Checking And Adjusting The Band-Pass Curve Of The Ratio Detector Of An F.m. Receiver - Philips PM5324 Instruction Manual

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2.3.3.2. Checking and adjusting the band-pass curve of f.m. receivers
R6
10k
Fig. 12. Checking and adjusting the band-pass cur ve of the ratio detector of an f.m. recei ver
Fig. 13. Checking and adjusting the band-pass cur ve of the IF band filter of an f.m. recei ver
2.3.3.2. 1 . I F band-pass filters
- Set t h e volume control to minimum
- Set the tuning at the long wave end
- Set the receiver to f.m.
- Screw out the cores of the i.f. band-pass filters as far as possib l e; if necessary note the tri m ming table
- Con nect h.f. generator
receiver via the dum m y aerial
- Adjust h.f. generator PM 5324 to t h e i.f. frequency
- Connect the indicator according to Fig. 14
- Adjust the core of the primary circuit (Fig. 14) of the ratio d etector to m aximum defl ection of the indicator
- Terminate the prim ary circuit of t h e ratio detector with a resistor of approx. 10 kD (R6, Fig. 12). Adjust the
core of the secondary circuit to min imum deflection of the indicator, which is connected according to Fig. 12.
Repeat t h e adjustment.
- Adjust the cores of t h e other i.f. band-pass fi lters in t h e sequence indicated in the service documentation o f
the receiver.
The circuits of a band-pass filter which are not adjusted should be terminated with a resistor of approx. 10 kD
duri ng the adjustment of a circuit o f t h e band·pass filter (Fig. 14).
Rl
T
PM 5324 to the connection point indicated i n the service d ocum entation of
Indtcator
(e.g. PM
(R'=R�)
R 2
Indicator
2403)
(e.g. PM
3V",
MA9210
24031
3 V '"
MA8209
t h e