HP 204C User manual

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DI
15-1
WILS
GOVU
D
101.11
:
11-6625-1589-15-1
TM
11-6625-1589-15-1
TECHNICAL MANUAL
UNIVERSITY
OF
MINNESOTA
GOVERNMENT
PUBLICATIONS
LIBRARY
JAN 12 1989
U.S.
DEPOSITORY
PROPERTY
U.S.
-
G.P.O.
-
D
-
295
OPERATOR'S , ORGANIZATIONAL , DIRECT SUPPORT
GENERAL SUPPORT , AND DEPOT
MAINTENANCE
MANUAL
HEWLETT - PACKARD OSCILLATOR
MODEL 2040
HEADQUARTERS , DEPARTMENT OF THE ARMY
NOVEMBER 1971
GP STORAGE

TM
11-6625-1589-15-1
Information in this publication has been furnished under United States Government
Contract No. DA 28-043 - AMC - 01693 ( E ) and shall not be either released outside the
government , or used , duplicated , or disclosed in whole or in part for manufacture
or procurement without the written permission of the Hewlett - Packard Company .
* TM 11-6625-1589-15-1
TECHNICAL MANUAL
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON , D.C. , 3 November 1971 No. 11-6625-1589-15-1
Operatoris
,
Organizational
,
Direct
Support
,
General Support
,
and
Depot
Maintenance
Manual
HEWLETT - PACKARD OSCILLATOR MODEL 204C
TABLE OF CONTENTS
Section
I
.
INTRODUCTION
1-1
.
Scope
..
1-2
.
Indexes
.
1-3
.
Forms
and
Records
.
1-4
.
Technical
Characteristics
.
1-5 .
Description
. ..
1-10
.
Options
Available
.
1-12 . Items Comprising an Operable Equipment .
Page
1-1
1-1
1-1
1-2
1-3
1-3
1-3
.
2-5
.
Section
II
INSTALLATION
2-1
.
Introduction
2-3
.
Initial
Inspection
Power
Requirements
.
2-8
.
Grounding
Requirements
2-11
.
Installation
2-13 .
Bench
Mounting
2-15 .
Rack Mounting
.
2-17
.
Combination
Mounting
.
2-19 . Repackaging for Shipment
Page
2-1
2-1
2-1
2-1
2-1
2-2
2-2
2-2
2-2
2-2
.
.
* This technical manual is an authentication of the manufacturer's commercial
literature and does not conform with the format and content specified in AR 310-3 ,
Military Publications . This technical manual does , however , contain available
information that is essential to the operation and maintenance of the equipment .
i

11-6625-1589-15-1
TABLE
OF
CONTENTS
(
CONT
)
Section
III
.
3-7
.
.
Page
3-1
3-1
3-1
3-1
3-1
3-1
3-
2
3-5
3-5
3-5
3-6
3-7
OPERATING
INSTRUCTIONS
3-1
.
Introduction
.
3-3 . Instrument Description
3-5
.
Turn
-
on
Procedure
.
Operating
Considerations
3-8
.
Floating
Output
3-10 . Synchronization
3-13 . Low Distortion
3-15 . Battery Operation
3-16 . Rechargeable Battery Operation
3-22
.
Recharging
Nickel
-
Cadmium
Batteries
3-29 . Cycle - life of Nickel Cadmium Batteries
.
Section
IV
PRINCIPLES
OF
OPERATION
.
4-1
.
Introduction
.
.
4-3
.
Block
Diagram
Description
4-4
.
Bridge
and
Amplifier
4-10
.
Peak
Comparator
4-12
.
AGC
.
4-14
.
600
Ohm
Attenuator
Page
4-1
4-1
4-1
4-1
4-2
4-2
4-2
.
.
.
.
.
Section
V
MAINTENANCE .
5-1
.
Introduction
5-4
.
Performance
Checks
5-6
.
Dial
Accuracy
Check
.
5-7
.
Flatness
Check
.
5-8
.
Distortion
Check
.
5-9
.
Output
Voltage
and
Impedance
Check
5-10 . Output Control Check .
5-11 . Sync Output Check
5-12
.
Sync
Input
Check
.
5-13
.
Balance
Check
.
5-14 . Hum and Noise Check
5-15 . Adjustment and Calibration Procedures
5-16
.
Introduction
.
5-19 .
Power Supply
.
5-21
.
Bias
Adjustment
5-22
.
AGC
Adjustment
5-23 . AGC and Frequency Adjustment
5 - 24
.
High
Frequency
Adjustment
5-25
.
Distortion
Adjustment
.
5-26 . Troubleshooting Procedure
Page
5-1
5-1
5-1
5-1
5-2
5-4
5-5
5-6
5-6
5-6
5-7
5-7
5-9
5-9
5-9
5-9
5-9
5-9
5-10
5-10
.
.
.
5-11
ii

