SQL | Squelch or Threshold Level knob. Sets the threshold level for the minimum |
| receiver signal. |
| Turn fully |
| clockwise (right) until the random noise disappears. Make another ¼ turn clockwise |
| for best reception in open sea conditions. |
| In areas of high noise (eg close to large cities) reception may improve if sensitivity is |
| reduced by turning SQL slowly clockwise (right). Also see REJ (noise rejection) and |
| LOC (Local mode) because these may also improve reception quality. |
88/9 | Priority Channel (Australia). Also on the microphone. Press to cancel all other |
| modes and tune into the priority channel (CH88 if MB is selected, or CH9 if CB |
| is selected). See Section 2.3.6 for an example. Press 88/9 again to return to your |
| original channel. |
| In countries other than Australia, consult your dealer about your local priority |
| channels. |
BAND | Channel Band. Press to toggle between marine (MB) and land (CB) channel band |
| frequencies. The screen shows the selected channel band and radio tunes to the |
| most recently used channel in that channel band. See Section 2.3.2 for an example. |
| Appendix C shows the frequencies for each channel band. |
3CH | Three Favourite Channels. Also on the microphone. You can store three favourite |
| channels for marine (MB) and another three favourites for land (CB) channel band |
| frequencies. |
| To store a favourite channel for the first time, select the channel band, then the |
| channel. Press and hold 3CH for at least 1.5 seconds to store it in the CH1 location. |
| Repeat the procedure to store two more favourite channels in the CH2 and CH3 |
| locations respectively. See Section 2.3.9 for an example. |
| NOTE: If you try and add another favourite channel with 3 already stored,“FL” |
| shows in the display. You may store a new CH3 frequency only after deleting |
| the old one. CH1 and CH2 remain unless you delete them. |
| To select a favourite channel, select the channel band then press 3CH to toggle |
| between your favourite channels. The channel band and CH1, CH2, or CH3 are |
| displayed to show which favourite channel is currently selected. |
| To delete a favourite channel, select it then press and hold 3CH for at least 1.5 |
| seconds until the CH1, CH2 or CH3 symbol disppears off the screen. |
DIM | Backlighting. Press repeatedly to step through the settings (OFF, LOW, MED, HIGH) |
| until the desired backlight level is obtained. |
SCAN | Scanning Mode. PSCAN and ALL SCAN modes are available on both land (CB) and |
| marine (MB) channel bands. |
| To scan one channel, select that channel then immediately press and release SCAN. |
| The radio goes into PSCAN mode; scanning the selected channel and automatically |
| checking the priority channel once every 4 seconds (like Dual Watch mode). |
| To scan one favourite channel, select that channel with 3CH then immediately |
| press and release SCAN. The radio goes into PSCAN mode; scanning the favourite |
| channel and automatically checking the priority channel once every 4 seconds |
| (like Dual Watch mode). See section 2.3.11 for an example. |
8 | NAVMAN MCB 7270 Marine CB 27 MHz Radio Operation Manual |