Tone & Signaling Formats

CTCSS/PL

Continous Tone Coded Squelch (CTCSS) aka PL, Private Line™, & Channel Guard™ is used to differentiate each user on a single frequency. A sub audible tone is sent continuously during each transmission. Example Police Dept. 1 may use 131.8, Police Dept. 2 may use 107.2. It does not offer a "Private Channel" as many radio salesman would like the end user to belief. It is simply a way for multiple users to share the same frequency without hearing each others units. It does not allow multiple simultaneous conversations.

The chart below outlines the commonly used designators for the different PL tones.

The Wulfsburg Flexcomm is a frequency agile radio covering 30-512MHz commonly used on Aero-Medical helicopters. The tone # is programmed in when needed, and is often given on dispatch "Ground contact Engine 3-1-1 on 46 decimal 46, tone #14". This is a good way to find PL's for agencies to use with scanners capable of PL.

Tone/Hz	Motorola	Wulfsburg	Icom	Tone/Hz	Motorola	Wulfsburg	Icom
67.0	XZ	1	1	136.5	4Z	25	20
71.9	XA	2	2	141.3	4A	26	21
74.4	WA	3	3	146.2	4B	27	22
77.0	XB	4	4	151.4	5Z	28	23
79.7	WB	5	5	156.7	5A	31	24
82.5	YZ	6	6	162.2	5B	32	25
85.4	YA	7	7	167.9	6Z	33	26
88.5	YB	8	8	173.8	6A	34	27
91.5	ZZ	11	9	179.9	6B	35	28
94.8	ZA	12	10	186.2	7Z	36	29
97.4	ZB	13		192.8	7A	37	30
100.0	1Z	14	11	203.5	M1	38	31
103.5	1A	15	12	206.6	8Z
107.2	1B	16	13	210.7	M2		32
110.9	2Z	17	14	218.1	M3		33
114.8	2A	18	15	225.7	M4		34
118.8	2B	21	16	229.1	9Z
123.0	3Z	22	17	233.6			35
127.3	3A	23	18	241.8			36
131.8	3B	24	19	250.3			37
69.3	WZ			254.1	0Z

DPL

Digital squelch, or DPL, uses a small sub-audible digital code versus a sub-audible tone. You can have regular or inverted codes. This results from the electronics & system used to send the digital code & how it is recovered in the radio. This is not the forum to discuss the technical operation of DPL, suffice it to say that you get 2 codes for each of the standard DPL codes, normal & inverted. The chart below outlines both.

Code	Inverted	Code	Inverted	Code	Inverted	Code	Inverted
023	047	155	731	325	526	516	432
025	244	156	265	331	465	523	246
026	464	162	503	332	455	526	325
031	627	165	251	343	532	532	343
036	172	172	036	346	612	546	132
043	445	174	074	351	243	565	703
047	023	205	263	364	131	606	631
051	032	212	356	365	125	612	346
053	452	223	134	371	734	624	632
054	413	225	122	411	226	627	031
065	271	226	411	412	143	631	606
071	306	243	351	413	054	632	624
072	245	244	025	423	315	654	743
073	506	245	072	431	723	662	466
074	174	246	523	432	516	664	311
114	712	251	165	445	043	703	565
115	152	252	462	446	255	712	114
116	754	255	446	452	053	723	431
122	225	261	732	454	266	731	155
125	365	263	205	455	332	732	261
131	364	265	156	462	252	734	371
132	546	266	454	464	026	743	654
134	223	271	065	465	331	754	116
143	412	274	145	466	662
145	274	306	071	503	162
152	115	311	664	506	073
032	051	315	423

DTMF Paging & ANI

Standard Dual Tone Multi Frequency (DTMF) aka Touch-Tone™ tones are used for both paging and Automatic Number Identification (ANI). DTMF is also used to activate features of some radio systems like phone patches, remote receivers/transmitters, or to activated alarms remotely.

DTMF ANI will sound like a very quick series of tones which may start, end, or start & end each radio call.

DTMF format paging sends digits for 100ms, 100ms off. Number of digits depends on system, usually at least 4 digits.

