Tektronix DC 501 Instruction Manual page 25

Electrical Parts
List—
DC
501
COUNTER TIME BASE AND CONTROL
(cont)
Ckt
Grid
Tektronix Serial/Model No.
No.
Loc
Port
No.
Eff
Disc
Description
INTEGRATED CIRCUITS (cont)
U213
F3
156-0079-00
single
10
MHs divlde-by-2-&-5 ripple counter,
replaceable by SN7490N
U21A G3
156-0079-00 Single
10
MHz dlvlde-by-2-&-5 ripple counter,
replaceable by SN7490N
U215 H3
156-0079-00 Single
10
MHz dlvide-by-2-&-5 ripple counter,
replaceable by SN7490N
U220 K2
156-0042-00
Dual IS
MHz J-K Daster-slave flip-flop, replaceable
by SN7476N
U222 L2
156-0174-00
Dual 20
MHz J-K aaater-slave
flip-flop, replaceable
by SN74111N
U230 J2
156-0150-00
Quad 2-lnput positive nand buffer, replaceable by
SN7437N
CRYSTALS
Y200, F5
158-0079-00
Crystal,
1
MHz
Y201
F6
119-0262-00 Oscillator,
RF,
5
MHz
Option 1
only.
3-8