Continuous or Burst SUBTONES?, Freq | Kenwood TS-570D, TS-570S

7 SPECIALIZED COMMUNICATING

SELECTING SUBTONE FREQUENCY

FM CTCSS OPERATION

Some 10-meter FM repeaters require the transceiver to transmit a subtone, to prevent other repeaters on the same frequency from locking each other up. The required subtone frequency depends on the repeater you are accessing. In Europe, a 1750 Hz tone is generally used to access repeaters.

Select the subtone frequency you require via Menu No. 18. The default is 88.5 Hz. The available choices are shown in the table below.

No.	Freq.	No.	Freq.	No.	Freq.	No.	Freq.
No.	(Hz)	No.	(Hz)	No.	(Hz)	No.	(Hz)
01	67.0	11	97.4	21	136.5	31	192.8
02	71.9	12	100.0	22	141.3	32	203.5
03	74.4	13	103.5	23	146.2	33	210.7
04	77.0	14	107.2	24	151.4	34	218.1
05	79.7	15	110.9	25	156.7	35	225.7
06	82.5	16	114.8	26	162.2	36	233.6
07	85.4	17	118.8	27	167.9	37	241.8
08	88.5	18	123.0	28	173.8	38	250.3
09	91.5	19	127.3	29	179.9	39	1750
10	94.8	20	131.8	30	186.2

Note: Use Nos. 01 to 39 shown in the table above when selecting subtone frequencies via Computer Control {page 51}.

CTCSS is the abbreviation for Continuous Tone Coded Squelch System. CTCSS uses subaudible tone frequencies. While you are transmitting, a subtone that you select is superimposed on your transmit signal.

Suppose that only stations “A”, “B”, and “C” are programmed with the same subtone frequency. When “A” calls, the squelch on only “B” and “C” opens. So you can choose which stations will receive your transmissions.

1Press [A/B] to select VFO A or VFO B.

•“tA” or “tB” appears to show which VFO is selected.

2Select the desired subtone frequency via Menu No. 18.

3Select the operating frequency.

4Press [FM/AM] to select FM mode.

•“FM” appears.

5Turn the SQL control to adjust squelch.

6Repeatedly press [AGC/TONE] until “CTCSS” appears.

CONTINUOUS OR BURST SUBTONES?

In addition to selecting the frequency of the subtone, you must choose the correct subtone duration. The Continuous selection continuously sends the subtone as long as the transceiver is transmitting. The Burst selection sends a 500 ms subtone burst each time the transceiver begins transmitting.

Select either Continuous or Burst via Menu No. 19. The default is Continuous except on some European versions.

•To quit CTCSS, press [AGC/TONE] again.

7When you are called:

The squelch in your transceiver opens only when the selected subtone is received.

When you make a call:

Press and hold Mic [PTT], or press [SEND].

•The selected subtone is superimposed on your transmitted signal.

Note:

◆When using split-frequency operation, select FM mode on both VFOs to use CTCSS.

◆While selecting 1750 Hz subtone, you cannot switch ON the

CTCSS.

◆Input to the microphone is muted while transmitting a 1750 Hz subtone.