Knox format is similar to DTMF, uses different tones though, and is primarily used as a means to unlock special lock "Knox"boxes for fire departments.

	DTMF Tones
	1209	1336	1477	1633
697	1	2	3	A
770	4	5	6	B
852	7	8	9	C
941	*	0	#	D

	Knox Tones
	1052	1162	1297	1430
606	1	2	3	A
672	4	5	6	B
743	7	8	9	C
820	*	0	#	D

Digital ANI

Digital Automatic Number Identification (ANI) is way to send information back to the dispatcher. This information can contain the radio ID, users ID, vehicle location via Automatic Vehicle Location (AVL), be used as an emergency indicator or "Man Down" alert.

There are 5 digital ANI formats presently being marketed, these include Motorola MDC-1200™, GE/Ericsson GE-Star™, Transcrypt Flash Call, Control Signal, and Midian Zap. All 4 formats are proprietary & incompatible with the other. These systems also allow for stolen radios to be "stunned": to disable them, & to be activated for the dispatcher to listen in to the area around the radio.

You will know if a system in your area is using these, as it is a short digital burst that begins, ends, or both each radio conversation. Sounds like a short schreech.

5/6 Tone Paging & ANI

This format is used for both tone pager activation and for Automatic Number Identification (ANI). This format was originally developed for tone only pages using the MetroPage™ format (Metro PageBoy™ etc.). Pagers can have 2 addresses per capcode. Thus you could get two different alerts to the pager with two different meanings, Tone 1 Call Home, Tone 2 Call Office etc..

Today most of the 5/6 Tone pagers are gone, but the format lives on in ANI needs for Public Safety. ANI allows for the number of the radio to be sent on each transmission. You may have heard it as a long tone & a quick series of tones, or just a quick series of tones when each user starts a radio call.

The chart below outlines the tones used for the 6 internationally used formats. CCIR & ZVEI's are most commonly used in Europe. EIA/MetroPage is used in the US.

Tone #	EIA	CCIR	ZVEI1	ZVEI2	ZVEI3/DZVEI	PZVEI	EEA
0	600	1981	2400	2400	2200	2400	1981
1	741	1124	1060	1060	970	1060	1124
2	882	1197	1160	1160	1060	1160	1197
3	1023	1275	1270	1270	1160	1270	1275
4	1164	1358	1400	1400	1270	1400	1358
5	1305	1446	1530	1530	1400	1530	1446
6	1446	1540	1670	1670	1530	1670	1540
7	1587	1640	1830	1830	1670	1830	1640
8	1728	1747	2000	2000	1830	2000	1747
9	1869	1860	2200	2200	2000	2200	1860
A	2151	2400	2800	885	825	970	1055
B	2435	930	810	810	740	810	930
X/C	2010	2247	970	740	2600	2800	2247
D	2295	991	885	680	885	885	991
R/E	459	2110	2600	970	2400	2600	2110
F	No Tone	1055	680	2600	680	680	2400
Timing
Preamble	673ms	673ms	673ms	673ms	673ms	673ms	673ms
Gap	65ms	65ms	65ms	65ms	65ms	65ms	65ms
Tone	33ms	40ms	100ms	100ms	100ms	100ms	100ms
X Tone	65ms	40ms	100ms	100ms	100ms	100ms	100ms

The Preamble is used as a battery saving mechanism, similar to todays digital pagers, thus the pager looks for its preamble, if not heard it shuts off to standby mode.Not all systems use the Preamble, that is why its called 5/6 tone paging. You may only have 5 tones when not using the Preamble.

In 5/6 tone paging a consecutive number is never sent. thus a pager with capcode 1-12344, would be sent using the a Preamble tone of 1/600Hz, followed by a 65ms gap of silence, then 2/882Hz, 3/1023Hz, 4/1164Hz each 33ms long, the second four is transmitted using the R (Repeat) Tone of R/459Hz.

The second address of a pager is activated by sending the X tone after the pagers capcode, thus 1-12345X.

The chart above inlcudes both 5/6 Tone & HSC Tones. For 5/6 Tone pagers only Tones 0-9, X, & R are used. Tones A-F are for use in HSC Pagers and 5/6 Tone ANI systems.

