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Two-Way Radio CTCSS and DCS Codes Compiled by and Formerly Maintained by Robert Meister WA1MIK (SK) Currently Maintained by Mike Morris WA6ILQ.

CTCSS (Continuous Tone-Coded Squelch System) uses sub-audible (below 300 Hz, not necessarily inaudible) tones to activate coded receivers. PL (Private Line) is Motorola's trademarked name for this system. General Electric calls theirs CG (Channel Guard). Other companies used the trade names of Quiet Channel (QC), Private Call (PC), Call Guard (CG) Electronic Tone Squelch (ETS), Quiet Tone (QT) and more.

DCS (Digital-Coded Squelch) uses a 23-bit digital pattern to activate coded receivers. DPL (Digital Private Line) is Motorola's trademarked name for this system. General Electric calls theirs DCG (Digital Channel Guard). Amost everyone else just put "Digital" in front of their trade name and abbreviation.

More information on CTCSS / PL / CG / DPL / DCG can be found in the article at A Historical and Technical Overview of Tone Squelch Systems. (opens in a new browser tab)

VALID MOTOROLA PL LETTER / NUMBER CODES AND TONES

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Code / Hz	Code / Hz	Code / Hz	Code / Hz	Code / Hz	Code / Hz
XZ / 67.Ø	WZ / 69.31	XA / 71.9	WA / 74.4	XB / 77.Ø	WB / 79.7
YZ / 82.5	YA / 85.4	YB / 88.5	ZZ / 91.5	ZA / 94.8	ZB / 97.42
1Z / 1ØØ.Ø	1A / 1Ø3.5	1B / 1Ø7.2	2Z / 11Ø.9	2A / 114.8	2B / 118.8
3Z / 123.Ø	3A / 127.3	3B / 131.8	4Z / 136.5	4A / 141.3	4B / 146.2
5Z / 151.4	5A / 156.7	5B / 162.2	6Z / 167.9	6A / 173.8	6B / 179.9
7Z / 186.2	7A / 192.8	M1 / 2Ø3.53	8Z / 2Ø6.54	M2 / 21Ø.7	M3 / 218.1
M4 / 225.7	9Z / 229.15	M5 / 233.6	M6 / 241.8	M7 / 25Ø.3	ØZ / 254.15
Notes: 1:   69.3 Hz is in the RS-220A and the EIA/TIA-603 standard tone tables, some radios use 69.4 Hz instead (as it better fits the tone sequence), and some radios just skip this tone. It is NOT recommended to use this tone unless you are sbsolutely sure that every radio in your system uses the exact same frequency, either 69.3 Hz or 69.4 Hz. 2:   The tone 97.4 Hz is completely skipped in some equipment, including the MSF5000 Multi-Coded Squelch Module (TLN2420A). 3:   203.5 is in TIA-603, but not in some commercial equipment. 4:   The tone 206.5 Hz is not in TIA-603 and is completely skipped in some equipment, including the MSF5000 Multi-Coded Squelch Module (TLN2420A). 5:   The tones 229.1 Hz and 254.1 are not in TIA-603. Tones shown in red are not standard and are specifically not recommended in the Motorola literature. Tone frequencies above 200 Hz may be audible in some radios and hence are not recommended without testing. Also several government agencies recommend that systems avoid tones above 200 Hz for interoperability as many radios don't have them (or if they do, they can have different combinations of them).

Motorola developed DPL and their list of 83 standard codes (in black below). The DPL codes are specified as a 3-digit octal code (9 bits), which translates to 511 decimal. Trivia: It's actually a 4-digit code (12 bits), but the first digit is always a 4, so it was dropped to keep it simple. Of those 511 possible codes there are only 83 standard codes that do not have an alias code (another code that happens to work just as well). All standard DPL codes have zero alias codes between themselves. Thus they are reliable and trustworthy.

Many of the nonstandard codes have an unbalanced bitstream that can cause an offset of the carrier frequency that can affect both decode-ability and the intelligibility. Long periods of all zeros or ones can cause the timing in the receiving radio to slip. The standardized codes were selected to have sufficient transitions to maintain clock recovery. Some manufacturers have their own proprietary (non-standard) codes, using one can lead to interoperability issues between radios from different brands. Some manufacturers offer the ability to specify your own 3-digit octal number. Some non-standard codes may be more prone to false decodes ("falsing").

Note that some non-standard codes may alias with standard codes or other non-standard codes, meaning that they may use a different code number but use the same underlying data stream. For example, 212, 253, 356 and 521 are all nonstandard codes and they all alias to each other. Some standard codes have aliases to one or more non-standard codes; example: standard code 023 will alias to 707, 375 and 047. Some non-standard DPL codes will alias to as many as as eight codes.

Ø23	Ø25	Ø26	Ø31	Ø32	Ø43	Ø47	Ø51	Ø53	Ø54	Ø65	Ø71	Ø72
Ø73	Ø74	114	115	116	122	125	131	132	134	143	152	155
156	162	165	172	174	2Ø5	212	223	225	226	243	244	245
246	251	252	252	261	263	265	266	271	3Ø6	311	315	325
331	340	343	346	351	356	364	365	371	411	412	413	423
425	431	432	445	446	452	455	464	465	466	5Ø3	5Ø6	516
521	525	532	546	552	564	565	6Ø6	612	624	627	631	632
645	652	654	662	664	7Ø3	712	723	725	726	731	732	734
743	754	766
Codes shown in black are the 83 standard codes. Codes shown in red have been seen in other code lists and other literature. The red codes are not standard and are not recommended for use. All codes that are not in the above table (example: Ø27, Ø28, etc.) are also not standard and are not recommended for use.

These DPL codes were extracted from a Motorola MSF5000 RSS Help file, other manuafcturers code lists and other sources.

Additional information was supplied by Eric WB6FLY (SK) and Mike WA6ILQ.

PL, DPL, RSS, CPS and MSF5000 are trademarks of Motorola, Inc.

Each of the 4 radios below offers 104 DPL codes!

Here are the CTCSS and DCS tables from the Icom IC-91AD handheld radio manual:

Here are the CTCSS and DCS tables from the Kenwood TH-f6A handheld radio manual:

Here are the CTCSS and DCS tables from the Yaesu VX-8R handheld radio manual:

Midian Electronics has a handy PDF file that contains details of just about every tone signaling scheme used. It can be downloaded by clicking here.

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This article first posted 28-Nov-2007

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This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.