Heathkit IM 28U Schematic

Page 1

41

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NOTES 3;" R3 R10
2" ' 22M

ALL RESISTANCES IN OHMS K x 1000,
HES = 1,000,000.

ALL RESISIGRS I/z MATT UNLESS arugu-
HISE SPECIFIED. VI
ALL CAPACITORS IN 11? UNLESS omER- 6 ALS

RANGE SWITCH
WAFER A' FRONT

\I

RISE SPECIFIED.
ALL VOLTAGES MEASURED WITH RESPECT
TO CHASSIS GROUND. '

ALL vomcss posmve IIIILEss eman-
uISE SPECIFIED.
VOLTAGES TAKEN mm AN 11 MEGOHM
WM.
ALL suncuEs 1:1:qu mu THE REAR. C _
RANGE suncn 1N MXIMUH COUNTER- -°7 .-
CLOCKHISE POSITION. .
runcnou sync" 1N Ac POSITION.
FIGURES gmsto mus; C)
ARE cormscnous
10 cracun BOARD.

//- Fuucnou svn'rcu /
WAFER A' RSAR /
/ FUNCTION smrcw
/ WAFER'SREAR '
/ FUNCTDN swncu
/ mrsaxmom A
/3 /
O l'\ '
/
/

oc PROBE 2 mo";
(-5? / ' JACK

..

| ..__
L_RI 71/ '!

1'." Ri6 RI? RIB RIO

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R20 :12: 922 A

6.1!! 2J6?

RANGE SWITCH
HAFER C REAR

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SCHEMATIC or THE !
HEATHKIT }
VALVE VOLTMETER 1
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FUNCTION swarm-c
WAF ER 'c' REAR

MODEL IM'~28U
115

I00 250
Fused Voltage 25 N
O

/RANGE MTG

Gauss swncn .
/ mnaa as

/ urea 3' mom-

/ / 9.: Soleuor Plug
/ / +1 aaI R32 R33 ' 334
am- ._... 1/. R35 R36 R37
// / If '"F / 0' @" (@0135 $1.31; $35
A u
___ __/ _ / -.- _/ 66)" ®
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