program a tone squelch at all. You will just hear any and all signals on the frequency, whether they are transmitting a tone or not.

If you do decide to program a tone squelch, it must be the same one the repeater or other station is transmitting. Otherwise you won't hear them.

 

Personally I leave the tone squelch off most of the time, so I can hear any activity on the channel regardless of tone.

 

That was a great explanation, and I think it just took hearing the explanation presented in a variety of ways, but I definitely understand this much better now.  This explains why my radio is able to communicate with the repeater without any T Sql settings programmed.  I only have "Tone" selected in my program.  So, if I want to filter any and all other traffic on that frequency, (and only hear signals going through the repeater), then I would have to change my "Tone Mode" from "Tone" to "T Sql".  I can read back in the thread and see now that this was explained already several times but it just wasn't sinking into my thick scull.  haha

[pantherpaw9]

How about video?  I found this on YouTube: https://youtu.be/DAQYfpETDdM

 

Perfect.  I'm going to You Tube on my lunch break.  Thanks

[pantherpaw9]

That video also explained my next forum question topic, which was about bandwidth.  I see now why the frequency needs a defined bandwidth to take care of the deviations from the carrier frequency.  The radio is simply using the deviations from the carrier frequency to determine how the speaker should vibrate.  The vibration of the microphone causes fluctuations in the carrier frequency and these fluctuations are "de-coded" at the other end so that the speaker reproduces the same "vibrations" (sound).  It's brilliant!  I think I'm very close to understanding this entire mystery.  Correct me if I have totally mis-understood bandwidth.

 

So when I hear people talking about how the FCC has narrowed the bandwidth allowed from 24ish down to 12ish, to make room for more frequencies to be allocated for use, this explains why the sound quality goes down.  Because there is less elbow room for the audio signal to be squeezed in.  So its kind of like the resolution of a digital photograph.  The lower the resolution, the less detail of the original image is visible, thus effecting the quality of the image.  This is really fascinating stuff.

[RCM]

That video also explained my next forum question topic, which was about bandwidth.  I see now why the frequency needs a defined bandwidth to take care of the deviations from the carrier frequency.  The radio is simply using the deviations from the carrier frequency to determine how the speaker should vibrate.  The vibration of the microphone causes fluctuations in the carrier frequency and these fluctuations are "de-coded" at the other end so that the speaker reproduces the same "vibrations" (sound).  It's brilliant!  I think I'm very close to understanding this entire mystery.  Correct me if I have totally mis-understood bandwidth.

 

So when I hear people talking about how the FCC has narrowed the bandwidth allowed from 24ish down to 12ish, to make room for more frequencies to be allocated for use, this explains why the sound quality goes down.  Because there is less elbow room for the audio signal to be squeezed in.  So its kind of like the resolution of a digital photograph.  The lower the resolution, the less detail of the original image is visible, thus effecting the quality of the image.  This is really fascinating stuff.

You're gonna make a good ham!

[Hans]

So, if I want to filter any and all other traffic on that frequency, (and only hear signals going through the repeater), then I would have to change my "Tone Mode" from "Tone" to "T Sql".

I caution against tone squelch when using repeaters. There are repeaters out there that use different tones in to access the repeater and they often tend to put out the same tone as was used to access it. That means one with tone squelch will completely miss traffic using different tones. We have our repeater set up to transmit the same one tone regardless of what tone is used to open the repeater. This is for users with radios that can't set carrier squelch on repeaters (*cough* Midland!).

 

Also, with tone squelch, one cannot hear someone talking on simplex if they don't happen to be using the same tone. I trained my adult children to use the busy light on the radio or use the monitor button before transmitting on our radios with tone squelch enabled. Other than than, busy channel lock out is another option to minimize unintentional interference. We have a fair bit of FRS and GMRS traffic at times in our area.

 

Overall though, I prefer to run carrier squelch when working with repeaters.

 

(If I am repeating myself, no pun intended, I'm multi-tasking at the moment on multiple radio services. )

[pantherpaw9]

I caution against tone squelch when using repeaters. There are repeaters out there that use different tones in to access the repeater and they often tend to put out the same tone as was used to access it. That means one with tone squelch will completely miss traffic using different tones. We have our repeater set up to transmit the same one tone regardless of what tone is used to open the repeater. This is for users with radios that can't set carrier squelch on repeaters (*cough* Midland!).

 

Also, with tone squelch, one cannot hear someone talking on simplex if they don't happen to be using the same tone. I trained my adult children to use the busy light on the radio or use the monitor button before transmitting on our radios with tone squelch enabled. Other than than, busy channel lock out is another option to minimize unintentional interference. We have a fair bit of FRS and GMRS traffic at times in our area.

 

Overall though, I prefer to run carrier squelch when working with repeaters.

 

(If I am repeating myself, no pun intended, I'm multi-tasking at the moment on multiple radio services. )

 

What is carrier squelch?  I think I'm confused again...haha.  Is carrier squelch the same as "T-Sql"??

[Hans]

What is carrier squelch?  I think I'm confused again...haha.  Is carrier squelch the same as "T-Sql"??

Sorry... Carrier squelch is just using the squelch setting (or squelch knob if the radio has one) to silence the static of the RF noise floor. It means running no T-Sql.

[Hans]

I might miss something but the three *basic* modes of squelch in this application:

 

Open Squelch = No squelch at all, hears all of the static of the RF noise floor.

 

Carrier Squelch = A setting or knob adjustment to raise squelch above the RF noise floor. If too high, might miss traffic. If too low, might open up when there is no traffic.

 

Tone Squelch = A CTCSS/PL tone or a DCS to control when the speaker opens to radio traffic.

[pantherpaw9]

I was watching the video again, and there is an image about half way through the video that shows the squelch detector and there is a vertical dimension drawn on the modulated wave in the diagram that is supposed to represent the wave amplitude.  When the term "noise floor" was introduced in this forum discussion in the previous post by Hans, I'm assuming this is related to what the video was trying to explain.  I'm guessing that squelch is simply filtering out signals that are below a certain "power" threshold or signal strength.  Is that correct?  Is the signal's amplitude related to its "strength" or "power"?  If this is true, then the squelch is simply allowing the speaker to emit voice sounds that come from waves that meet a "minumum power level" that is set by the squelch knob?  In other words, it mutes signals that are not at least a minimum "strength"?