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FEATURED EQUIPMENT

Top: HP 5061A - Cesium Beam Frequency Standard Accuracy: 1 part in 1011 Output Frequencies:  5 MHz, 1 MHz and 100 KHz . 1 Pulse per second (PPS) output for use as an external clock. Primary Power - 115 V AC. Standby power: Internal battery supplies power for approximately 1 hour. Battery Warning Light indicates: (1) Flashes when powered by internal battery,  (2) On when battery is being charged,  (3) Off when charging cycle automatically completed. Bottom: OA/SRC 23 Frequency Standard Group Units:  One CM270/SRC 16 Signal Comparator,             Two  1107/SRC 16 Frequency Standards,             One CY 4029/SRC 23(V) Cabinet Purpose - To supply 100 KHz standard through SB 5091 patch panel and AM 5230 amplifier to various pieces of equipment. Output Frequency - 1 MHz (Test purposes), 100 KHz  Accuracy of Standards - 1 Part in 10^8 . Power - 115 V 400 Hz Single Phase - Primary Power,  28 Volts from BZ 5006 power supply which is powered from 115 V 60 Hz. Secondary Power: 28 V internal battery.     (Image courtesy Canadian Navy)

BZ 5006 Man Aloft and Summary Alarm Panel.  Purpose - provides a summary visible and audible alarm when a fault occurs in one or more of the 7 HF transceivers or 9 VHF/UHF transceivers, 2 frequency standards, or its own internal power supplies. A means of over riding the "fault" indication is provided. Three key operated switches are used to provide the man aloft function for the HF, UHF and for one MF transmitter. The unit operates from 115V AC and is normally left "ON" as it is the emergency power source for the OA/SRC 23 Frequency Standard Group and the AN/URA 64 RF Switching group.  (Image courtesy Canadian Navy)

AN-SIH-503. Provides amplified voice and general alarm signals to various areas of the ship. Has a maximum of 10 control units, 1 test set and a console/equipment cabinet housing 6 amplifiers and 2 power supplies. Image courtesy Canadian Navy)

AN/SIC 503 - INTERIOR COMMUNICATIONS SYSTEM The photo above was taken in a training facility and is meant to only represent a few elements of the system. Refer to the AN/SIC-503 pictorial at the bottom of this document  to see all system components.  Description: Frequency Range - 300 to 4500 Hz  Maximum number of: Stations - 100  Primary power - 440 Volts 60 Hz  Emergency Power - 30.2 V DC Batteries with maximum of 4 hours. Consists of the following units: LS 5012 (A2) - 30 Pushbutton Control Unit, Provides selection of 29 stations: LS 5013 (A2) - 15 Pushbutton Control Unit, Provides selection of 14 stations; Extension Unit (104)  Enables the use of an extra handset/headset; Adapter Unit (105) Provides an interface with LSO's helmet, J 1013 (Junction Box) and AN/SIC 503 system; Secondary Power Distribution Unit (102) (two units) ----------------------------------------------------- Each unit has all the 30.2V DC lines fuzed and distributed to a maximum of 48 stations. Local/Remote switch allows using the other 30.2 V DC supply, Power Conversion Unit (l0l) (two units) ----------------------------------------[ Used as a Battery Charger and a power supply. Power Supply provides 30.2 V DC from an input of 440 V AC; Talk Back Unit (103) --------------------- Used with the Push button control units for two way conversation; Relay Unit (AI)  --------------- One for each LS 5012 and LS 5013 Used in conjunction with the pushbutton control for relay circuits; Primary Power Distribution Unit (two units) -------------------------------------------- Distributes the 30.2 V DC input to the system. J-I0l3 Junction Box --------------------- 60 DB gain amplifier and impedance matching for interfacing microphone/earphone elements with the LSO's Helmet. (Image courtesy Canadian Navy)

AN/SIC-503 - SECONDARY POWER DISTRIBUTION UNIT. Each unit has all the 30.2V DC lines fuzed and distributed to a maximum of 48 stations. Local/Remote switch allows using the other 30.2 V DC supply. Refer to the AN/SIC-503 pictorial to see how this distribution unit fits into the system. (Image courtesy Canadian Navy)

