GENERAL RADIO COMPANY 1650-B Instruction Manual page 14

OPERATING INSTRUCTIONS
MULT
R A R
H
1 I0 100.
10k lOOk 1M
MULT
RAR
nU
100
1M
HIGH
o
(I
m)
0
R'-
" LX u R T C T
a. Turn GENERATOR switch t o
B A T CHECK.
If
the meter pointer
isn't i n the B A T sector, replace
the batteries.
b .
Turn GENERATOR switch t o AC
E X T E R N A L or AC INTERNAL
1 kHz.
c. Turn PARAMETER switch t o
Lp.
d.
Connect unknown so that most
stray capacitance i s between the
LOW terminal and the 1650-B case.
e. Turn ORTHONULL@ switch t o
OUT.
f.
Turn OSC L E V E L clockwise.
The panel control affects only the
internal oscil[ator. Use f u l l output
except for nonlinear unknowns.
I r o n core inductors are often non-
I
near.
'
g. Turn DQ d i a l near
5
on the HIGH
Q scale.
h.
Turn CGRL d i a l near 11.
i.
Adiust D E T SENS for about
6
divisions deflection.
i.
Turn M U L T I P L I E R switch for
minimum meter reading.
k.
Alternately adiust the CGRL and
DQ dials for the best null, CGRL
first, increasing the D E T SENS as
needed. N u l l means bring the
pointer as near t o the center of the
meter as possible. Usually i t won't
be possible to center the pointer.
I. ORTHONULL@
i s not used on
t h i s bridge unless the DQ d i a l
reading times l / f (kHz) approaches
1 or less.
m. If a sharp nu1
l
cannot be ob-
tained, the unknown i s too lossy
and must be measured as
Ls,
or
the unknown i s not inductive.
n .
The ~ a r a l l e l inductance of the
unknown equals the product of the
CGRL-dial reading and the MULTI-
PLIER-switch setting.
o.
The Q of the unknown equals the
d i a l reading times l / f (kHz).
p. Turn GENERATOR switch t o
OFF.
G
RESISTANCE c l n
m
1 o o o ~ n 1
INT DC
UNKNOWN
0 HlGH
6
VOLTS
OPP ARM
llhn CGRL
0 *n RHEOSTAT
,.m>'
C l l L
E Y T DC REXT Z~VI'
@ z v : :
UNKNOWN
HlGH
BIAS
OPP
MD"
5o*n
ARM
I0
MI
'I*
CGRL
RHEOSTAT
A X
C A S E
Ac n l r i
a. Check mechanical zero of meter.
b.
Turn GENERATOR switch t o the
B A T CHECK position. If the meter
pointer i s not i n the B A T sector,
replace the batteries.
c. Turn GENERATOR switch t o the
desired generator source. The OSC
L E V E L control affects only the in-
ternal osci llator.
d.
Turn
ORTHONULL@
switch t o
OUT and PARAMETER switch t o G.
e. Turn CGRL d i a l near 11.
f.
Adiust D E T SENS control for
about 6 divisions deflection.
g. Turn MULTIPLIER switch for
minimum reading t o the l e f t of center
i f making a dc measurement. N u l l
as usual i f making an ac measure-
ment. (DQ rheostat not in the circuit.)
h.
Adiust CGRL d i a l for best ac
null, or zero the pointer i f using dc,
I f ac n u l l i s not sharp, a reactive
balance may be necessary, see
instruction manua
I.
i.
The unknown conductance i s the
CGRL-dial reading multiplied by
the MULTIPLIER switch setting.
i.
Turn GENERATOR switch t o
OFF.
i"H
I00
1
iiiu
1 10 100
lOOk lOk lk
mH
1
I0 I00
10 100 Ik
L s
-
LOW
o
( 0 0 2
TO 10)
L~
'LRdiC,
Q
" ' X
YRTCT
R X
mU
1 10 100
100 10 1
1 1ok 10 look H 100 1M
MuLT R A ~
a. Turn GENERATOR switch t o
B A T CHECK. If the meter pointer
isn't i n the B A T sector, replace
the batteries.
b .
Turn GENERATOR switch t o AC
E X T E R N A L or AC INTERNAL
1 kHz. Air core r f chokes should
be measured at a high frequency
(10 kHz) t o get a reasonable Q.
c. Turn PARAMETER switch t o
Ls.
d.
Connect unknown so that most
stray capacitance i s between the
LOW terminal and the 1650-B case.
e* Turn ORTHONULL@ switch
to
OUT.
f .
Turn OSC L E V E L clockwise.
The
ane el
control affects only the
internal oscillator. Use f u l l output
except for nonlinear unknowns.
Iron core inductors are often non-
I
rnear.
'
g. Turn DQ d i a l near
4
on the LOW
Q scale.
h.
Turn CGRL d i a l near 11.
i. Adjust D E T SENS for about 6
divisions deflection.
i.
Turn M U L T I P L I E R switch for
minimum meter reading.
k.
Alternately adiust the CGRL and
DQ dials for the best null, DQ d i a l
first, increasing the D E T SENS as
needed. N u l l means bring the point-
er as near t o the center of the
meter as possible. Usually it won't
be ~ o s s i b l e t o center the pointer.
I. ORTHONULL@
should be switch-
ed IN i f the DQ-dial reading times
f (kHz) approaches or i s less than 1.
m. If a sharp n u l l cannot be ob-
tained and the Q d i a l i s near 10,
switch t o
L
17'
n . The serles inductance of the
unknown equals the ~ r o d u c t of the
CGRL-dial reading and the MULTI-
PLIER-switch setting.
0.
The Q of the unknown equals the
Q-dial reading times
f
(kHz).
p. Turn GENERATOR switch OFF.
loo
P H
1
1
lo
10
loo
m H
loo
Ik