User manual MIDLAND 79-290

[. . . ] TABLE OF CONTENTS Specifications Installation Location Mounting the Radio Ignition Noise Interference Antenna Tuning the Antenna for Optimum SWR External Speaker Operation Control and Indicators Front Panel Real Panel Operating Procedure to Receive Operating Procedure to Transmit Receiving SSB signals SPECIFICATIONS (CB) GENERAL Channels Frequency Range Frequency Control Frequency Tolerance Frequency Stability 40 CH/AM//USB/LSB (120 ch. total) 26. 965 + 27. 405 CB Phase Lock Loop (PLL) synthesizer 0. 005% 0. 001% Operating Temperature Range Microphone Input Voltage -20° C to + 50° C Plug-in dynamic; with push-to-talk switch 13. 8 V DC nominal, 15. 9 max. , 11. 2 V min ( negative ground) and coi 2 TRANSMITTER Power Output AM 4 Watts SSB 12 Watts PEP AM/SSB SSB 3rd order, more than -25 dB 5th order, more than -35 dB 55 dB 50 dB AM 350 to 2500 Hz Modulation Intermodulation Distortion SSB Carrier Suppression Unwanted Sideband Frequency Response RECEIVER Sensitivity . 50 uv AM . 25 uv SSB AM/FM: 10. 695 MHz 1st IF, 455 kHZ 2nd SSB: 10. 695 MHz IF Frequency IF Adjacent-Channel Rejection Automatic Gain Control (AGC) Squelch Adjustable; 60 dB AM/SSB Less than 10 dB change in audio output for inputs from 10 to 100. 000 microvolts threshold <. 50 uv tight 1000 uv 4 watts into 8 ohms Audio Output Power WEATHER RECEIVER Channels 1 162. 550 5 162. 450 8 161. 550 2 162. 400 6 162. 500 9 161. 775 3 162. 475 7 162. 525 10 163. 275 4 162. 425 *All specifications subject to change without notice 3 Your new Midland model 79-290 represents cutting edge technology in the communications field. From its high tech detachable control panel to finned cast almuinum transmitter heatsink it incorporates features found on no other CB. These features include full surface mount technoloy, fiberglass printed circuit board, dual power output stage, and a digital information screen using a black matrix LCD (liquid crystal display). [. . . ] Turn fully counterclock-wise then slowly clockwise until the receiver noise disappears (wtih car engine running). Any signal to be received must now be slightly stronger than the average received noise. Further clockwise rotation will increase the threshold level which a signal must overcome in order to be heard. When the MIC symbol is visible in the LCD screen it indicates a reduced microphone power level. To be used to reduce the gain of the RF amplifier under strong signal conditions. When the "LOC" indicator is visible in the LCD screen the receiver is in the local mode (short range). Normally the unit would be operated in the distant mode (long range) with the "LOC" disabled. The channel or frequency display flashes channel 19 when instant channel 19 is selected. The rotary channel selector is bypassed when the CH19 button is activated. Press the CH 19 button again to return to normal channel selection. 7 6. Press this button for instant selection of the NOAA weather bureau or Canadian receiver. Select the proper channel, with the rotary channel selector, for your area. It is normal to hear the same information on more than one channel, select the channel with best sound. This indicator on the LCD screen will be illuminated when the unit has been set in TX mode. This switch selects any one of the forty Citizens Band channels desired. The channel selector is bypassed and will not operate when instant channel 9 or 19 has been selected. To set channels in the memory , select the desired channel for M1, press and hold the "M1" button until a second beep is heard and the memory channel indicator lights. Unless the station with which communication is desired is equipped with SSB, the AM mode is normally used. The band "BD" button changes the mode of operation of both transmitter and receiver simultaneously. Turn to `'Receiving SSB signals'' for a further explanation of single sideband. Continued pressing of the band button causes the unit to keep switching between AM/LSB/USB as indicated by the LCD screen. This control allows variation of the receiver operating frequencies above and below the assigned frequency. [. . . ] Also, SSB takes only half of an AM channel, therefore two SSB conversations will fit into each channel, expanding the 40 AM channels to 80 SSB channels. The reduction in channel space required also helps in the receiver because only half of the noise and interference can be received with 100% of the SSB signal. 11 An SSB signal may be received only when the listening receiver is functioning in the same mode. In other words, an upper sideband signal (USB) may be made intelligible only if the receiver is functioning in the USB position. If a lower sideband (LSB) signal is heard when the receiver is in the USB mode, no amount of tuning will make the signal intelligible. The reason for this may be understood if you consider that when modulation is applied to the transmitter's microphone in the USB mode, the transmitter's output frequency is increased whereas in the LSB mode the transmitter's output frequency is decreased. [. . . ]