Hexadecimal Sequential Code (HSC) Paging

This format is an extension of the 5/6 tone paging format to allow for numeric display pagers versus the early tone only pagers using 5/6 tone formats. An example of these pagers is the Motorola BPR-2000. This format has been replaced by newer digital formats, and is only used on Public Safety systems, private systems, and some very small common carrier systems. New pagers are not available, used pagers are still available.

For EIA/MetroPage the timing of the tones is increased to 65ms. Upto a 12 digit message may be sent.

Tone #	EIA
A	2151
B	2435
C	2010
D	2295
E	459
F	No Tone

2 Tone Sequential Paging

This is the format most listeners will be familiar with. This format is the most common method to alert volunteer ambulance & fire departments. It has various names including QuickCall II™ & Type 99™. This format also goes by 1+1 in some radio equipment. This format uses 2 tones, A & B for standard paging, a third & fourth tones C & D are used to provide group call and second call to each pager.

This format uses a timing of Tone A for 1 second & Tone B for 3 seconds. For All Call Tone B is sent for 8 seconds, where all pagers have the same A tone. Group Call with Tone A & C, and Second Code Call with tone A & D.

The original form of this system, QuickCall I™ uses 4 tones, and is commonly called 2+2 paging. Where Tones A & B are sent for 1.25 seconds, and tone C & D are sent for 1.0 second. The 2+2 format only uses tones from the Motorola groups of A, B, & Z.

The GE version of this format uses Tone A 1.0 second, a gap of 180 ms., and Tone B 3 seconds.

The tables below outline the tones of the various groups for each series by Motorola & GE.

Tone#	Mot. 1	Mot. 2	Mot. 3	Mot. 4	Mot. 5	Mot. 6	Mot. 10	Mot. 11	GE A	GE B	GE C
0	330.5	569.1	1092.4	321.7	553.9	1122.5	1472.9	1930.2	682.5	652.5	667.5
1	349.0	600.9	288.5	339.6	584.8	1153.4	1513.5	1989.0	592.5	607.5	712.5
2	368.5	634.5	296.5	358.6	617.4	1185.2	1555.2	2043.8	757.5	787.5	772.5
3	389.0	669.9	304.7	378.6	651.9	1217.8	1598.0	2094.5	802.5	832.5	817.5
4	410.8	707.3	313.0	399.8	688.3	1251.4	1642.0	2155.6	847.5	877.5	862.5
5	433.7	746.8	953.7	422.1	726.8	1285.8	1687.2	2212.2	892.5	922.5	907.5
6	457.9	788.5	979.9	445.7	767.4	1321.2	1733.7	2271.7	937.5	967.5	952.5
7	483.5	832.5	1006.9	470.5	810.2	1357.6	1781.5	2334.6	547.5	517.5	532.5
8	510.5	879.0	1034.7	496.8	855.5	1395.0	1830.5	2401.0	727.5	562.5	577.5
9	539.0	928.1	1063.2	524.6	903.2	1433.4	1881.0	2468.2	637.5	697.5	622.5
A
B
Diag.	569.1	979.9	569.1	569.1	979.9	979.9			742.5	742.5	742.5

Tone #	Mot. A	Code	Mot. B	Code	Mot. Z	Code
0	358.9	CA	371.5	CB	346.7	CZ
1	398.1	DA	412.1	DB	384.6	DZ
2	441.6	EA	457.1	EB	426.6	EZ
3	489.8	FA	507.0	FB	473.2	FZ
4	543.3	GA	562.3	GB	524.8	GZ
5	602.6	HA	623.7	HB	582.1	HZ
6	668.3	JA	691.8	JB	645.7	JZ
7	741.3	KA	767.4	KB	716.1	KZ
8	822.2	LA	851.1	LB	794.3	LZ
9	912.0	MA	944.1	MB	881.0	MZ
A	1011.6	NA	10471.	NB	977.2	NZ
B	1122.1	PA	1161.4	PB	1084.0	PZ
Diag.	979.9		979.9		979.9

QuickCall I codes may be used in two different forms: DZJZ-EZHZ or DJ-EH. They both have the same meaing, the first just specifices the tone series each time. The second assumes a given tone sereis is used, and known to the agencies using the system. The Diagonal Tone is not used in 2+2/QuickCall I systems, but when the A, B & Z series is used in the 1+1/2 Tone format this tone is used.

