Swann CUBIC ASTRO 102 BX User manual

SERVICE
MANUAL
. ASTRO 102 BX
. TRANSCEIVER
eCUBIC .
. COM~UNICATIONS.INC.
5 .. 18,. DIVISION

····~SllvAN.
Adlvision of Cubic Communications, /nc.
To the Service Technician:
The ASTRO-I02BX is a modern, top-of-the-line, sophisticated
Amateur Band Transceiver utilizing state-of-the-art techniques
and design. The features that today's Hams want are built into
the unit, not marketed as "add on" accessories at extra cost
dual PTO's, Passband Tuning, Full or Semi Break-in, VOX, ew
Sidetone, RIT, Notch Filter, and more.
Whenever performance measured up to required standards, inte-
grated circuit technology was used in the design; where special
functions were required, or desired performance could not other-
wise be obtained, carefully designeddiscrete component circuits
were included, rather than accept compromised performance.
Every care has been taken to providelong, trouble-free life,
but the requirements of extra operating features, high perform-
ance design, and compact packaging demanded by today's Hams
results .in a unit necessitating a high degree of skill on the
part of you, the Service Technician. Tc assist you, this manual
has been painstakingly prepared. Take the time to thumb through
it; read and study the Theory of Operation section and the
Servicing Hints section; it will he time weIl spent, even for the
most highly qualified and experienced personnel.
It is you, the Service Technican, that will ultimately determine
how weIl or how poorly the radio will work, and therefore how
satisfied or dissatisfied our customers will be, in the long run.
If you have a suggestion or a problem, write or call our service
department. We'll listen, and help you all we can.
Sincerely,
CUBIC CO ICATIONS, INC.
D' ision
tV---
Sam"F. Am, K6TSD
President
SFA/lb
305 Airport Rd .• Oceanside, Ca. 92054 •Telephone [phone] Telex: 695435; ANS BK: CUBICOM, OCEN.

OCUBIC
CDMMUNICATIDNS
S""AItI DIVISIDN
Section One
General Information •••••• •••••••••••• ••••• ~·.l.l
Section Two
Specifica tions •••••••••••••••••••••••••••••• 2-1
Section Three
Receiver Theory of Operation •••••••••••••••• )-l
Section Four
Transmitter Theory of Operation ••••••••••••• 4-1
Section Five
Oscillator Theory of Operation •••••••••••••• 5-1
Section Six
Ancillary Circuits Theory of Operation •••••• 6-1
Section Seven
Servicing Hints ~ ................•.• .• ?-l
Section Eight
Servicing Data •••••••••••••••••••••••••••• ~ .8-1
Section Nine
Parts 1ists ••••••••••••••••••••••••••••••••• 9..;1
Since Cubic Communications is constantly striving to improve its
products, it reserves the right to make changes withoutnot1ce or
obligation.
The information contained in this document is the property of Cubic
Communications in conjunction with operating and maintaining the
ASTRO 102BX Transceiver. This information may not be copied, re-
printed, or disclosed to a third party, either wholly or in part,
without the written consent of Swan Division, Cubic Communications.
Entire contents@) 1980 by Cubic Communications.

-- ~~M~!~ATIC)NS
S.,.AIfI DIVISION
The Swan ASTRO l02BX is a 160M through lOM SSBamateur transceiverthat
features dua1 PTO's and frequency counter for splitfrequency operation with
digital frequency readout. Frequency selection is the only tuning necessary
when operating into a matched antenna with a VSWR of 1.7:1 or less.
Standard features include: Full break-in or semi-break-in CW operation;
narrow band crystal CW filter; two position CW transmit pulse shaping; VOX;
noise blanker; SSB transmit speech processor; true RF and IF gain controls;
peak reading wattmeter with FWD, REF, and ALC positions; variable AGC decay;
passband tuning; and audio notch filter. The basic single conversion design
has been proven in thousands of the popular Swan transceivers. Mechanical
and electrical designs are exceptional, for years of trouble-free operation,
even in a rugged mobile environment.
The unit is designed for fixed and mobile use with minimum interconnec-
tions. For fixed station operation an auxiliary speaker/power supply, model
psu-6, provides 13.6 V IC from 115/230 V AC. A matching antenna tuner, model
STZA, is also available.
The transmitter may be used for RTI'Y or Slow Scan TV, but operation in
these modes requires additional forced air cooling. See the operator's an-
ual for precautions to be observed when operatingin these modes. The ASTRO
l02BX includes automatic gain control (AGC) in the receive mode, and auto-
matic level control (ALC) in the transmit mode. CW sidetone is also provided.
~~::::=======:::~~;.;.;;.------------_.

