Dismantling - Racal Instruments RA-117 User Manual

15. Dismantling

Unit Breakdown
1. The receiver may be rapidly dismantled to eight sub-units as follows:-
(1) Front Panel
(a) Tuning escutcheon.
(b) Loudspeaker and escutcheon.
(c) Output level meter.
(2) Second Variable Frequency Oscillator
(a) Second v.f.o. (V12).
(3) First Variable Frequency Oscillator
(a) R.F. Amplifier (V3).
(b) First v.f.o. (V5).
(c) First Mixer (V7).
(4) 100 kc/s I.F. Amplifier
(a) Beat frequency oscillator (V19).
(b) Crystal Filter.
(c) L-C filter.
(d) First and second I.F. amplifiers (V14 and V16)
(e) A.V.C. and T.C. stages (V18)
(f) Detector and noise limiter (V21)
(g) 100 kc/s output (V17)
(5) Crystal Calibrator (V13 and V15)
(6) Main Chassis
(a) Aerial (antenna) attenuator.
(b) Crystal oscillator amplifier (V1).
(c) Harmonic generator (V2).
(d) 30 and 32 Mc/s low-pass filters.
(e) 37.5 and 40 Mc/s band-pass filters.
(f) Harmonic mixer (V4).
(g) The 37.5 Mc/s amplifiers (V6), (V8) and (V10).
(h) Second mixer (V9).
(i) A.F. output stages (V22) and (V23).
(7) 1.7 Mc/s oscillator/amplifier and mixer unit
(a) Second v.f.o. amplifier (V11).
(b) Third mixer (V25).
(c) Fourth mixer (V26).
(d) 1.7 Mc/s oscillator/amplifier (V27)
(8) 2 – 3 Mc/s Band-pass Filter
Dismantling and Re-Assembly Instructions
2. Front Panel
(1) Remove all control knobs.
(2) Unscrew the eight instrument head panel fixing screws.
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