TM
11-6625-1589-15-1
TABLE
OF
CONTENTS
(
CONT
)
Section
VI
CIRCUIT
DIAGRAMS
6-1
.
Introduction
6-3
.
Schematic
Diagrams
6-5
.
Component
Location
Diagrams
Page
6-1
6-1
6-1
6-1
.
.
Appendix
A. REFERENCES
.
A - 1
.
B.
MAINTENANCE ALLOCATION
A
-
2
:
iii

TM
11-6625-1589-15-1
SECTION 1
INTRODUCTION
1-1 .
SCOPE .
This manual describes the Hewlett - Packard Oscillator Model 204C and covers
its operation , and organizational , direct and general support , and depot mainten
ance . It includes troubleshooting and replacement of parts available to organiza
tional , DS , GS , and depot maintenance personnel .
1-2
.
INDEXES OF PUBLICATIONS .
a .
Refer to the latest issue of PA Pam 310-4 to determine whether there are
new editions , changes , or additional publications pertaining to this
equipment .
b
.
Refer to the latest issue of 310-7 to determine if there are current ,
applicable modification work orders . ( MWO's ) pertaining to this equipment .
1-3 .
FORMS AND RECORDS .
a
.
REPORT OF MAINTENANCE AND UNSATISFACTORY EQUIPMENT . Use equipment forms
and records in accordance with instructions in TM 38-750 .
b
.
REPORTS OF PACKAGING AND HANDLING DEFICIENCIES . Fill out and forward
DD Form 6 ( Report of Packaging and Handling Deficiencies ) as prescribed in
AR - 700-58 ( Army ) , NAVSUP Publication 378 ( Navy ) , AFR 71-4 ( Air Force ) and
MCO
P4030.29
(
Marine
Corps
) .
C.
DISCREPANCY IN SHIPMENT ( DISREP ) ( SF361 ). Fill out and forward Discrepancy
in Shipment Report ( DISREP ) ( SF361 ) as prescribed in AR 55-38 ( Army ) ,
NAVSUP Pub 459 ( Navy ), AFM 75-34 ( Air Force ) and MCO P4610.19 ( Marine
Corps
) .
REPORTING OF EQUIPMENT MANUAL IMPROVEMENTS . Report of errors , omissions ,
and recommendations for improving this manual by the individual user is
encouraged . Reports should be submitted on DA Form 2028 ( Recommended Changes
to DA Publications ) and forwarded direct to : Commanding General , U.S.Army
Electronics Command , ATTN : AMSEL - ME - NMP - EM , Fort Monmouth , New Jersey 07703 .
1-1

