a1 fil + to tube pin 1 b1 fil + to tube pin 2 c1 fil + to tube pin 3 d1 fil + to tube pin 4 e1 fil + to tube pin 5 f1 fil + to tube pin 6 g1 fil + to tube pin 7 h1 fil + to tube pin 8 j1 fil + to tube pin 9 k1 use DC filament supply l1 aux bus to aux B+ a2 fil - to tube pin 1 b2 fil - to tube pin 2 c2 fil - to tube pin 3 d2 fil - to tube pin 4 e2 fil - to tube pin 5 f2 fil - to tube pin 6 g2 fil - to tube pin 7 h2 fil - to tube pin 8 j2 fil - to tube pin 9 k2 use DC filament supply l2 210 - 170 reg B+ range a3 control grid line to tube pin 1 b3 control grid line to tube pin 2 c3 control grid line to tube pin 3 d3 control grid line to tube pin 4 e3 control grid line to tube pin 5 f3 control grid line to tube pin 6 g3 control grid line to tube pin 7 h3 control grid line to tube pin 8 j3 control grid line to tube pin 9 k3 control grid line to tube cap l3 subtract 20 v from reg B+ (use with l4) a4 cathode line to tube pin 1 b4 cathode line to tube pin 2 c4 cathode line to tube pin 3 d4 cathode line to tube pin 4 e4 cathode line to tube pin 5 f4 cathode line to tube pin 6 g4 cathode line to tube pin 7 h4 cathode line to tube pin 8 j4 cathode line to tube pin 9 k4 cathode line to tube cap l4 subtract 20 v from reg B+ a5 screen line to tube pin 1 b5 screen line to tube pin 2 c5 screen line to tube pin 3 d5 screen line to tube pin 4 e5 screen line to tube pin 5 f5 screen line to tube pin 6 g5 screen line to tube pin 7 h5 screen line to tube pin 8 j5 screen line to tube pin 9 k5 open for aux B+ supply, screen Gm/bridge/B+ l5 tube screen to AUX B+ a6 suppressor line to tube pin 1 b6 suppressor line to tube pin 2 c6 suppressor line to tube pin 3 d6 suppressor line to tube pin 4 e6 suppressor line to tube pin 5 f6 suppressor line to tube pin 6 g6 suppressor line to tube pin 7 h6 suppressor line to tube pin 8 j6 suppressor line to tube pin 9 k6 suppressor line to tube cap l6 to positive bias supply a7 plate line to tube pin 1 b7 plate line to tube pin 2 c7 plate line to tube pin 3 d7 plate line to tube pin 4 e7 plate line to tube pin 5 f7 plate line to tube pin 6 g7 plate line to tube pin 7 h7 plate line to tube pin 8 j7 plate line to tube pin 9 k7 plate line to tube cap l7 meter shunt current range a8 aux bus to tube pin 1 b8 aux bus to tube pin 2 c8 aux bus to tube pin 3 d8 aux bus to tube pin 4 e8 aux bus to tube pin 5 f8 aux bus to tube pin 6 g8 aux bus to tube pin 7 h8 aux bus to tube pin 8 j8 light DUAL TEST lamp k8 aux bus to aux cathode l8 aux bus to 0 volts a9 filament 0V b9 filament 10V c9 filament 20V d9 filament 30V e9 filament 40V f9 filament 50V g9 filament 60V h9 filament 70V j9 filament 80V k9 filament 90V l9 filament 100V a10 filament 0V b10 filament 1V c10 filament 2V d10 filament 3V e10 filament 4V f10 filament 5V g10 filament 6V h10 filament 7V j10 filament 8V k10 filament 9V l10 filament 110V a11 filament 0V b11 filament .1V c11 filament .2V d11 filament .3V e11 filament .4V f11 filament .5V g11 filament .6V h11 filament .7V j11 filament .8V k11 filament .9V l11 center-tapped fil resis to cathode supply a12 use AC filament supply b12 filament to DC rect thru choke (unused) c12 res A Choice No. 1280 d12 res B Choice No. 640 e12 res C Choice No. 320 f12 res D Choice No. 160 g12 res E Choice No. 80 h12 res F Choice No. 40 j12 res G Choice No. 20 k12 res H Choice No. 10 l12 meter shunt current range a13 plate quality supply / bridge b13 plate quality supply / bridge c13 plate quality supply / bridge d13 10 ohm R e13 100 ohm R f13 1000 ohm R g13 10k ohm R h13 plate quality supply Gm bridge j13 plate quality supply to 0V k13 grid supply to cathode w .222v l13 grid supply to catode w/o .222v a14 leakage test shunt, +20 microamperes b14 leakage test shunt, +50 microamperes c14 leakage test shunt, +100 microamperes d14 20 ohm R e14 200 ohm R f14 2000 ohm R g14 20k ohm R h14 cathode supply to unreg B+ j14 4 mf cap across load res k14 self-bias mode l14 cathode supply to 0V a15 Gm bridge to 0V b15 use AC filament supply c15 Gm bridge to 0V d15 30 ohm R e15 300 ohm R f15 3000 ohm R g15 30k ohm R h15 plate current test from reg B+ j15 reg B+ to screen line k15 plate current test from reg B+ l15 screen supply to 250 VAC a16 self-bias resistor b16 divider c16 divider d16 40 ohm R e16 400 ohm R f16 4000 ohm R g16 cathode supply to unreg B+ h16 supp. line biased as control grid w/o signal j16 supp. supply to Bias Off (high neg bias) k16 supp. to 0v floating ground reference l16 supp. line tied to cathode a17 NC b17 160 - 120 reg B+ range c17 110 - 60 reg B+ range d17 50 - 10 reg B+ range e17 subtract 10 v from reg B+ f17 plate quality supply / bridge g17 disable leakage test lamp h17 NC j17 plate line to meter for DC current measurements k17 plate line to top of Gm bridge l17 plate line to 500 VAC for recifier tests