148.GTL.ST.MANUAL 10/1/98 10:56 AM Page 13
Section IV Operation (Continued)
4.SWR CAL CONTROL (outer concentric dial). In order for you to achieve maximum radiated power and the longest range, it is important that your antenna be in good condition, properly adjusted and matched to your trans- ceiver. The
5.DYNAMIKE. Adjusts the microphone gain in the transmit and PA modes. This controls the gain to the extent that full talk power is available several inches away from the microphone. In the Public Address (PA) mode the control functions as the volume control.
6.VOICELOCK. Allows variation of the receiver operating frequencies above and below the assigned frequency. Although this control is intended primarily to tune in SSB signals, it may also be used to optimize AM signals as described in the Operating Procedure paragraphs.
7.DIM/NOR/BRT SWITCH. Controls the brightness of the meter and LED chan- nel indicator for optimum intensity for day or
8.CHANNEL SELECTOR. This switch selects any one of the forty Citizens Band or 80 single side band channels desired. The selected channel appears on the LED readout directly above the Channel Selector knob. Channel 9 has been reserved by the FCC for emergency communications involving the immediate safety of life of individuals or immediate protection of property. Channel 9 may also be used to render assistance to a motorist.
9.
Section IV Operation (Continued)
10.PA/CB SWITCH. Selects the mode of operation. In the CB position, the PA func- tion is disabled and the unit will transmit and receive on the speaker that is con- nected. In the PA mode, incoming CB transmission will be heard through the PA speaker. This allows you to monitor messages while outside of your vehicle.
To use the PA feature, a speaker having a voice coil impedance of 8 ohms and a power handling capability of at least three watts should be used. This speak- er must be plugged into the PA SPKR jack at the rear of the transceiver. If the public address feature is to be used primarily for outdoor applications, the use of a weatherproof horn type public address speaker is recommended. The durability of this type speaker plus the inherent efficiency of such a speaker will provide more than adequate results when combined with the high audio output level available from the COBRA 148 GTL ST. With the PA speaker con- nected as outlined previously, be sure that there is physical separation between the microphone and the speaker itself. If the speaker is located too close to the microphone, acoustic feedback will result when the public address system is operated at high volume. A directional type outdoor speaker reduces the amount of isolation required. Some experimentation will deter- mine the minimum amount of isolation required for a given sound level from the public address system.
NOTE
PA volume is controlled by adjusting the DYNAMIKE knob to the desired volume.
11.
When in the “CAL” position, the SWR meter can be calibrated by adjusting the “SWR” control to the “CAL” mark on the meter face.
When in “SWR” position, the standing wave ratio is measured.
12.MODE (USB/AM/LSB) SWITCH. This switch is used to select AM, LSB or USB mode of operation. Unless the station with which communication is desired is equipped with SSB, the AM mode is normally used. The mode selector switch changes the mode of operation of both transmitter and receiver simultaneous- ly. Turn to “Receiving SSB signals” for a further explanation of single sideband.
13.TONE SWITCH HI/NOR/LOW. This switch is used to shape the audio response to the operator’s preference. Bass is increased in the LOW position and treble is increased in the HI position.
14.SOUNDTRACKER™ SWITCH. Depressing this button turns on the SoundTracker system in your CB.
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