TM
11-6625-1589-15-1
1-4 .
TECHNICAL
CHARACTERISTICS
RANGES
Frequency : 5 Hz to 1.2 MHz in 6 overlapping ranges ,
PERFORMANCE
RATINGS
Dial
Accuracy
:+3%
of
frequency
setting
.
Flatness
:
At
maximum
output
into
6000
load
1
kHz
reference
.
Sync Input : Oscillator can be synchronized to ex
ternal
signal
.
For
5
V
rms
input
,
sync
frequency
can
be
as
much
as
£
7
%
away
from
set
frequency
(
sync
range
).
Sync
range
is
a
linear
function
of
sync
voltage
.
Low
Dist
.
Mode
$
1
%
+
0.5
%
+
1
%
+
5
%
Normal
Mode
+
0.5 %
+
1
%
-1
%
100
300k
1.2M
THz
)
Distortion
:
GENERAL
Operating
Temperature
:
Instrument
will
operate
within specifications from
0 ° C to 55 ° C .
Storage Temperature : -40 ° C to + 75 °C.
Power : Standard : AC - Line 115V or 230 V + 10 % ,
50 Hz to 400 Hz , < 4W .
Opt 01 : Mercury batteries 300 hours opera
tion
Opt
02
:
Line
/
Rechargeable
batteries
115V
or
230V
+ 10 % , 50
Hz
to
400
Hz
,
<
4W
.
40
hours
operation
per
recharge
NORMAL
MODE
LOW DIST . SODE
0.35
Dimensions
:
6-3
/
32
"
high
,
5-1
/ 8 "
wide
,
8"
deep
(
155
x
130,1
x
203,2
mm
) .
0.1
100
200
PORQUENCY
Weight : Net 6 lbs ( 2,7 kg )
Shipping
8
lbs
(
3,6
kg
)
Hum
and
Noise
:
Less
than
0.01
%
of
output
.
OUTPUT CHARACTERISTICS
Output Voltage : 2.5V ims ( 10mW ) into 6000 ;
SV
rms
open
circuit
:
Output
Impedance
:
600N
at
any
attenuator
setting
.
Output
Control
:
>
40
dB
range
;
continuously
ad
justable
.
Output
Balance
:
>
40
dB
below
20
kHz
.
Can
be
floated
up
to
500V
peak
between
output
and
chassis
ground
.
SYNCHRONIZATION
Sync
Output
:
Sine
wave
in
phase
with
output
;
1.7V
rms
open
circuit
;
impedance
10 kn
.
1-2

TM
11-6625-1589-15-1
1-5 . DESCRIPTION .
1-6 . The Model 204C is a stable signal source that produces sine wave frequencies
between 5 Hz and 1.2 MHz in six ranges . The output level is variable from 0 to 5
volts rms from a constant 600 ohm source . When working into a 600 ohm load , the
maximum output level is 2.5 volts rms .
1-7 . A SYNC feature is included in the Model 204C . The SYNC jack on the front
panel provides an output sync voltage of 1.7 V rms , or accepts an external signal to
synchronize the oscillator . This feature permits several oscillators to be synchronized
to the same frequency or harmonics thereof .
1-8 . The output of the Model 204C may be isolated from the cabinet . This floating
output is balanced to better than 40 dB below 200 kHz with an isolated , battery oper
ated instrument , or better than 40 dB below 20 k ! lz with an instrument having an ac
line connection .
1-9 . The standard Model 204C contains an ac power supply that can be operated
from 115/230 volts ac , 50 to 400 Hz . The instrument is also available with a
mercury battery power supply as an Option 01 , or with a rechargeable nickel cad
mium battery power supply as an Option 02. The various power supplies can easily
be interchanged by removing the instrument covers , unplugging one supply and
plugging another in its place .
1-10
.
OPTIONS
AVAILABLE
.
1-11 . The following power supplies are available in kit form for field installation :
-hp- 11107A AC Power Pack ( standard )
-hp - 111084 Mercury Power Pack ( Option 01 )
-hp- 11109A Rechargeable Battery / AC Power Pack ( Option 02 )
1-12
.
ITEMS COMPRISING AN OPERABLE EQUIPMENT .
FSN Item
Quantity
Height
(
in
)
Depth
( in )
Width
(
in
)
Weight
( lb )
5895-177-1400
1
6-3 / 32
8
5-1
/
8
6
Hewlett
-
Packard
Oscillator Model
204C
1-3

