CTCSS/DCS/EPCS Operation, Ctcss Operation

CTCSS/DCS/EPCS OPERATION

CTCSS OPERATION

Many repeater systems require that a very-low-frequency audio tone be superimposed on your FM carrier in order to activate the repeater. This helps prevent false activation of the repeater by radar or spurious signals from other transmitters. This tone system, called “CTCSS” (Continuous Tone Coded Squelch System), is included in your VX-177, and is very easy to activate.

CTCSS setup involves two actions: setting the Tone Mode and then setting of the Tone Frequency. These actions are set up by using the [1(SQ TYP)] key and [2(CODE)] keys.

1.Press the [F] key, then press the [1(SQ TYP)] key to enable selection of the CTCSS/ DCS/ECS mode.

2.Rotate the DIAL knob so that “TONE” indication appears on the

display; this activates the CTCSS Encoder, for access to repeat- ers requiring a CTCSS tone.

3. Rotation of the DIAL knob one more “click” in step “2” above

will cause the “TSQL” notation to appear. When “TSQL” is dis- played, this means that the Tone SQueLch system is active, which mutes your VX-177’s receiver until it receives a call from an-

other radio sending out a matching CTCSS tone. This can help keep your radio quiet until a specific call is received, which may be helpful while operating in congested areas of the band.

1)You may notice a “REV TN” indication on the display while you rotate the DIAL knob in this step; this means that the Reverse Tone Squelch system is active, which mutes your VX-177’s receiver (instead of opening

the squelch) when it receives a call from the radio sending a matched CTCSS tone. The “” icon will blink on the display when the Reverse Tone Squelch system is activated.

2) You may notice the “DCS” and “ECS” indications on the display while you rotate the DIAL knob still more. We’ll discuss the Digital Code Squelch system (for “DCS”) and Enhanced Paging & Code Squelch (for “ECS”) later.

4.When you have made your selection of the CTCSS tone mode, press the PTT switch

to save the new setting.

5.Press the [F] key, then press the [2(CODE)] key to

enable adjustment of the CTCSS fre- quency.

6.Rotate the DIAL knob until the display indicates the Tone Frequency you need to

CTCSS TONE FREQUENCY (Hz)

67.0	69.3	71.9	74.4	77.0	79.7
82.5	85.4	88.5	91.5	94.8	97.4
100.0	103.5	107.2	110.9	114.8	118.8
123.0	127.3	131.8	136.5	141.3	146.2
151.4	156.7	159.8	162.2	165.5	167.9
171.3	173.8	177.3	179.9	183.5	186.2
189.9	192.8	196.6	199.5	203.5	206.5
210.7	218.1	225.7	229.1	233.6	241.8
250.3	254.1	–	–	–	–

VX-177 OPERATING MANUAL