DCS vs. CTCSS: Are they different and if so which is used more often
Felix Sieder
Among the many things that I'm trying to learn about scanners is tone
coding via CTCSS/DCS. I have seen that some scanners that I am
considering (eg. Icom R2) only support CTCSS whereas others mention
both. I'm assuming then that these are independent systems and I'm
wondering if one of these (eg. CTCSS) is used much more commonly than
the other? Would it be strongly advisable to get a radio that
supports both rather than just one? If I live in a large urban area
is this a feature that is essential (I wouldn't mind getting the
Bearcat 245XLT but its lack of this feature is a concern...is this a
reasonable concern?) Is this technology more important for
distinguishing/selecting between different agencies using the same
frequency or for reducing intermod from pagers, cell phones... which
don't use CTCSS/DCS. My understanding from a few FAQ's that I have
read is that CTCSS and PL are synonymous (different trade names for
the same technology?) and the same applies to DPL/DCS.
Cheers,
Felix
p.s. If you want to reply via e-mail please change the .xae to .ca
D Stark
news:387f5995....@news.mcgill.ca...
> Hi,
>
> both. I'm assuming then that these are independent systems and I'm
> wondering if one of these (eg. CTCSS) is used much more commonly than
> the other? Would it be strongly advisable to get a radio that
> supports both rather than just one? If I live in a large urban area
> is this a feature that is essential (I wouldn't mind getting the
> Bearcat 245XLT but its lack of this feature is a concern...is this a
> reasonable concern?)
If you can afford a receiver that does both, you should get it because DCS
is becoming more common. There are a limited number of CTCSS tones
available, and in large urban areas it is especially important to have the
flexibility of DCS available for radio users. DCS uses a subaudible
datastream to identify particular users' transmissions to the intended
receiver. It is less prone to false squelch opening than CTCSS.
The BC-245 does not have CTCSS or DCS capability, but can track Motorola and
Ericsson EDACS trunked systems. I have found my BC-245 to be disappointing
as a conventional scanner in an RF-rich environment like downtown Rochester
because of its lack of CTCSS/DCS squelch, but it is an excellent trunk
tracker anywhere.
The only handheld scanners (not transceivers) that offer DCS decoding are
the Relm HS-200 and the Radio Shack PRO-92 (and maybe the 94). The PRO-92
is the only trunk tracker to have this feature (again, maybe the PRO-94
does, too). If a scanner supports DCS, you can count on CTCSS capability as
well.
> don't use CTCSS/DCS. My understanding from a few FAQ's that I have
> read is that CTCSS and PL are synonymous (different trade names for
> the same technology?) and the same applies to DPL/DCS.
CTCSS means Continuous Tone Coded Squelch System, which is the generic
technical name for the subaudible squelch technology. PL is Motorola's
trademark "Private Line" for CTCSS. Another less used trademark is "Channel
Guard" by GE (now Ericsson).
DCS means Digital(ly) Coded Squelch, which is also a generic name. DPL is
"Digital Private Line" - a modified version of Motorola's trademark. I
don't know for sure whether or not Motorola has actually trademarked "DPL"
or if it was made up by customers.
73 de Dave, NF2G
Chuck Rowe
undesired signals. Depending upon your position rewlative to two
users on the same frequency it is also a great way to keep those users
separated. Obviously if one user is hitting you with a stronger
signal, he'll still be able to step on the other user.
And yes, CTCSS and PL are the same thing. PL or Private Line is a
trademark of Motorola.
On Fri, 14 Jan 2000 17:30:41 GMT, fjsi...@microimm.mcgill.xae (Felix
Sieder) wrote:
> Is this technology more important for
>distinguishing/selecting between different agencies using the same
>frequency or for reducing intermod from pagers, cell phones... which
Gary Oakes
similar but instead of subaudible tones uses a digital signal. Allows for up
to 1000 codes in most systems vs 40 +/- for PL.
Also harder for intermod to open squelch.
"Chuck Rowe" <ch...@nospam.latraffic.org> wrote in message
news:3883a12c...@news.earthlink.net...