SAC SS-800AVS User manual

SOUTHERN A VIQNlC.,q COM.~A NY
MANUFACTURERS OF LOW FREOUENCY RADIOBEACONS AND ASSOCIATED PRODUCTS
MODEL SS-800AVS
NON-DIRECTIONAL RADIOBEACON
MANUAL #80AVS-90-2
BOX 5345, BEAUMONT, TEXAS 77726-5345 USA; TELEPHONE: [phone]; CABLF" SAC; TELEX: 77-9450: FAX: [phone]

___~--,-~ E
LIMI~D
ALL IMPLIED WARRANTIZS EXISTING UNDER ~ LAW AItE HY~EBY EXPRESSLY NEGATED;
pARTICOT2L~3IY, COMPANY HEItEBY N~GATES A~D DZSCLAIM~ T~ IMPLIED WARP,~NTY OF
KERCHANTA~ILITY A~D IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PVRPOSEo
If Purchaser believes that these goods do not comply with the express
warranty stated above or any existing and applicable implied warranty which
under the law canno~ be disclaimed or negated as provided above, then
purchaser may request that COMPAB~ inspec~ such goods by mailing, within
s ix~cy (60) days after purchaser k~ows or should have kno~ ~hat the goods
allegedly do not conform with the warranty, postage prepaid, to ~OM~ANY,
P.O. Box 5345, 5000 Belmont, Beaumont, Texas, 77726 Attention: President,
a writing specifying (a) purchaser’s name, address, and telephone mummer,
(b) date of purchase, (c) COMPANY distributor or location from which the
goods were purchased, (d) location of the goods in question (or include the
goods in question with the notice}, and (e} a brief description of the
alleged nonconformity with the warranty. If the goods are covered by, and
do not conform with, the warranty, COMPANY will repair or replace F.O.B.
point of manufacture any such goods; but in no event will COMPANY be
obligated or required to remove the non-conforming goods from their place
of installation or to install the replacement goods. All replacement goods
are warranted to the e~ent provided herein for the remaining te~ of ~his
warranty.
In the even~ purchaser chooses to commence an action for breach of warranty
or breach of con~rao~ arising out of the sale of the goods pursuan= to this
invoice, the purchaser must commence such action within one year after the
cause of action accrues.
THE RF--~EDY PROVIDED H~BEIN SHALL BE THE SOLE ~
EXCLUSIVEREMEDY
FOR
BREACH OF THIS ~%RP2%NTY, FOR ~ BR~ACR OF ANY IMI~LI~D WA/tR~A~TY EXISTING
AND APPLICABLE UNDER TH~ LAW (TO TH~ EXTENT THAT ANY SUC~ WARRAN~ HAS NOT
BEEN SUCCESSFULLY NEGATED AND DISClAIMeD KEREI~AROVE), AND FOR ~ ACT OF
N~GLIGENCY OR ANY OTHER TORTIOUS ACT COMMITTED BY COMPANY, AND IN NO EVENT
SHALL THE COMPANY ~E LIARLE TO PURCHASER OR ANY THIRD PAR~"~
FOR
ANY
INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES RESULTING FROM ANY DEFECT
IN
THE GOODS OR ~ FAILURE OF TH~ GOODS TO CONFORM WITH THIS WAR/%~ATTY OR
ANY
IMPLIED ~
EXISTING AND APPLICABLE UNDER THE LAW (TO T~E EXTENT
THAT
ANY SUCH IMPLIED ~ HA~ NOT BEEM SUCCESSFULLY NEGATED AND DISCLAIMED
~REINA~OVE ).

