《RCA-Victor-Co-Inc-54B5 电路原理图.pdf》由会员分享,可在线阅读,更多相关《RCA-Victor-Co-Inc-54B5 电路原理图.pdf(5页珍藏版)》请在收音机爱好者资料库上搜索。
1、MANUAL OF 1948 MOST-OFTEN-NEEDED RADIO DIAGRAMS RCA 54B5 Chassis No. RC1047 Alignment Procedure e C GROUNDING TUBE TO REMOVE STRIPS. SHELF SUB. SPEAKER ASSEMBLY PROM CHASSIS. TO REMOVE LOOP ASSEMBLY 2ND. |.F | Trans, i GANG | CONO. iL _ _ F- TO REMOVE TUBE SHELF SUB ASSEMBLY. TO REMOVE JaC battery B
2、RACKET. * SW. SCREWS H “A 10 REMOVE .CHASSIS i e- T0 REMOVE CHASSIS SUB ASSEMBLY B*l a battery BRACKET Test Oscillator.Connect test oscillator as indicated in chart keeping the output as low as possible to avoid A V C action. Output Meter.Connect a high resistance AC voltmeter in series with a .1 mf
3、d capacitor from top lug of TB1 (plate of 354) to ground. Turn volume control to maximum position. When using the dummy case for theosc. alignment, the loop assembly must he raised slightly so that osc. trimmer becomes accessible. high side of I Tune test-osc. I Turn radio I following for lug of C2,
4、 (located on rear of gang) through a .01 mfd. capacitor *Antenna coupling loop thru 200 ami. capacitor dial to max. peak output Quiet poiat C11.C12 near 1,000 kc 2nd I-P trans. Quiet point C8, C9 near 1,000 kc 1st I-F trans. L2 (osc.) (Rode gang) Repeat steps 4 and 5 for final adjustments. CONNECT T
5、EST OSCILLATOR HERE FOR 1.F ALIGNMENT. CH-C12 L 2N0.I.F 455 Kerr TRANS. (TOP) (BOTTOM C5-OSC, C2-AMT. N0TE. 1600 KC. 4500 KC. A rubher band should be placed around each tuhe for cushioning. Dirty tuhe contacts may he mistaken for a defective tuhe. f-*-MEASURED WITH 1.SV. FTXED BIAS - L.CONV. fiSX -f
6、tSx rL 65 X_, 1 600- 455 KC. 1 4-55 KC | 455 KC. VI V2 IRS 1T4 The IF transformers can he aligned with chassis out of case. Steps 3. 4 and 5 require a coupling loop from the signal generator to feed a signal into the receiver loop located in the back. This loop should he approximately one turn of 6
7、x 3H inches coupled to the signal generator through a 200 mmf. capacitor, and loosely coupled to the receiver loop antenna at about 1H inches distance, so as not to disturb the receiver loop inductance. Ground test oscillator through .1 mf. capacitor to receiver chassis. CRITICAL LEAD DRESS 1. Dress
8、 blue, green and black leads of second IF transformer as direct as possible. If excess lead exists, dress down side of socket and flat against chassis to transformer opening. 2. Cross the green and the black leads Inside the first IF transformer can. keeping the green lead to the outside. Load coil
9、bracket is to separate the blue and the green leads. 3. Dress audio coupling capacitor C14 and the lead to the volume control up and underneath shelf supporting the output transformer. 4. Wire in the three capacitors pyramided hehind the speaker with enough space hehind the battery holder to allow h
10、older to move when battery is replaced. Dress the ground leads of these capacitors to keep from shorting the off-on switch. 5. Observe the outside foil connections on all paper capacitors, also the polarity of the electrolytic capacitor 07. 6. Keep blue and red leads of output transformer above the
11、mounting shelf. 7. Dress all leads as far as possible from loading coil. 8. Dress leads to gang as far as possible from all metal parts. 9. Dress loop leads to keep from interfering with battery replacement; . .BBX_ 455 KC. L, 30 X _ T 400/V V3 155 _ I5X _ 400/v V4 354 APPROX GAIN DATA USING CHANALY5T 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN