Understanding CTCSS and DCS
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- čas přidán 1. 06. 2024
- This video explains the basic technical principles behind CTCSS (continuous tone coded squelch system) and DCS (digitally coded squelch) as well as how they are used in analog radio systems.
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Index
00:15 About squelch
1:45 User squelch and talk groups
2:10 Squelch and repeaters
3:35 CTCSS (continuous tone coded squelch system)
4:21 CTCSS tones
4:57 DCS (digitally coded squelch)
5:42 DCS codeword example
6:03 Standard DCS codes
6:48 Polarity inversion
7:20 Turn off code
8:10 Summary - Věda a technologie
👍 Thank you so much for posting this. This just connected the dots and now I'm receiving lima charlie!
Clear and concise. Thanks!
Thank you!
Super clear simple and straight. Thanks
Thank you for your informative video
Excellent. Thank you.
Thank you!
Very informative. Great explanation of how DCS works.
Thanks!
Wow thanks! This is crystal clear explanation.
WHat A GREAT VIDEO, Explanation is 10/10 !@!!
Nice work. Makes CTCSS and DCS more easily understood.
Thanks for simplifying. I have learned a thing or two from this video. 🙏🙏
Thanks!
Very good, clear explanation. Thank you!
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
Super helpful for a new guy.
Thanks!
Thank you!
Squelch filter - I believe it is a high pass filter to remove the
Yes, it should have been "high pass" (since it removes the lower frequency components). Thanks - good catch!
Nicely done. Ready helped my understanding.
Glad it was helpful - thanks for the feedback!
Thank you so much for this great vedio
Thanks!
Thank you for this presentation.
Truly excellent, thank you!
Super clear thanks for a job well done!
Excellent explaination.
Great explanation!
Many thanks for this; very helpful!
Thanks! Appreciate the feedback!
What kind of monster would actually WANT to turn off the squelch tail?? It's part of radio tradition!
(laughs) I agree with you completely. Not the same without the squelch tail.
Good stuff!
Excellent explanation, very helpful
Thank you Sir
4:55 not low pass, but high pass filter is used to remove frequencies belof some f0
GRACIAS POR LA EXPLICACIÓN. :)
Super informative. Thank you for this.
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?
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!
Radios are so badass
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?
Nice 👍🖖
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?
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
Now how do I use this knowledge to get on target’s radio frequency
Anyone know what is the center frequency of the FSK in DCS?
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
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!
@@pauldenisowski thank you for your help
Just a quick question here.. can I use my 440 HT (Yaesu VX5) communicate with simplex on a gmrs HT..? (Wouxun KG 805G)
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. :)
@@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.
@@jonjeffries3265 No problem at all - always happy to answer questions. :) Good luck and 73! Paul, KO4LZ
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.
Yep, clearly I mis-spoke there :)
I wish your instrument GUI's were as simple to understand as this video
Se puede traducir al español, gracias
Gracias por la sugerencia! Algunos de nuestros videos ya fueron traducidos en español (por ejemplo "Introducción a metodologías para radio localización" czcams.com/video/W0mOuYuTl0Q/video.html).
Narrated by James Woods. Seriously.
(laughs) I consider that a compliment - thank you!
RS👎
Witch is better to use ?
CTCSS is much more common, but DCS has better functionality :)