2
2

TM 11-6625-1589-15-1
SECTION
II
INSTALLATION
2-1 . INTRODUCTION .
2-2
.
This
section
contains
information
and
instructions
necessary for
installing
and
shipping
the
Model
204C
Oscillator
.
Included
are
initial
inspection
procedures
,
power
and grounding
requirements
,
installation
information
, and
instructions
for
repackaging
for
shipment
.
2-3 . INITIAL INSPECTION .
2-4 . This instrument was carefully inspected both mechanically and electrically
before shipment . It should be physically free of mars or scratches and in perfect
electrical order upon receipt . To confirm this , the instrument should be inspected
for physical damage that occurred in transit . If
the
instrument
was
damaged
in
transit , refer to paragraph 1-3 . Check for supplied accessories , and test
the electrical performance of the instrument using the procedure outlined in
Paragraph 5-4 .
2-5 . POWER REQUIREMENTS .
2-6 . The standard Model 204C will operate from any source of 115 or 230 volts
( + 10 % ) , at 50 to 400 Hz .
With the
instrument
disconnected
from the ac power
source , move the voltage selector switch ( located on the rear panel ) so the desig
nation appearing on the switch matches the nominal voltage of the power source to
be used . Power dissipation is less than 5 watts .
2-7 . Line voltage requirements for Option 02 ( Rechargeable Nickel - Cadmium
battery supply are identical to those given in Paragraph 2-6 for the standard Model
204C
.
2-8
.
GROUNDING
REQUIREMENTS
.
2-9 . To protect operating personnel , the National Electrical Manufacturer's
Association ( NEMA ) recommends that the instrument cabinet be grounded . The
standard Model 204C is equipped with a three - conductor power cable which , when
plugged into an appropriate receptacle , grounds the instrument . The offset pin on
the power cable three - prong connector is the ground wire .
2-10 . To preserve the protection feature when operating the instrument from a
two - contact outlet , use a three - prong to two - prong adapter and connect the green
pigtail on the adapter to ground .
2-1

TM
11-6625-1589-15-1
2-11 . INSTALLATION .
2-12 . The Model 204C is fully transistorized ; therefore , no special cooling is re
quired . However , the instrument should not be operated where the ambient temp
erature exceeds 55 ° C ( 131 ° F ) .
2-13 . BENCH MOUNTING .
2-14 . The Model 204C is shipped with plastic feet and tilt stand in place , ready for
use as a bench instrument .
2-15 . RACK MOUNTING .
2-16 . The Model 204C may be rack mounted by using an adapter frame ( -hp- Part
No. 5060-0797 ) . The adapter frame is a rack frame that accepts any combination
of -hp- submodular units . It can be rack mounted only .
2-17 . COMBINATION MOUNTING .
2-18 . The Model 204C may be mounted in combination with other submodular units
by using a Combining Case ( -hp- Model 1051A or 1052A ) . The Combining Case is
a full - module unit which accepts various combinations of submodular units . Being
a full - module unit , it can be bench or rack mounted and is analogous to any full
module unit .
2-19 . REPACKAGING FOR SHIPMENT .
2-20 . The following paragraphs contain a general guide for repackaging of the
instrument for shipment . Refer to Paragraph 2-21 if the original container is to
be used ; 2-22 if it is not .
2-21 . If original container is to be used , proceed as follows :
a
.
Place instrument in original container if available .
b
.
Ensure that container is well sealed with strong tape or metal bands .
2-22 . If original container is not to be used , proceed as follows :
a .
Wrap instrument in heavy paper or plastic before placing in an inner
container .
b .
Place packing material around all sides of instrument and protect panel
face with
cardboard strips
.
C.
Place instrument and inner container in a heavy carton or wooden box and
seal with strong tape or metal bands .
d
.
Mark shipping container with " DELICATE INSTRUMENT " , " FRAGILE "
etc.
2-2