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OCUBIC
COMMUNICATIONS
SIVA_ DIVISION
~]p)~<Cll ~nCC(&û:n(Q)ffu~
General
Frequency Coverage*
160M. o ••••.••••••• ••• 1.8-2.0 MHz
80M •••••••••••••••• 3.5-4.0 MHz
40M •••••••••••••••• ?. O-? •5 MH:z
20M •••••••••••••••• 14.0-14.5 MHz
1.5M •••••••••••••••• 21.0-21.5 MHz
-lOM •••••••••••••••• 28.0-28.5 MHz
28.5-29.0 MHz
29.0-29.5 MHz
29.5-29.999 MHz
*Approximately 50 to 100kHz overrange provided on each band.
Frequency Control: Dual PrO with 6-digit frequency counter and RIT control.
PTO Modes of Operation: A only; Receive A-Transmit B; B only; Receive B-
Transmit A; External LO.
Modes of Operation: 88B with selectable sideband. CW with automatic 800 Hz
offset on transmi tand full or semi-l:n:'eakin.
Power Input Requirements: 12-14 V :IX: negative ground only. No damage up
to 15 V:IX:. 20 amperes peak current.
Electromagnetic Interference:
Transmit:
Receive:
Five element low pass filter on each band.
Five element lowpass filter plus three pole bandpass
filter on each band.
Dimensions: 6.375" H x 14.25" Wx 13.25" D
16.2 cm x 36.2 cm x 33.7 cm
Weight: 23.5 pounds (10.6 kg)
Rear Panel:
Power connector:
Pin 1
2
3
4
5
6
13.6 V :IX:
Ground
Ground
(used for accessories)
13.6 V:IX:
Ground
13.6 V :IX: fused to 3amps (used for accessories)
Antenna connector: UHF (80-239)
External speaker/phones: Phone jack
External relaYl RCA jack
2-1

OCUBIC
COMMUNICATIONS
SIIW .. III DIVISION
Key:
RCA jack
EXT. Modulation: RCA jack
Receiver Selectivity: SSB and CW--2.4 kHz OOndwidth, two 8-pole crystal
filters with shape factor 1.4; 6 dB to 100 dB
Fuse:
Ext. L.O.:
Circuit Design:
Receiver Sensi-
tivity:
Image Rejection:
Passl:and Tuning:
Dynamie Range:
Audio
Output Power:
Meter:
Circuit Design:
Power Input:
Power Output:
Unwanted Sideband
Rejection:
Harmonie Output:
3 amp fast blow
RCA jack
R
.1
ecelver
Single conversion to 9.00165 MHz IF using double 001-
anced mixer. Exceptional immunity to overload and cross
modulation.
10 dB S+N/N typical at 0.35 uV
Better than 60 dB
CWN--300 Hz l:andwidth. IF crystal filter in series
wi th one 8 pole SSB filter
SSB and CW eight pole cutoff continuously variabIe
high pass or low pass. LED readout shows equivalent
audio passband.
CWN--IF crystal filter continuously tunable over 300 to
3000 Hz with passband control
AGC greater than 100 dB; third order intercept +15 d.Bm
Greater than 3 watts into 4ohms.
S-units from 1 to 9; 20, 40 and 60 dB over S-9
Transmitter
Excellent hannonic and TV1 suppression. ALC limits SSB
peak power and CW power to 100 watts output.
235 watts PEP input at 13.6 V 00 input
100 watts PEP into 50 ohm non-reactive load at 13.6 V00
>60 dB down at 1000 Hz audio note
?45 dB below peak power level
Carrier SUPJlression: >50 dB below peak power level
2-2

