HP 339A - Option 001 Voltmeter Performance and Parts; Option 001 Theory of Operation Notes

£bdel
3
39
A
MANUAL
CHANGES
Page
3
VOLTMETER PERFORMANCE
(Optiea 001).
Full-Scale
Accuracy
and Frequency
Response
Test:
33
9
A
lapat
Leval
339A
lapat
Range
33SA
20Hz
Reading
30kHz
Reading
Test Limits
(14%)
.0001
.0003
.0001
.0003
.000096. 000 104
.000288-000312
1
Input
Level
33 9
A
lapat
Range
339A
20Hz
Reading
339A
100Hz
Reading
339A
1kHz
Reading
339A
10kHz
Reading
33SA
20kHz
Reading
Test
Limits
U2%)
0001
.0003
.0001
0003
.000098-000102
.000294-.
000306
Input
Level
339A
lapat
Range
339A
80kHz
Reading
Test
Limits
1+10%.
-30%l
.0001
.0003
.0001
.0003
.000070-0001
1
.00021 -.00033
Replaceable
Parti:
The -hp-
339A
Distortion
Measurement
Set with
option
001 in-
stalled
uses an
A53
Analyzer/Power
Supply
assembly
instead of
an A3
Analyzer'Power
Supply. The
boards
are
electrically
the
same with the following
exceptions:
1
S4
has been
changed to
accommodate
the
two
additional
vo.'tmeter
input
ranges.
R127,
50.51Q, R126,
10kQ and
Cl
26,
lOOpF
are included
as
part of
the switch
assembly.
2.
C323.
C324,
and
R314
have changed
values.
Table
6-3a.
Replaceable
Parts
^Herenca
-bp- Pert
No.
Qty
Oescriptien
A53
00339-66553
1
Analyzer/Power
Supply
Assy.
S4
00339-61914
1
Switch
Assy,
Rotary
3100-1657
1 Switch.
Rotary
R1
26
0757
0442
1
Resistor-fxd
10k
.01 1/8
C
1 26
0160-4801
1
Capacitor-fxd
lOOpF
100V
R
1
27
0699-0053
1
Resistor-fxd
50.5
IQ
.25
00339-04014 1
Knob Assy.
INPUT
RANGE
1500-0580
2 Coupler,
Flex
3130-0552
1
Detent
C323 0180-0339
2
Capacitor-fxd
50uF 1
6V
C324
0180-0339
Capacitor-fxd
50uF 16V
R31
4
0683-1025
1
Resistor-fxd
Ik .05 1/4
Theory
of
Operation
The Input
Amplifier
operation
for
instruments
with
option
001 is
the
same
as that of
standard
instruments
except
that
two
simple
modifications
have
been
added to allow
for
the
two
additional in-
PJ^tanges.
First,
a
fourteen position
switch
replaces
the
twelve position
switch of the
standard
instrument.
This allows
the
output
at-
tenuation to
go to
OdB
when
either
. 1 mV or
.
3mV
input ranges
of
the
voltmeter are
selected.
Second, R1
2 7 la
50.510 resistor)
is included
as part of
the
four-
teen position switch
to add
10dB of gain
to the input
amplifier
when
the
.
ImV input range
of the
voltmeter
ts selected.
Other
A53 beard
cbeagei:
The value
ot R314 decreased
to
1
k
0
to reduce
1 20Hz pulses
picked
up
on the ImV
scale (due
to imbalance
in
power
supply
bypassing).
The
values of
C323
and
C324
are
increased
to improve
bypass-
ing
and stability
in the
2 5kHz to
50kHz region.
Cl
26 and R126 provide
input
compensation
needed to
prevent
oscillation
on the
0.1 mV range
with
a
high
impedance
source.
They
cancel the negative input
impedance
effects of
U100
Figure
8-2A is
a simplified
block
diagram of
the input
amplifier
of
Option
001
instruments. The
schematic
is
a
revised
version
cf
Figure 8-13
found
in the standard
instrument
Operating
and
Ser-
vice
Manual.
It
shows the electrical
modifications
performed
to
generate
an
-hp-
339A Option 001
instrument.
Other
board
changes:
Because
a different (shaft) coupler
is
used
on the INPUT RANGE
assembly,
C40 on the
oscillator
board needs
to be repositioned
as
per figure
below. When ordering
a
replacement
oscillator assembly
for
the 339
A
option 001
,
use
part number 00339-66551
. This
part
will come
with
C40
in
the proper place.
00339-66511
00339-66551
C
40