TM 11-6625-1589-15-1
SECTION III
OPERATING INSTRUCTIONS
3-1 . INTRODUCTION .
3-2
.
This
section
contains the
information
necessary for
operation of
the
Model
204C
.
or
3-3 . INSTRUMENT DESCRIPTION .
3-4 . Each operating control , indicator , and connector on the front and rear panels
is
identified
and
described
in
Figure
3-1 .
t
3-5 . TURN ON PROCEDURE .
3-6 . To turn on the standard Model 204C , proceed as follows :
S
a
.
Set the two - position voltage selector switch on the rear panel to the value
of
available
line
voltage
.
b
.
Connect
AC
Power
Receptacle
to
power
line
voltage
.
c
.
Switch
RANGE
switch
from
OFF
to
desired
frequency
range
.
d
.
Select desired frequency and voltage output with frequency dial and amp
litude
controls
respectively
.
3-7 . OPERATING CONSIDERATIONS .
3-8 . FLOATING OUTPUT .
3-9 . The Model 204C chassis can be isolated from ground by disconnecting the
grounding strap between the chassis and ground terminals on the rear panel . With
the chassis isolated , the output may be connected to an instrument or a circuit with
out regard to dc potential difference ( up to + 500 volts ) .
3
-
L

TM
11-6625-1589-15-1
3-10
.
SYNCHRONIZATION
.
3-11 . To synchronize the Model 204C connect a signal to the SYNC terminal on the
front panel . An input signal of 5 volts rms may vary as much as = 7 % in frequency
and still
synchronize
the
output
at set
frequency
.
(
3-12 . The SYNC terminal also provides an output sync voltage of 1.7 volts rms at
the same frequency as the Model 204C output .
NOTE
.
THE MODEL 204C CAN BE SYNCHRONIZED TO ANY SIGNIFICANT HARMONIC
OF
AN
EXTERNAL
SIGNAL
,
HOWEVER , IF A NON - SINUSOIDAL WAVEFORM IS USED
TO SYNCHRONIZE THE MODEL 2040 , SOME PORTION OF THE EXTERNAL SYNC SIGNAL
WILL BE FED TO THE OUTPUT . THIS SMALL SIGNAL WILL APPEAR AS DISTORTION .
THE AMOUNT OF THIS EXTERNAL DISTORTION WILL BE DIRECTLY PROPORTIONAL TO
THE AMPLITUDE OF THE SYNC SIGNAL .
FOR A NON - SINUSOIDAL SYNC INPUT OF
2 VOLTS PEAK - TO - PEAK , THE DISTORTION WILL BE DOWN ABOUT - 45 DB FOR FRE
QUENCIES WHICH ARE NORMALLY DOWN - 60 DB .
3-2

TM
11-6625-1589-15-1
1
204C
OSCILLATOR
NEWLETT PACKANO
11
3
2
( 0
)
سليست
$
RANGE
1100
AMPUTUDE
7
TO
TOK
Clo
20
NON
CHANGE
RCO .
Slow
1
LOO
NORN
Ost
.
or
S
( 10 )
SYNC
6
5
STANDARD
POWER
SUPPLY
CHAROC
RATC
SLOW
T01
7
eo
NOTE
CHANOC
FREO
SLOWLY
1
LOW
NORM
019T
.
WT
CHANGE
FRCO
SLOWLY
I
LOW
MORN
DIST
.
10 ) (
10
)
OPTION OI
POWER SUPPLY
OPTION
02
POWER
SUPPLY
P / O Figure 3-1 . Description of Controls , Indicators and Connectors
3-3