_CUBIC
COMMUNICATIONS
SMFAIfI DIVIBION
Spurious Output:
Transmit Control:
(for SSB)
CW Transmit:
Microphone Input:
Audio Response:
Meter:
Coolingl
VSWR Shutdown:
> 55 dB below peak power level
PI'T and VOX standard
Full or semi-breakin with sidetone standard. Automatic
800 Hz offset on transmit frequency.
47 kO input impedance
)00 to )000 Hz i6 dB
In receive mode, reads S units and dB over S-9; in
transmit mode, reads peak power selected by meter
switch IForward power 106 watts full scale, reflected
power 10 watts full scale, or reads ALC.
Large capacity heat sink fins supplied. For SSTV, RTTY,
and semi-continuous transmit, forced air cooling such as
a small "muffin" fan on heat sink fins is required.
Full power up to VSWR= 1.7:1
Approximate limit ratio asfollows:
VSWR
1.7:1
2.0:1
).011
Open or short
Percent Power
100%--
80%
60%
25% (equivalent voltage)
"

OCUBIC
CDMMUNICATIDNS
5' •• ", DIVISIDN
Bandswitch and Low Pass Filters ••••••••••••••••• 3-l
Preselector oe ••••••••••••• •• 3-2
First M-ixer ••• ' •••••• 0 •••••••••••••••••••••••••• •3-3
Noise Blanker Gate •••••••••••••••••••••••••••••• 3-4
Filter, Buffer, and Post Filter Amplifier ••••••• 3-5
AGC Attenuator •••••••••••••••••••••••••••••••••• 3-5
Pass band Tuning ••••••••••••••••••••••••••••••••• 3-6
CW Narrow Filter •••••••••••••••••••••••••••••••• 3-7
Main I.F. Amplifier ••••••••••••••••••••••••••••• 3-8
Product Detector/Audio Mute ••••••••••••••••••••• 3-8
Notch Filter ...................•.•....•......... 3-9
Audio Power Amplifier/Receiver Mute ••••••••••••• )-9
Automatic Gain Control ••••••••••••••••••••••••• 3-l0

I
---------------------,
NarE: Component designations used in the "Theory" sections of this manual
are the shortened numbers as they appear on the schematic diagrams. To de-
termine complete component designation, the boardjlocation numbermust be
added af ter the letter or letters. See the "Note" in the first portion of
the "Parts" section of this manual.
Schematic diagrams contalned ~n the "Theory" sections of this manual
are simplified to help in the understanding of the operation of the circuit;
they may not always, therefore, be sufficient for troubleshooting purposes.
When servicing the equipment, it is urged that the technician use only the
schematic diagrams included in the "Servicing Data" porti on of this manual.
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RECEIVE ANTENNA
IWITC" IN.
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BANIBWITCH AND LOW PASS FILTER BOARD
---- -- --- ""'--..-;...;;;..
The received signal
from the antenna connec-
tor is passed through one
of six low pass filters,
which are also usedin
the transmit condition.
Each is composed of two
inductors and three cap-
acitors, yielding a five
pole filter for each band
(160
through 10 meters).
Note that the same filter
is used for all segments
of the 10 meter band.
The
filters are sel-
ected by SlOl and Sl02,
sections of the BAND sw-
i
tch. From SlOl, the
signal is passed to relay
KlOl, through C122, and
through Cl Ol. From there
it is routed to the input
of the preselector board.
Receiver antenna switch-
ing is accomplished by Kl Ol ,
which is activated by Ql02.
When the receive ("R") line
is high, as it is in the re-
ceive condition Ql02 is bias-
ed to saturation, energizing
KlOl and connecting C122 to
the output of the selected
low pass filter. Since the
collector of Ql02 is low when
it is thus saturated, QlOl is
in a non-conducting condition
and has no effect. However,
when the "R" line is low, as