Understanding CTCSS and DCS

[@stephenmitchell7860]

👍 Thank you so much for posting this. This just connected the dots and now I'm receiving lima charlie!

[@judeogbonna9884]

Super clear simple and straight. Thanks

[@davidhartinger636]

Nice work. Makes CTCSS and DCS more easily understood.

[@johnk1204]

Clear and concise. Thanks!

[@pauldenisowski]

Thank you!

[@wisteela]

Very informative. Great explanation of how DCS works.

[@pauldenisowski]

Thanks!

[@gregdomingo8207]

Wow thanks! This is crystal clear explanation.

[@jaybarr3307]

Very good, clear explanation. Thank you!

[@jluke6861]

Thank you for your informative video

[@pablo_fernandez]

Thank you for the clarity in this video.

[@حضرمون]

Thanks for simplifying. I have learned a thing or two from this video. 🙏🙏

[@pauldenisowski]

Thanks!

[@philhamlin1903]

Nicely done. Ready helped my understanding.

[@pauldenisowski]

Glad it was helpful - thanks for the feedback!

[@andreiamg8393]

Squelch filter - I believe it is a high pass filter to remove the

[@pauldenisowski]

Yes, it should have been "high pass" (since it removes the lower frequency components). Thanks - good catch!

[@MarianoCrivello1]

Thank you for this presentation.

[@TurboNorm]

Super helpful for a new guy.

[@pauldenisowski]

Thanks!

[@jesimpson4934]

Truly excellent, thank you!

[@violtailer9964]

4:55 not low pass, but high pass filter is used to remove frequencies belof some f0

[@richiec7602]

Great, easy to understand explanation of these tones. I have a question: In some radios they state that there are “privacy tones” or “sub-channels”. I believe that these are are either CTCSS or DCS tones but there is no mention of them in the accompanying literature. Am I correct?

[@pauldenisowski]

Yes. I've often seen CTCSS / DCS referred to as "privacy tones" This is a very misleading term, since neither CTCSS nor DCS provide any "privacy" at all: that is, they do not encrypt or obscure transmissions (unlike, say, the voice inversion scrambling found on some older analog radios). "Sub-channel" is a little less problematic in that you can use CTCSS/DCS to create "talkgroups" or "channels" where users only hear transmissions from other people using the same tone/code, but keep in mind that this is different from the "talkgroups" or "channels" in digital trunked radio technologies like P25. Hope that helps!

[@jims408]

Many thanks for this; very helpful!

[@pauldenisowski]

Thanks! Appreciate the feedback!

[@alnofaly11]

I work in an isolated place in the Middle East, where I use the Alinco DR-B185 that has a DCS feature, where I only pick up a full signal for my colleagues without being able to hear them talking! Is there any clarification on that please?

[@muhammadazharhairuddin9457]

Excellent explanation, very helpful

[@desipityu]

Thanks !

[@quotidien_]

Excellent. Thank you.

[@pauldenisowski]

Thank you!

[@richpaul8132]

Excellent explanation! Now, I need to try and put it into a real-world application. The first thing I think I would want to do is to scan for any CTCSS or DCS users, no? I mean, I don't really need to speak to a user, (at least, not at first), but I only want to confirm that my SR 955HPC V2 is able to receive from someone using that system. I've got a long way to go before I plan to attempt transmitting to a CTCSS/DCS user. For now, I'd be happy just confirming that I have found and am receiving a transmission from a CTCSS or DCS user. Thanks for the video! Rich

[@gianluigiredolfini6154]

Super clear thanks for a job well done!

[@drakeblackk]

Well, i never really got into dcs and stuff, i just got a better radio (Yaesu 7800E) and i was thinking about if there is any code that can be used to communicate in private, without people hearing it without these turned on? Like when i test with my UVK5 and Yaesu, so noone can hear that only between the handheld and the Yaesu

[@SergeantExtreme]

What kind of monster would actually WANT to turn off the squelch tail?? It's part of radio tradition!

[@pauldenisowski]

(laughs) I agree with you completely. Not the same without the squelch tail.

[@DucatiMTS1200]

Excellent explaination.

[@Nab-Asn2803]

Thank you so much for this great vedio

[@pauldenisowski]

Thanks!

[@jeffbornes3986]

Great explanation!

[@isaacu]

Super informative. Thank you for this.

[@ulfjakob]

Good stuff!

[@CM-ef8fu]

Thank you!

[@srviejo2298]

With all due respect, this video is in error at time stamp 4:50, where the narration indicates that a low pass filter routes audio to the speaker. This would result in only the CTCSS tones being rendered at the speaker. In practice, a low pass filter routes audio from the discriminator to the tone decoder, but a band pass (often 300 Hz to 3,000 Hz) routes audio to the speaker, and a high-pass filter (above the band-pass filter frequency range) routes audio to the noise gate for non CTCSS/DCS squelch behavior.

