User manual FURUNO 42A12D OPERATORS MANUAL

[. . . ] Auxiliary Connections and Uses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Audio Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] The test set AUDIO OUTPUT jack circuit is designed to work into a load impedance of approximately 10 ohms which is ideal for attachment of low impedance head phones. Operation into higher impedance such as oscilloscopes, meters, chart recorders or other types of readout equipment is permissible. No DC potential is present on the AUDIO OUTPUT jack. CAUTION A SHORT ACROSS THE AUDIO OUTPUT JACK MAY CAUSE DAMAGE TO THE TEST SET CIRCUITRY. CAUTION TEST SET IS NOT WATER-PROOF OR SPLASH PROOF. SOME FORM OF PROTECTION SHOULD BE PRO-VIDED WHERE SPLASH CONDITIONS EXIST. 03-TM-0038 REV 00 PAGE 2 OF 5 SECTION II OPERATION 2. 1. Turn the GAIN control to a fully clockwise position. A pronounced background noise should be present. Lack of noise may indicate a dead battery. Should this occur, replace battery before resuming operational testing. Set the TUNING control to approximately midscale. Rubbing fingers in front of microphone should produce a rushing noise from speaker. Actuate a beacon under test by immersing the water switch in tap water, or by shorting the water switch terminal to the case by means of a shorting tab. The beacon need not be removed from its mount on the aircraft to perform operational testing. Set the GAIN control at a comfortable listening level. Point the microphone of the Test Set towards the water switch end of the Beacon for best results. If the Beacon is mounted, position the Test Set for maximum unobstructed signal. Beacon operation will be indicated by an audible pulsing tone. The tuning control permits reception of an acoustic signal operating anywhere within the 30 to 45 kHz frequency range. The audio response is peaked at about 3200 Hz; therefore, the test set should be tuned to produce an output signal of approximately this frequency to achieve greatest sensitivity. CAUTION TO CONSERVE BATTERY LIFE, GAIN CONTROL SHOULD BE SET TO OFF POSITION WHEN TEST SET IS NOT IN ACTUAL USE. 03-TM-0038 REV 00 PAGE 3 of 5 SECTION III MAINTENANCE 3. 1. BATTERY LIFE With intermittent usage, battery operating life will be approximately 30 to 40 hours depending on the type of and manufacturer of the battery. [. . . ] Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . NEDA Type 1604A B T1 R 13 10K S1 W S P WR W OE L1 2. 02 C 13 68 R 20 10 R 31 R 32 10 10 LS 1 SEKR PAE D 3 1N 4454 D 4 1N 4454 R 24 2. 6K 1 1U 2D 14 LF444 4 C 18 68 9V C 1 68 R 1 33. 1K R 6 221K Q 3 2N 5086 R 8 100K C 10 68 D 2 1N 4005 T1 Y 1 TR N U E A SD C R D 1 1N 4005 1408 Q 2 2N 5088 Q 1 2N 5088 R 3 3. [. . . ]