User manual ICOM IC-706

[. . . ] AVOID placing the transceiver against walls or putting anything on top of the transceiver. During mobile operation, DO NOT operate the transceiver without running the vehicle's engine. When transceiver power is ON and your vehicle's engine is OFF, the vehicle's battery will soon become exhausted. This will avoid possible damage to the transceiver by ignition voltage spikes. [. . . ] Received audio is not emitted from the speaker while the band scope is "sweeping. " Indicates the relative strength of signals and their location in relation to the center frequency. Signal strength is relative to the S-meter level, S1 to S9, with each vertical dot in the band scope indicator equal to one segment of the S-meter. Signal activity is measured ±30 steps from the center frequency with each step equal to the selected sweep step. After a sweep, indicates the relative position of the selected frequency. When the selected frequency is outside of the sweep range, this indicator flashes. After changing the frequency, push [F3] to automatically return to the center frequency. equal to the selected sweep step. BAND SCOPE INDICATOR FREQUENCY INDICATOR MARK SWEEP STEP 1 ANT USB The band scope measures receive signal conditions over a specified range on either side of a selected frequency in either VFO or memory modes. While menu set 1 is displayed, push [F5](SCP) to S Po ALC SWR 1 3 20 5 7 9 50 20 40 60 100% BLANK select the band scope menu. CH VFOA 1 1. 5 2 3 Rotate the tuning dial to select a frequency. Push [F5](STEP) one or more times to select a sweep step. · During sweep operation " " appears and received signals cannot be heard. · If there is a lot of signal noise, turn the preamp OFF and the attenuator ON to reduce the signal input level and improve the readability of the band scope. P. AMP 1 AGC S SCP F1 STEP 5k F5 When rotating the tuning dial and finding a signal Sweep start/stop Sweep step selection you wish to communicate on, simple communicate normally. · If you want to return to the previous frequency (before rotating the tuning dial), push [F3] for 2 sec. SCP STEP 5k While receiving, if you want to update the band conditions using the selected sweep step, push [F1]. · Each push of [F1] starts and stops the sweep function. Sweep indicator 37 5 FUNCTIONS FOR RECEIVE 5-2 Preamp and attenuator The preamp amplifies received signals in the front end circuit to improve the S/N ratio and sensitivity. The attenuator prevents a desired signal from distorting when very strong signals are near the desired frequency or when very strong electric fields, such as from a broadcasting station, are near your location. See the illustration below. · [TWIN PBT] should normally be set to the center positions when there is no interference. · Not available in FM mode. M1 AGC DUP CMP TCN SCP Twin PBT graphic indication PBT OPERATING EXAMPLE center passband passband IF shift pass band IF center frequency interference desired signal inteference desired signal IF center freq. interference 41 5 FUNCTIONS FOR RECEIVE 5-11 Selecting IF filters Optional filters can be installed in the IF stage of the IC-706 (p. When an optional filter is installed, set the optional filter setting using filter program mode (see below). Filters can be independently selected for each operating mode. FILTER CONSTRUCTION 9 MHz IF filter through FL-272 (2. 4 kHz) (standard) 9 MHz (optional 1) 9 MHz (optional 2) Mixer 455 kHz IF filter CFJ455k (2. 4 kHz) (standard) SFPC455G (9 kHz) (standard) SFPC-455E (15 kHz) (standard) 455 kHz (optional) 3rd LO · 9 MHz optional filters FL-101 (250 Hz) FL-232 (350 Hz) FL-100 (500 Hz) FL-223 (1. 9 kHz) FL-103 (2. 8 kHz) · 455 kHz optional filters FL-53A (250 Hz) FL-52A (500 Hz) FL-222 (1. 8 kHz) FL-96 (2. 8 kHz) FL-257 (3. 3 kHz) NOTE: one 455 kHz optional filter can be installed; two 9 MHz optional filters can be installed. s FILTER PROGRAM MODE SETTINGS Push [FILTER] for 2 sec. to select filter program mode. Push a mode key to select an operating mode for the filter setting. Push [FILTER] to set the filter condition to normal or narrow. · "NAR" appears when narrow is selected. Push [F2](9M) or [F4](455k) one or more times to select a 9 MHz filter or a 455 kHz filter, respectively. Repeat steps to to set filters for other operating modes, if desired. [FILTER] Push [MENU] to return to regular operation. NOTE: See p. 78 for activating the installed optional 9M 455k FIL 2. 4k - 2. 4k F1 F2 F3 F4 F5 filter(s). Selects 9 MHz band filter Selects 455 kHz band filter FIL 9M 455k 2. 4k - 2. 4k 42 FUNCTIONS FOR TRANSMIT 6-1 VOX function 6 The VOX function starts transmission without pushing the transmit switch or PTT switch when you speak into the microphone; then, automatically returns to receive when you stop speaking. Before using this function, follow the steps below. Select a phone mode (SSB, AM, FM). Push [VOX/BK-IN] to turn the VOX function ON and OFF. · "VOX" appears when the function is ON. to select VOX program mode. s ADJUSTING THE VOX GAIN VOX VOX Gain 50% F1 F2 F3 F4 F5 Push [F1] or [F2] to select VOX Gain. While speaking into the microphone, rotate the tuning dial to the point where the transceiver is continuously transmitting. · Be careful that sounds other than your voice are not affecting this setting. Push [MENU] or [VOX/BK-IN] to return to menu set 1. Sets item up/down s ADJUSTING THE ANTI-VOX VOX Anti VOX 50% F1 F2 F3 F4 F5 Push [F1] or [F2] to select Anti VOX. [. . . ] The antenna is not properly tuned. Set the output power to maximum. p. An incorrect transmit frequency is set. Set the proper frequencies into VFO p. 3 Subaudible tone encoder is OFF and repeater requires a tone for access. [COMP GAIN] is rotated too far clockwise with the speech compressor ON. [. . . ]