TM
11-6625-1589-15-1
3.
3
1
RANGE
Switch
:
Selects
frequency
range
.
In
OFF
position the
oscillator
is
inoperative
.
2
Frequency Dial : Selects frequency within desired range . Dial
calibration multiplied by RANGE switch position indicates output
frequency .
3
Frequency Vernier : Provides fine tuning of frequency dial .
4
AMPLITUDE Control : Selects desired output level from 0 to 5
volts rms . ( 2.5 volts rms into 600 ohms ) .
5
Output Terminals : Provides a 600 ohm output at a frequency and
amplitude determined by control settings .
6
SYNC
:
1.
Provides
an
input
for
an
external
sync
signal
.
2. Provides an output sync signal of 1.7 volts rms .
7
Ground Strap : Connects the floating circuit chassis to ground .
8
Voltage Selector Switch : Selects line voltage of 115 volts or 230
volts
ac
.
9
AC Power Receptacle : Mates with AC power cord supplied with
this
instrument
for line
voltage connection
.
(
10
)
NORM / LOW DIST . Switch : Selects normal or low distortion on
the X5 and X10
ranges
( see
Paragraph 3-14
) .
(
11
)
CHARGE RATE Switch : ( Option 02 only ) Selects SLOW or FAST
rate of recharging the nickel - cadmium cells .
P / o Figure 3-1 . Description of Controls , Indicators and Connectors
3-4

IM
11-6625-1589-15-1
3-13 . LOW DISTORTION .
3-14 . At frequencies below 200 Hz , distortion can be reduced by switching the
NORM / LOW DIST switch on the rear panel to LOW DIST . In the LOW / DIST mode
the Model 204C will have a longer settling time when changing frequencies . To
avoid this , set the desired frequency before switching to the LOW / DIST mode .
NOTE
The
Model
204C
output
may
appear
unstable
, or
drop
to
zero
when
turning
the
frequency
dial
rapidly
or
changing
the
RANGE
switch
while
in
the
LOW
/ DIST
mode
.
3-15 . BATTERY OPERATION .
3-16 . RECHARGEABLE BATTERY OPERATION .
3-17 . There is no change in the operating procedure for an instrument in which the
rechargeable battery supply has been installed . However , this power supply per
mits either ac operation for 115/230 vac + 10 % ( selected by switch on rear ) 50 to
400 Hz power sources or battery operation for portable applications . Battery oper
ation only ( with charger power cord disconnected ) is required at temperatures below
32 ° F (0 ° C) and is recommended at temperatures above 104 ° F ( 40° c ) .
3-18 . When the RANGE switch is turned OFF , power is removed from the oscillator
portion of the instrument and a resistor is connected across the output of the power
supply . The charger will continue to operate as long as the power cord is connected
to a power source . The
resistor
,
placed across
the
output
of the
power supply
, acts
as a load in place of the oscillator section to maintain a constant charge rate through
the
batteries
. A diode in the output
circuit prevents battery discharge
when the
oscillator
is
not
connected
to a
power
source
.
3-19
.
It
is
recommended
that
the
power
cord
be
connected
to
a
power
source
when
ever
possible
.
This
will
prevent
self
- discharge
of
the
battery
cells
and
will
assure
a
fully
charged
battery
whenever
portable
operation
is
required
.
Turn
the
oscillator
OFF
when
not
in
use
,
particularly
when
operating
with
the
power
cord
disconnected
.
3-20 . When fully charged , the batteries will power the oscillator for approximately
35
hours
of
continuous
or
intermittent operation provided
they are at a
temperature
of 81 ° F £ 10 ° . If the
batteries
are
operated
at
higher
or
lower
temperatures
their
capacity
is
reduced
as the
temperature extremes
are
approached
;
approximately
28
hours at 122 ° F ( 50 ° C ) or approximately 20 hours at -4 ° F ( -20 ° C ). At temperatures
beyond these extremes the batteries are not capable of supplying their character
istic stable
discharge
voltage
.
3-21 . The + 122 ° F to -4 ° F temperature range is adequate for most users , however ,
keep these limits
in
mind when operating under field conditions
.
Internal temper
atures
in
excess
of
122
° F
are easily
obtained
if
the
instrument
is left in
the sun
,
3-5

