DCS ???? Please Help!!!

[lifesaver247]

What's up!

Can sombody explain DCS and what it cam be used for? I am trying to set up a vertex vx-150 with the computer software. I am new to programing although not new to using a radio. I work as a full time EMT in Carroll County, Indiana. Do I need this feature? Because the main EMS channel that I need has a PL of 82.5. Here's the thing that I don't know, what about all the other channels that I want to scan and possibly use to report public safty issues to other dispach centers (since I am a public service employe).

Please Help,

Thank You!!!!!!

 

[INDY72]

DCS refers to Digital Coded Squelch... AKA DPL or Digital Private Line from Motorola,... It is the digital version of PL....

PL is CTCSS Continous Tone Coded Squelch System, using a subaudible tone to control who is on a radio system.
DPL is CDCSS Continous Digital Coded Squelch System which uses a subaudible digital code for the same purpose.

Most Mobile, and Portable radios can be programed for multiple frequencies, and PL's and DPL's.

PL's are usually expressed as a frequency in Hz such as 82.5.
DPL is expressed as an octal code such as D412.

Both methods are used for the same thing, to prevent interference on a frequency.

All you need to do to use other sytems besides your own is to know the frequency, and the correct PL or DPL tone/code. This can then be programmed in by a radio tech, or you if you know how vias a PC and RIB in the radio's RSS.

This can also be done by you if you have a keypad programmable radio.

For example:
My County's VFD's are all dispatched on our 911 chan which is 155.9550 MHz with DCS of D532. For interop we have the surrounding counties Hi Band EOC freqs programmed in... Example: Lincoln County EOC- 155.8950 MHz, with CTCSS of 203.5 (PL), Franklin County EOC-154.3700 MHz with a CTCSS of 92.7 , and Kings Daughters Medical Center Ambulances- 155.4000 MHz, with CTCSS of 82.5... and so on and so forth.. we also have the Sheriff's freq of 155.1300 MHz, with DCS code D532

Hope this clears things up.

 

[lifesaver247]

More on Programing

OK, that really helps! And I thank you milf for all of it.Programing

I do have a few more questions if someone would be kind enough to spend some time. If a frequency uses DCS then would it be included in the information provided by radioreference.com? See this web page for example. http://www.radioreference.com/modules.php?name=RR&ctid=700 This the county where I work. If the PL tone is not filled in what does this mean?

Now, In the programing software that I have for this radio, there is a spread sheet format for all frequencies that is possible. Included, is the option for each frequency to be programmed in a few ways. From left to right it reads, RX, TX, Offset Frequency, Offset, Name, Tone Mode, CTCSS Tone, DCS Cone, Narrow FM, Scan Skip, and Clock Shift.


This is what I understand and do not understand.

RX and TX - This is self explanitory.

Offset Frequency - How do you know what to set it as? 600 kHz - 3,000 kHz

Offset - This is the options: Simplex, Minus, Plus, and Odd. How do you know what your channels are? Aspecially say if you are going on a trip and want to pre program all channels.

Name - This is alpha numeric for each channel.

Tone Mode - Here are the options: Off, CTCSS Enc, CTCSS Enc/DEC, DCS. As mentioned earlier, we use a PL tone, but how do you know what other areas use? And what is CTCSS Enc/DEC? Our Channel uses CTCSS Enc and I know that just by trial and error.

CTCSS Tone - I think that I understand

DCS Code - I think that I understand

Narrow FM - What is this? Does this have to do with the Mode that is listed here
http://www.radioreference.com/modules.php?name=RR&ctid=700

Scan Skip - I Understand

Clock Shift - I Have no Idea!


Well, as you can see I am full of questions! I just want to be able to understand this radio and the concept better. If you do not want to help I understand, I am getting a little time consuming. I just have never programmed anything and have always had someone else do it. I just decided to get this radio setup so that I have control now.

Please Help if you can,

Thank You All!!!!!!!

 

[W4KRR]

The offset is the difference between the repeater input frequency and the repeater output frequency. On the 2 meter ham band, it's + or - 600 khz. On the 440 MHz ham band, it's + or - 5.00 MHz. It's also +5.00MHz for the UHF public safety band, 450-470 MHz. That is, if the base or repeater frequency is, for example, 460.400, the offset is +5.00MHz, and the input to the repeater is 465.400. In the UHF "T" band, 470-512MHz, the offset is +3.00 MHz. In the VHF high band, there is no standard offset, it can be almost anything.

As for the PL tone, you will need it if you intend to transmit on the system. The squelch on the other radios in the system will open only if the correct PL tone is present. For monitoring only, you can use it, but it isn't necessary just for listening.

Do you intend to transmit on the VX-150 as an EMT? I should point out that the VX-150 isn't FCC type accepted for use outside the ham bands. It will work, (assuming it's been modified) and what you do with it is your business, but I'm sure others will point this out as well.

 

[INDY72]

As to what it means if the system shown in the DB does not have PL or DPL listed, it means no one has submitted the info for it yet. Once we know the right tone/code,.. then we add it to the DB.

 

[lifesaver247]

So if it is not in the database then that does not mean that there is not a PL tone or DCS Code?

Yes I did mod the radio and it has been tested and properly works. Also, If I am using the radio for VHF only then the offset is not applicable to my situation? I just want to get this thing figured out for work and then work on the options. Ok, so is there a "best" offset to set the VHF frequencies at?

I am just trying to get this all strait in my head. Please if anyone has more info and time I would like as much info as I can get.

Thank You All!!!!

 

[INDY72]

Correct it does not mean there isn't one, considering that most radio systems use iether CTCSS, or CDCSS. As to the offset you mention,... You will need both the input frequencies and output frequencies,.. though you need to find out what PL/DPL is used on the freqs your going to use.

You can find out the right ones by talking to the Communications Officers for your agency, or the radio techs as they are the trained proffessionals that work on and with the radios on the system your going to be using.