Table of Contents
1 INTRODUCTION ........................................... 1
i.I General Description: SS-800AVS ..................... 1
1.2 Specifications: SS-800AVS .......................... 3
1.3 General Description: PC-1000B ...................... 7
1.4 Specifications: PC-1000B ........................... 9
2 THEORY OF OPERATION, RADIOBEACON .......................
ii
2.1 Functional Description: SS-800AVS .................. ii
2.2 Detailed Circuit Analysis: SS-800AVS ............... 13
.... 2.2.1 Synthesizer PWB: .............................. 13
2.2.2 AM Oscillator PWB ............................. 17
2.2.3 Audio PWB (Optional) .......................... 21
2.2.4 Keyer ......................................... 25
2.2.4.1 Letter PWB ................................ 25
2.2.4.2 Number PWB ................................ 26
2.2.4.3 AM Recycle PWB ............................
26
2.2.5 Driver PWB ....................................
35
2.2.6 Final Stage ...................................
39
2.2.7 Power Supply ..........................
; ....... 41
2.2.8 Battery System ................................
45
2.2.9 AM Auto Shutdown PWB .......................... 49
2.2.10 Power Switch PWB Assembly ....................
53
2.2.11 Metering Circuit .............................
57
2.2.12 Reset SSC PWB ................................ 61
3 THEORY OF OPERATION, ANTENNA COUPLER ................... 69
3.1 FUNCTIONAL DESCRIPTION: PC-1000B .................. 69
3.1.1 Impedance Transformer ~..~ ..................... 69
3.1.2 Tuner ......................................... 69
3.1.3 Autotune ...................................... 69
3.1.4 Antenna Current/Tuning Meter ..................
69
3.2 DETAILED CIRCUIT ANALYSIS: PC-1000B ................ 71
3.2.1 Impedance Transformers: .......................
71
3.2.2 Tuner: ........................................ 71
3.2.3 Autotune ...................................... 73
3.2.4 Antenna Current/Tuning Meter ..................
77
4 ANTENNAS ...............................................
81
4.1 Mast Antenna .......................................
81
4.2 "H" Antenna ........................................
82
4.3 50-Foot Guyed Mast Antenna .........................
82
4.4 Symmetrical "T" Antenna ............................
83
5 INSTALLATION AND OPERATION .............................
85
5.1 Transmitter Installation ...........................
85
5.2 Coupler Setup ......................................
87
SS-800AVS Southern Avionics
Company
i

5.3 Synthesizer Adjustment ............................. 95
5.4 Antenna Tune-Up .................................... 99
5.5 Audio Mode Selection ...............................
103
5.6 Tone Modulation Adjustments ........................ 104
5.7 Transmitter Adjustments ............................
105
5.7.1 Autoshutdown and Audio Alignment .............. 105
5.7.2 Autoshutdown Adjustment - Nonvoice System .....
106
5.7.3 Automatic Shutdown Test .......................
106
5.7.4 Final .........................................
107
6 MAINTENANCE ............................................ 109
6.1 Cautions and Test Equipment List ................... 109
:~ 6.1.1 General~ Precautions ........................... 109
6.1.2 Specific Precautions ..........................
109
6.1.3 Test Equipment List ........................... 109
6.1.3.1 Field Service or Checkout .................
ii0
6.1.3.2 System Alignment and Calibration ..........
ii0
6.2 System Alignment and Calibration ...................
iii
6.2.1 AM Oscillator PWB .............................
iii
6.2.1.1 Preliminary ............................... iii
6.2.1.2 Frequency and Modulation Adjustment ....... iii
6.2.2 Audio PWB Adjustment .......................... 112
6.2.3 Antenna System Changes ........................ 112
6.2.4 Battery Charger Float Voltage Adjustment ...... 113
6.3 Preventive Maintenance .............................
115
6.3.1 Maintenance Log ............................... 115
6.4 Corrective Maintenance .............................
117
6.4.1 Index To Testpoints ...........................
117
7 PARTS LIST .............................................
127
8 MODIFICATIONS ..........................................
163
ii Southern Avionics SS-800AVS
Company