TM
11-6625-1589-15-1
even with a moderate ambient temperature . Good practice would be to avoid stor
ing , transporting , or operating in direct sunlight other than for a very short period .
Also avoid placing the instrument in a location where surrounding equipment might
excessively raise the internal temperature .
CAUTION
THE HERMETICALLY SEALED CELLS IN THESE
BATTERIES MAY BE PERMANENTLY DAMAGED OR
THEIR LIFE DRASTICALLY REDUCED IF EXPOSED
TO EXTREMELY HIGH TEMPERATURES . THIS DAN
GER INCREASES UNDER PROLONGED CONDITIONS .
3-22 . RECHARGING NICKEL - CADMIUM BATTERIES .
3-23 . The batteries should be considered fully discharged when the voltages drop
below = 11V at the B + and B- test points . The batteries will not operate much long
er when this point is reached , and the oscillator may not meet specifications . Ex
cessive discharge may shorten battery life .
3-24 . A symptom of low battery voltage is clipping of the output waveform . If only
one peak is clipped , however , check the BIAS voltage for proper setting . See Para
graph 5-21 for BIAS adjustment .
3-25 . To recharge batteries , select either FAST or SLOW charge rate and 115V or
230V ac on rear panel and connect power cord to suitable power source . The oscil
lator can be used during recharging since the charge rate is the same whether the
oscillator
is
off
or
operating
.
3-26
.
The
FAST
charge
rate
should
be
used
only
when
aquick
charge
is
necessary
.
Repeated
charging
at
a
FAST
rate
will
shorten
battery
life
.
3-27 . The batteries will be fully charged in approximately 60 hours at the 6 mA
SLOW charge rate , and 15 hours at the 20 mA FAST rate if they were fully discharged
initially .
3-28 . The batteries can be charged at any temperature between + 320F and + 1040F
( 0 ° C to + 40° C ) . However , to obtain optimum battery life , recharging should be done
at a temperature of 80. 6 ° F + 10 ° F ( 270 C + 5.6 ° C ) .
CAUTION
THE FOUR NICKEL - CADMIUM BATTERIES ARE
HERMETICALLY SEALED AND CAN BE DAMAGED
IF CHARGED AT A FAST RATE AT TEMPERATURES
ABOVE
104
°
F
(
40
°
C
)
.
DO
NOT
CHARGE
AT THE FAST
RATE
FOR
MORE
THAN
15
HOURS
.
3-6

TM
11-6625-1589-15-1
3-29 . CYCLE - LIFE OF NICKEL - CADMIUM BATTERIES .
.
3-30 . As extremes in temperature are approached , the cycle - life ( complete charge
discharge cycles ) of the batteries is reduced . Storage at high temperatures will
increase the self - discharge rate and also decrease the cycle - life . Permanent bat
tery damage may result if the batteries are stored at a high temperature for a pro
longed period .
3-31 . Battery cycle - life can be extended by recharging before the batteries are
completely discharged , by charging at the SLOW rate , and by not overcharging .
3-32 . The cycle - life of the batteries is based , by the manufacturer , on an end
point of 80 % of the rated 225 milliampere - hour capacity . This is with a ten hour
charge and discharge current of 22.5 milliamperes with discharge carried to the
normal ten - hour end voltage ( 1. 10 volts / cell x 5 = 5.50 volts / battery ) on every
cycle . Under these conditions a cycle - life in excess of 100 cycles can be expected .
3-33 . When used to power the Model 204C , the batteries are discharged at approxi
mately a 35 hour rate . The batteries are not fully discharged if they are recharged
as recommended in Paragraph 3-22 .
3-34 . Optimum battery life can be obtained by following these precautions :
a
.
Prevent
complete
battery
discharge
.
b
.
Keep FAST charges to a minimum .
C.
Operate at moderate temperatures when possible .
d
.
Disconnect power cord after 60 hours of continuous charging with oscillator
turned OFF ( 15 hours if charging batteries at a FAST rate ) .
:
3-7