Setting Repeater Tones Configuration

[VE7AXU]

I am configuring a Yaesu FT-7800R for repeater operation. The repeater requires a tone of 110.9 but the configuration menu for the my radio is vague - offering me several choices of tones. The offer a CTCSS and a DCS tone option - which one would I pick? In the case of CTCSS they further offer to encode or decode or encode/decode ... a little confusing. What are the differences and which one am I likely to need?

VE7AXU (John)

[KA4POL]

You need CTCSS. If the repeater requires it, you need to transmit, i.e. encode, that tone.

Only when you want to limit your reception to signals carrying the tone you would want to decode.

DCS is basically the same principle but a technically different solution.

[WB6DGN]

DCS is basically the same principle but a technically different solution.

To expand a little bit on KA4POL's comment.  DCS or DPL is a three digit octal code that is transmitted continuously, like CTCSS, and performs the same function.  Instead of a low frequency audio tone, it transmits a three digit octal number which, when it matches the code set in the radio, unlocks the squelch.  So, functionally they are identical though the methodology is different as KA4POL noted.  You can tell which is being used by the form of the number; a DCS code might be 023, for example while a CTCSS tone might be 110.9.
As for which option to pick, most hams around here pick the "ENCODE" option which transmits the tone to enable the repeater but the receiver hears all traffic on the frequency.  That way you will be able to talk on the repeater but will not miss a call from someone who isn't transmitting the tone/code.  Just a little extra information; hope it helps.
Tom

[KA4POL]

That way you will be able to talk on the repeater but will not miss a call from someone who isn't transmitting the tone/code. 

Not to let VE7AXU think the signal is retransmitted via the repeater, it is not retransmitted and most repeaters do not send CTCSS tones. If you use the tone on receive (decode) you will not hear anything unless the transmitting station has the tone in its signal.

[KE3WD]

Round Number with no decimals will be a DCS (ex:  023).

If, on the other hand, the repeater guide or whatever you're using has a two or three digit number followed by decimal point and more numbers, it is CTCSS (ex:  110.9).

[KB1LKR]

DCS is a digital data string, CTCSS is a single, low frequency audio tone. DCS appears to not be common for amateur repeater use, at least in the Northeast US, but sometimes used for FM analog public safety etc. Maybe it will become more common in the future, as, at one time, long ago, CTCSS was uncommon for amateur use; maybe not.

Both achieve the same result however.

Likely you'll find encode ("Tone" or "T" for Yaesu as I recall), is sufficient.
Encode/decode "Tone Squelch" or "TSQ" for Yaesu IIRC, is only needed if you're picking up multiple repeaters on a single frequency pair and want to hear only one of them, possible if mobile and in very flat terrain (TX panhandle comes to mind, man is that FLAT!) or at very high local elevations -- Pikes Peak auto road, Mt. Washington auto road, etc.