Table of Figures
Transmitter Enclosure Dimensions ......................... 2
Coupler Enclosure Dimensions .............................
8
Block Diagram ............................................
12
Synthesizer PWB Schematic ................................
14
Synthesizer PWB Assembly ..................................
15
Synthesizer Programming PWB Assembly .....................
16
AM Oscillator PWB Schematic .............................. 18
AM Oscillator PWB Assembly ............................... 19
Audio PWB Schematic ...................................... 22
Audio PWB Assembly ....................................... 23
Letter PWB Schematic .....................................
29
Letter PWB Assembly ......................................
30
Number PWB Schematic ..................................... 31
Number PWB Assembly ......................................
32
AM Recycle PWB Schematic .................................
33
AM Recycle PWB Assembly ..................................
34
Driver PWB Schematic .....................................
36
Driver PWB Assembly ...................................... 37
Final Stage Schematic ....................................
40
50 V Power Supply Schematic ..............................
42
50 Volt Power Supply ......................... , ...........
43
SSC Battery Standby Schematic ............................
46
SSC Battery Standby Assembly .............................
47
AM Auto Shutdown PWB Schematic ...........................
50
AM Auto Shutdown PWB Assembly ............................
51
Power Switch PWB Schematic ............................... 54
Power Switch PWB Assembly ................................
55
Meter PWB Schematic ...................................... 58
Meter PWB Assembly ....................................... 59
Meter Bracket Assembly ...................................
60
Auto Shutdown Reset PWB Schematic ........................
63
Reset SSC PWB Assembly ...................................
64
Transmitter Schematic ....................................
66
Transmitter Diagram ......................................
68
PC-1000 Block Diagram ....................................
70
PC-1000B Antenna Coupler Schematic .......................
72
Autotune Motor Drive PWB Schematic .......................
75
Autotune Motor Drive Pwb Assembly ........................
76
Antenna Current/Tuning Meter Pwb Schhematic ..............
78
Antenna Current/Tuning Meter PWB Assembly ................
79
Antenna Reactance ........................................
84
Antenna Coupler Cable Connections ........................
88
Impedance Transformer Taps ...............................
89
Mast Antenna and PC-1000 Mast Tuned for 190-415 KHz ......
90
Mast Antenna and PC-1000 Mast Tuned for 415-625 KHz ......
91
50 Foot Guyed Mast and PC-1000 ...........................
92
SS-800AVS Southern Avionics
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iii

Symmetrical "T" Antenna and PC-1000 ...................... 93
Synthesizer Bands ........................................ 97
Control and Testpoin Positions ........................... 98
iv
Southern Avionics SS-800AVS
Company

1 INTRODUCTION
1.1 General Description: SS-800AVS
This non-directional beacon is a dual carrier transmitter with an
adjustable output power of up to i00 watts. This is the power of
a single carrier° The second carrier is added to the first during
modulation. This produces a signal withan AM type waveform and an
SSB bandwidth. The bandwidth of a .dual carrier emission is the
same as the audio tone (either 1020 Hz or 400 Hz).
The transmitter operates on 115/230 VAC, 50/60 Hz or 48 VDC.
An automatic shutdown circuit is included that automatically shuts
down the transmitter if power falls below an adjustable level, if
the ident signal fails, or if extreme distortion is present. When
a dual system is used, the shutdown signal is used to transfer to
the standby transmitter°
A current and voltage limiter protects the transmitter from line
surges or voltage and current surges in the final due to accidental
shorts or improper tuning.
The transmitter is in a rain-tight enclosure that permits it to be
mounted out-of-doors at the base of the antenna.
SS-800AVS
Southern Avionics
Company

14.0
(35.56)
I
~
iOOOR
¯ 11.5
’
I 25(TYP)
FRONT VIEW SIDE VIEW
7.0 ~I I_ 3.0
~ (17.78)
-~
. ~-(7.5~)
BOTTOM VIEW
CONDUIT ENTRANCE LOCATIONS
NOTES= I. IN/OUT CONNECTIONS ARE MAOE WITH
FLEXIBLE CONI~JI! THROUGH THE BOTTOM.
2. THIS DRAWING NO. 1471 REV. B .
3. DIMENSIONS IN INCHES (CM).
4l NET. wT. 4SLBS.(2OKGL
TRANSMITTER ENCLOSURE DIMENSIONS
Southern Avionics
Company
SS-800AVS