Plectron Paging

This is an early system used to alert many volunteer type organizations. This system uses a single tone sent,or two tones sent in one of two formats. The chart below are the standard Plectron tones.

Single Tone - 3 seconds of A tone
Slow Duotone - 3 seconds of A, .25 seconds of B
Fast Duotone - .75 seconds of A, .25 seconds of B

Tone #	Freq.	Tone #	Freq.	Tone #	Freq.	Tone #	Freq.
	282.2		517.8	11	992.0	25	1820.0
	294.7		540.7	12	1036.0	26	1901.0
	307.8		564.7	13	1082.0	27	1985.0
	321.4		589.7	14	1130.0	28	2073.0
	335.6		615.8	15	1180.0	29	2164.0
	350.5	2	672.0	16	1232.0	30	2260.0
	366.0	3	701.0	17	1287.0	31	2361.0
	382.3	4	732.0	18	1344.0	32	2465.0
	399.2	5	765.0	19	1403.0	33	2575.0
	416.9	6	799.0	20	992.0	34	2688.0
	435.3	7	834.0	21	1530.0	35	2807.0
	454.6	8	871.0	22	1598.0	36	2932.0
	474.8	9	910.0	23	1669.0		3062.0
	495.8	10	950.0	24	1743.0		1957.0

Reach Tone Paging

REACH format is billed as a "High Speed" paging system very similar to the 2 Tone Sequential systems by Motorola & GE. REACH format uses a A tone of 2.0 seconds, and a B tone of 0.8 seconds. Group Call is 5 seconds. REACH tones are outlined in the table below.

Tone #	Freq.	Tone #	Freq.	Tone #	Freq.	Tone #	Freq.
0	3960.0	15	2354.0	30	1400.0	45	832.0
1	3824.0	16	2274.0	31	1352.0	46	804.0
2	3694.0	17	2196.0	32	1306.0	47	776.0
3	3568.0	18	2121.0	33	1261.0	48	750.0
4	3446.0	19	2049.0	34	1219.0	49	725.0
5	3329.0	20	1980.0	35	1177.0	50	700.0
6	3215.0	21	1912.0	36	1137.0	51	676.0
7	3106.0	22	1847.0	37	1098.0	52	653.0
8	3000.0	23	1784.0	38	1061.0	53	631.0
9	2898.0	24	1723.0	39	1025.0	54	609.0
10	2799.0	25	1664.0	40	990.0	55	588.0
11	2704.0	26	1608.0	41	956.0	57	549.0
12	2612.0	27	1553.0	42	923.0	58	530.0
13	2523.0	28	1500.0	43	892.0	59	512.0
14	2437.0	29	1449.0	44	862.0	60	495.0

Zetron Tone Paging

Zetron uses a series of tones for its Fire Dispatch & Alerting system.

The tones are outlined in the table below.

Tone #	Grp. 1	Grp. 2	Grp. 3	Grp. 4	Grp. 5
0	1980.0	1177.0	1400.0	832.0	588.0
1	2704.0	1608.0	1912.0	1137.0	804.0
2	2612.0	1553.0	1847.0	1098.0	776.0
3	2523.0	1500.0	1784.0	1061.0	750.0
4	2437.0	1449.0	1723.0	1025.0	725.0
5	2354.0	1400.0	1664.0	990.0	700.0
6	2274.0	1352.0	1608.0	956.0	676.0
7	2196.0	1306.0	1553.0	923.0	653.0
8	2121.0	1261.0	1500.0	892.0	631.0
9	2049.0	1219.0	1449.0	862.0	609.0

SECODE/Digital Dial Alerting

This system is prevalent in the EMS community to "open a line" to hospitals to alert them to incoming patients from ambulance companies. The 2 standard tones used are 2805 & 1500. This system was also used by the older IMTS mobile telephones, prior to cellular.

The system sends a steady tone, and pulses this tone very similar to pulse telephone dialing.

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