VALVE DATA


INTRODUCTION

1. Details of valves used in the receiver are given in Tables 1 and 2
overleaf. The location of valves is shown in fig.8 and valve base
connections are given in the circuit diagram. Voltages were obtained from
a B9A or B7G stand-off valve base using a 20,000 ohms/volt meter on the optimum
range in each case. Valve pin numbers are indicated in brackets in Table 2.

2. The receiver was set as follows:-

(1) SYSTEM switch to MAN.

(2) R.F./I.F. GAIN to MAX.

(3) No signal i.e. first and second v.f.o. off tune.

(4) B.F.O. off except for checking V19.

(5) SYSTEM switch to CAL in order to check V13 and V15 only.




TABLE 1.

Pin 6AK5W 6ES8 6AS6 6BA6 6688 12AT7 6BE6W 6AL5 6AQ5
No. M8100 ECC189 EF93 E180F ECC81 EB91

1 Grid1 Anode2 Grid1 Grid1 Cathode Anode2 Grid1 Cathode1 Grid1
2 Cathode Grid2 Cathode Grid3 Grid1 Grid2 Cathode Anode2 Cathode
& Grid3 & Grid5
3 Heater Cathode2 Heater Heater Cathode Cathode2 Heater Heater Heater
4 Heater Heater Heater Heater Heater Heater Heater Heater Heater
5 Anode Heater Anode Anode Heater Heater Anode Cathode2 Anode
6 Grid2 Anode1 Grid2 Grid2 I.C. Anode1 Grid2 Screen Grid2
& 4
7 Cathode Grid1 Grid3 Cathode Anode Grid1 Grid3 Anode1 Grid1
8 - Cathode1 - - Grid3 Cathode1 - - -
& Screen
9 - Screen - - Grid2 Heater - - -
tap
Base B7G B9A B7G B7G B9A B9A B7G B7G B7G




TABLE 2.

Cct. Type
Ref. Anode Screen Cathode American Equivalent Function

V1 140(5) 75(6) 1.16(2) 6AK5W M8100 Crystal osc./
amplifier
V2 165(5) 120(6) 3.0(2) 6AK5W M8100 Harmonic
generator
V3 172(1) - 1.1(8) 6ES8 ECC189 R.F.amplifier
90(6)
V4 175(5) 120(6) 2.0(2) 6AS6 Harmonic mixer
V5 175(5) 95(6) - 6BA6 EF93 First v.f.o.
V6 196(5) 85(6) 0.95(2) 6BA6 EF93 37.5 Mc/s
amplifier
V7 173(7) 120(9) 0.85(1) 6688 E180F First mixer
V8 195(5) 85(6) 0.95(2) 6BA6 EF93 37.5 Mc/s
amplifier
V9 168(7) 135(9) 0.86(1) 6688 E180F Second mixer
V10 205(5) 108(6) 2.06(2) 6BA6 EF93 37.5 Mc/s
amplifier
V11 155(5) 110(6) 1.95(2) 6AK5W M8100 Second v.f.o.
amplifier
V12 100(6) - - 12AT7 ECC81 Second v.f.o.
195(1) - 44(3)
V13 225(5) 90(6) 2.0(2) 6BE6W Calibrator
V14 175(5) 70(6) 0.92(7) 6BA6 EF93 First i.f.
amplifier
V15 220(5) 110(6) 6.5(7) 6BA6 EF93 Calibrator
V16 180(5) 88(6) 1.46(7) 6BA6 EF93 Second i.f.
amplifier
V17 150(5) 92(6) 1.36(7) 6BA6 EF93 I.F. output
V18 - - 27.0(1) 6AL5 EB91 A.V.C. and
T.C.
V19 155(5) 110(6) - 6AK5W M8100 B.F.O.
V20 -none-
V21 - - - 6AL5 EB91 Detector and
noise limiter
V22 200(5) 198(6) 8.5(2) 6AQ5 Audio output
V23 205(1) - 2.2(3) 12AT7 ECC81 Audio amplifier
104(6) - 1.5(8) and a.f. output
V24 - - - EA.76
V25 165(7) 135(9) 0.72(1) 6688 E180F Third mixer
V26 185(5) 135(6) 0.72(2) 6BE6W Fourth mixer
V27 140(5) 80(6) 1.45(2) 6AK5W M8100 1.7 Mc/s crystal
oscillator/
amplifier


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