1.2 Specifications: SS-800AVS
QUALIFICATIONS: Meets applicable requirements of the Federal
Aviation Administration (FAA), Federal Communications Commission
(FCC), and International Civil Aviation Organization (ICAO).
FREQUENCY: 190-625 KHz.
FREQUENCY CONTROL AND STABILITY: Crystal controlled synthesizer.
Rotary dial selection in KHz steps, at integral or half integral
KHz; stability better than 0.005% (-50° to +70°C). Programming
boards are used to cover 190 to 625 KHz in bands of 190-250 KHz,
240-340 KHz, 320-415 KHz, and 415-625 KHz.
TYPE OF EMISSION: AO/A2, A3, AO/A2/A3; Keyed code tone modulation
of an RF carrier. Optional voice modulation of RF carrier,
simultaneous voice and code tone modulation of an RF carrier,
non-simultaneous voice and code tone modulation of an RF carrier.
POWER OUTPUT: 20 to i00 watts continuously adjustable into a 50
ohm load. Power increases during modulation.
MODULATION: Keyed 400 Hz or 1020 Hz tone, International Morse Code,
any combination of up to three letters or numerals, and/or optional
voice modulation. Modulation percentage adjustable from 0-i00
percent. Code modulation percent to 100% with voice signal absent
or to 20% with voice signal present.
BANDWIDTH: 800 or 2040 Hz depending on tone frequency. Up to 6000
Hz for voice transmission.
HARMONIC DISTORTION: All harmonics are more than 63 dB below the
i00 watt carrier, measured at a dummy antenna simulating a SAC Mast
Antenna°
CIRCUIT PROTECTION: Lightning protection on power line and antenna
connection. Circuit breaker in power line. Fuse in power line to
final circuit. Zener protection and fuses on transistors in final
circuit. Special current and voltage limiting circuit on 50V DC
line.
METERING: RF output power, DC current in one of the final transistors,
DC voltmeter, reflected power.
WORKING CONDITIONS: Continuous unattended operation in the following
environments: Ambient temperature, -50° to +70°C; Relative humidity,
0-100%; High salinity as encountered in offshore conditions.
SS-800AVS Southern Avionics 3
Company

AUTOMATIC SHUTDOWN: Transmitter shuts down with loss of tone or
continuous tone, or extreme distortion due to a change in load, or
when power falls below a preset value.
AUDIO LINE INPUT: Balanced, 600 ohms ±20%, -17 dBm nominal. Will
accept -28 dBm to +5 dBm. (0 dBm=l mW into 600 ohms). Audio line
direct current shall not exceed 3 mA DC.
TRANSMITTER AUDIO LINE CONTROL CIRCUITS:
Squ@ich
Allows line input signals to pass through to the modulator
when the line signals exceed the squelch trip point.
Controls code signal modulation level (to 95% with line
signal absent, to 20% with line signal present). Operates
with fast attack, slow decay characteristics. Squelch
level adjustable from -30 dBm to +5 dBm.
AGC
Maintains a constant average modulation level for line
input signals. At maximum sensitivity, AGC stage will
accept input levels of -28 dBm to +5 dBm without modulation
percent change. Attack and decay times adjusted for voice
type line signals.
Over Modulation Control
Limits modulation of carrier to 100% on severe overload
of AGC circuits. Allows clipping of voice signals to
increase average modulation percentage.
INPUT POWER: 115/230 VAC ±20%, 50/60 Hz, 420 VA maximum, or 48
VDC, 5.5 amperes maximum.
EMERGENCY BATTERY SUPPLY (Optional): When emergency batteries are
used, the optional Battery Standby System automatically keeps the
batteries charged when AC power is available, and automatically
switches to batteries on loss of AC power. Four 105 AH deep cycle
(marine type) 12V batteries, such as Gould AP-105, will operate the
transmitter for approximately 13 hours.
INSTALLATION REQUIREMENTS: The transmitter is supplied in a
weatherproof enclosure. The transmitter and the antenna coupler
are suitable for pole mounting out-of-doors.
4
Southern Avionics SS-800AVS
Company