RCA-Victor-Co-Inc-110K 电路原理图.pdf

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1、收音机爱 好者资料库 RadioFans.CN MANUAL OF 1941 MOST POPULAR SERVICE DIAGRAMS Push Button The station push buttons connect to separate magnetite-core oscil lator coils and separate antenna trimmers which must be adjusted for the desired stations. Use an insulated screwdriver or alignment tool such as RCA Sto

2、ck No. 31031. Allow at least five minutes warm up period before making adjustments. In the event that the receiver is to be used with an external an tenna use one or two feet of wire (as an antenna) to ensure sharp peaking during the final adjustment procedure. For loop operation, the link should be

3、 strapped across terminals on back of set. In either case the procedure is as follows: 1. Make a list of the desired stations, arranged in order from low to high frequencies. 2. Turn the range selector to “A” band, and manually tune in the first station on the list. 3. Turn range selector to “PB” po

4、sition, push in station button No. 1 (extreme left). Then adjust the No. 1 oscillator core (L-14) to receive the station. Adjustment 4. After oscillator core is set correctly, adjust C-8 for maximum output. Clockwise adjustment of cores and trimmers tunes the circuits to lower frequencies. 5. Adjust

5、 for each of the remaining stations in the same manner. 6. Make a final careful adjustment of the oscillator cores and an tenna trimmers. Owing to the telatively high r-f gain, it may be found that a given station can be tuned m at several different settings of the magnetite-core oscillator push-but

6、ton coils. In such cases, it is advisable to unscrew the loop push-button trimmers to minimum capa city before adjusting the magnetite cores. On the 880 to 1,550 kc push-button, the higher frequency stations may be received with L-9 either in or out (oscillator frequency either 455 kc below or 455 k

7、c above the station frequency). The adjust ment with this core in its out position (oscillator frequency 455 kc above the station frequency) is the correct one. Cathode-Ray Alignment is the preferable method. Connections for the oscillograph are shown in the schematic diagram. Output Meter Alignment

8、.If this method is used, connect the meter across the voice coil, and turn the receiver volume control to maximum. Test-Oscillator.For all alignment operations, connect the low side of the test-oscillator to the receiver chassis, and keep the output as low as possible to avoid a-v-c action. Electron

9、ic Voltmeter.The electronic voltmeter in the Chanalyst or Volt Ohmyst provides an unexcelled output indicator. It should be connected to the AYC bus, and the test-oscillator output adjusted to produce several volts of AVC. Calibration for Alignment.The dial calibration for alignment pur poses can be

10、 set up in two ways: 1. The dial may be removed from the cabinet by sliding out the two spring pieces which clamp it in its mounting position. The condenser plates should then be turned into full mesh, ths pointer adjusted to the scratch at the left end of the dial back ing plate, and the dial place

11、d on the frame so that its extreme left calibration mark coincides with the pointer The dial may be held in place with scotch tape. In this manner the actual receiver dial is used for alignment. When alignment is finished, the scale should be replaced including the fibre light shields which are fold

12、ed under the ends of the glass scale. 2. A calibration scale is attached to the tuning drum. The correct setting of the gang, in degrees, for each alignment frequency is given in the alignment table. Check the position of the drum, making sure that the 0 degree scale mark is horizontal with the gang

13、 in full mesh. Pointer for Calibration Scale. If method (2) is used, improvise a pointer for the calibration scale by fastening a piece of wire to the chassis, and bend the wire so that it points to the 0 degree mark on the calibration scale when the plates are fully meshed. Spread-Band Alignment.Ma

14、ke final adjustment of C56 and C50 during actual reception of a station of known frequency near 9.5 megacycles. 880 TO 19SOKC 6 0 740 TO 149 O KC 4 I *10 TO j i 290 KC I 3 2 I 0 0 940 TO 1090 KC 1 TRIMMER (?) SCREWS _ e l _ 6 1 5 136 RODS Steps Connect the high side of the test-osc. to Tune test osc

15、. to Turn radio dial to Adjust the follow ing for maximum peak output 1 I-F grid in series with .01 mfd. 455 kc “C” Band Quiet Point at 18 me end of dial L21 and L22 (2nd I.F. Trans.) 2 lst-det. grid in series with .01 mfd. L19 and L20 (1st I.F. Trans.) 3 Antenna terminal (A), in series with 47 mmfd

16、. (link closed) 15.2 me 15.2 me (149) C” band C56 (osc.)* C50 (ant.)* Rock in 4 9.5 me 9.5 me (65.5) “31MM band C55 (osc.)* C51 (ant.)* Rock in 5 Stator of antenna section of gang, in series with 300 ohms 2.44 me 2.44 me (97) “B* band C27 (osc.) 6 600 kc 600 kc (30.5) “A” band L28 (osc.) 7 1,500 kc

17、1,500 kc (158) “A band C28 (osc.) 8 Repeat steps 6 and 7. 9 Fasten chassis in cabinet, see that link is closed on antenna terminal board, indicator at left end of dial scales with gang at maximum capacity. 10 Radiation loop consisting of two turns of wire 18 inches in dia meter located 4 to 6 feet f

18、rom receiver 1,500 kc 1,500 kc “Av band C61 (ant.) (mounted on loop) 11 600 kc 600 kc “A” band L28 (osc.) Rock in 12 Repeat steps 10 and 11 * Use minimum capacity peak if two peaks can be obtained. * Use maximum capacity peak if two peaks can be obtained. NOTE: Oscillator tracks 455 kc above signal on all bands. MODEL 110-K COMPILED BY M. N. BEITMAN, SUPREME PUBLICATIONS 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN