TONE CODED SQUELCH
Yaesu FT-8900R Operating Manual Expanded Edition (courtesy of W5JCK) Page 27 of 77
Tone Coded Squelch
CTCSS Tone System
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 FT−8900R, 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 Set mode Menu #40 TONE M and Menu #39
TONE F.
1. Press the SET key momentarily to enter the Set mode.
2. Rotate the DIAL knob to select Menu #40 TONE M.
3. Press the DIAL knob momentarily, then rotate the DIAL knob so that ENC
appears on the display; this activates the CTCSS Encoder, which allows repeater
access.
You may notice an additional icon appearing while you rotate the
DIAL knob in this step. (See DCS Tone System on page 28.)
4. Rotating the DIAL knob one more click clockwise in step 3 above will cause
ENC.DEC to appear. When ENC.DEC appears, this means that the Tone Squelch system
is active, which mutes your FT−8900R’s receiver until it receives a call from another
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.
5. When you have made your selection of the CTCSS tone mode, press the DIAL
knob momentarily, then rotate the DIAL knob one click counterclockwise to
select Menu #39 TONE F. This Menu selection allows setting of the CTCSS tone
frequency to be used.
6. Press the DIAL knob momentarily to enable adjustment of the CTCSS frequency.