[@ErrorMargin]

Assuming simplex (not using a repeater) radio to radio transmission, how do noise squelch and user squelch interact? Does the signal have to break noise squelch before the radio will check for the tone or code to see if user squelch should be opened? Or is it the other way around? Would it make sense to turn off noise squelch when using user squelch so that if the signal is strong enough for the radio to detect the user squelch tone or code then squelch is opened regardless of signal strength or noise?

[@mattvikich3767]

Awesome vid. Can two radios on the same dcs channel be used threw a repeater on duplex? Im guessing everone would hear the "tail" of the repeater which could get annoying for them?

[@HectorSanchez-ik9ny]

GRACIAS POR LA EXPLICACIÓN. :)

[@syedalihaider7144]

Thank you Sir

[@frequencywatchers]

WHat A GREAT VIDEO, Explanation is 10/10 !@!!

[@Drawsome2478]

Now how do I use this knowledge to get on target’s radio frequency

[@asetyylisalisyyli]

Anyone know what is the center frequency of the FSK in DCS?

[@RuckProductions35]

Brilliant

[@yumenowinds]

Which is better?? DCS od OFF

[@gladyslimbaniacamachodecar8285]

Se puede traducir al español, gracias

[@pauldenisowski]

Gracias por la sugerencia! Algunos de nuestros videos ya fueron traducidos en español (por ejemplo "Introducción a metodologías para radio localización" kzbin.info/www/bejne/jWHQgKiPqrmfZrM).

[@philkarn1761]

You meant to say that the tone is removed by passing the audio through a *high* (not low) pass filter before going to the speaker.

[@pauldenisowski]

Yep, clearly I mis-spoke there :)

[@tesayseng]

CTCSS and DCS can increase transmission or received range? i use baofeng 145.500 7.5w power frequency with DCS range is longer then 168.500 8w power frequency with CTCSS (data test by JK-560s). can you explain about that? thank you for help

[@pauldenisowski]

Neither CTCSS or DCS should affect the achievable transmission range per se. The one place where it might make a difference would be at the very edges of the Tx/Rx range -- if the receiver cannot properly detect / demodulate the CTCSS tone or DCS code (due to poor SNR), then it will not break squelch and the effective "range" is reduced. I haven't made any proper measurements of the difference, but I would *assume* that in these kinds of low-SNR situations, CTCSS is actually easier to decode than DCS. Regarding your specific example: I'm not sure how you're measuring "range" (over-the-air?) or how much "longer" the range is (meters? kilometers?). The most accurate measurement would probably be a field-strength measurement (V/m or similar) made over-the-air near the radio. I suspect that the difference you're seeing in "range" might be related to frequency: the antenna you have on your radio might be a more efficient radiator / receiver in the 2m amateur band (145.500) compared to outside of that band (168.500), and this would definitely affect the radiated and received power. I would also want to test using the same frequency and power level, only changing whether CTCSS or DCS (or neither) is used. Hope some of that is helpful!

[@tesayseng]

@@pauldenisowski thank you for your help

[@jonjeffries3265]

Just a quick question here.. can I use my 440 HT (Yaesu VX5) communicate with simplex on a gmrs HT..? (Wouxun KG 805G)

[@pauldenisowski]

Well, that's not really related to CTCSS or DCS, but the short answer is that two radios have to share some frequency range to communicate. The VX5 is an amateur radio transceiver and although it has a wideband receive function, it can't (normally) transmit outside of the amateur bands. The Wouxun radio is nominally a GMRS radio, and these frequencies don't overlap with the amateur radio bands. That said, it *appears* that the Wouxun has a transmit frequency range that includes the amateur band, so it might work. I do feel the need to point out that transmitting on amateur radio frequencies without a license and without proper identification is a violation of FCC rules. :)

[@jonjeffries3265]

@@pauldenisowski thank you so much for your time n knowledge, (and I did watch your video clip of couple times cuz I am interested in CTCSS and DCS), and for making an exception in answering my question. I was first ticketed in 2000 for amateur tech no code, KG6ASF, and reviewing for my renewal (hope I can keep the same call sign) I received my gmrs ticket approximately 1 month ago WRNR411.

[@pauldenisowski]

@@jonjeffries3265 No problem at all - always happy to answer questions. :) Good luck and 73! Paul, KO4LZ

[@WaschyNumber1]

Nice 👍🖖

[@susceptibility_]

I wish your instrument GUI's were as simple to understand as this video

[@JustinH95]

Radios are so badass

[@cognitivedissonance7539]

Narrated by James Woods. Seriously.

[@pauldenisowski]

(laughs) I consider that a compliment - thank you!

[@RuthLopez-j4z]

Lavon Bypass

[@BharathiS-ib9ux]

RS👎