Sony Entertainment System consisting of: (top to bottom) an Allander AM/FM receiver, monitor panel, a Sony stereo cassette tape deck and a McMartin power amplifier. (Image courtesy Canadian Navy)

AN/UIP-501 Public Address Set showing a sample speaker. (Image courtesy Canadian Navy)

UIP-501 Audio Frequency Amplifier. This example can be found at the Marcom Museum in Halifax. (Photo by Jerry Proc)

IC-KAA Intercom. Provides voice communications between vital positions  throughout the ship.  (Photo by Jerry Proc)

AN/PRC-25 . Manpack radio set, 30-76 MHz, 920 channels, 50 KHz channel spacing, Synthesized frequency control. Mode: WBFM. Power: 1-2 watts, solid-state except for the RF power amplifier  vacuum tube. Weight 23 lbs.  The first hand-built operational versions of this set appeared around 1957. (Image courtesy Canadian Navy)

AN/PRC-515. (RT-5047/URC) Portable HF Transceiver. Frequency range 2 to 29 MHz. Modes of operation include USB, LSB, AME, CW and line audio input for data transmission. Power output 20 watts. Note the CW key which can be strapped to the operator's thigh. (Image courtesy Canadian Navy)

The AN/SRD-501 was acknowledged to be a piece of absolute junk by those who used it.

It was a hybrid unit with tubes on the lower deck and solid state on the upper deck (and yes, heat does rise). It was impossible to reach sensitivity or calibration specifications because immediately that the case was opened or closed the ambient temperatures changed and the operating parameters changed. Usually the SRD was never turned off because once it cooled down and then flashed up, it required a complete IF alignment!

No end of "UCRs" (unsatisfactory condition reports) ever brought a resolution to the ensuing problems. The specifications were changed so that a 20 µv sensitivity was acceptable. One technician said "When I was personally responsible for this equipment, I ensured that I got maximum sensitivity and selectivity for 500 kHz and 2182 kHz and hoped it did well for everything in between".
 
 

R5051/SRD-501 DF set. (Image courtesy Canadian Navy)

A detailed list of AN/SRD-501 problems can be found here.
Reference: https://nrc-publications.canada.ca/eng/view/fulltext/?id=1a97eb24-45af-4668-a63d-dd8627547b08

SPECIFICATIONS:

* Frequency range: 60 kHz to 30 MHz
* Modes: AM, FM, FSK, CW, SSB, PPM
* Accuracy:  +/- 1 to 2 degrees with a range up to 70-80 miles on ground wave only.  Not
accurate on sky waves.  Obtaining the sense, (boiling out ambiguity) was difficult above 6 MHz.
This unit contains two receivers and was used by EW personnel to determine the bearing of any transmitting station within its range.
* IF Freq: 500 kHz (which was known to re-radiate).
* Antenna type: AS 5039
 

The AN/SRD-501 was initially fitted to the 205 class ships except Assiniboine. (Graphic courtesy Canadian Navy)

AN/SRN-12

AN/SRN-12 Omega Receiver which was used for obtaining a radionavigation fix from the now defunct Omega system which survived until 1997. Accuracy was +/- 2 nm at distances of 8,000 nm. (Image courtesy Canadian Navy)

LC 204 LORAN RECEIVER

INTERNAV LC 204 LORAN 'C' RECEIVER .  (Image courtesy Canadian Navy)

 

AN/URN-20A (V)1 TACTICAL AIR NAVIGATION

AN/URA-20 TACAN is a polar-coordinate type radio air navigation system that provides an aircrew with distance, bearing and identification information. It can  simultaneously  provide individual  distance  measuring  service  for  up to 100 interrogating aircraft. (Image courtesy Canadian Navy) The signal transmission is a priority sequence and is always done in the following order: 1. AZIMUTH , or a corrected magnetic bearing to the beacon, is a continuous output and services an unlimited number of aircraft. 2. IDENTITY of the beacon, which is transmitted in international Morse Code at  37.5 second intervals with a duration of  5.5 seconds. An unlimited number of aircraft can be serviced. 3. DISTANCE to the beacon in nautical miles, which is done on an interrogation basis, and services 100 aircraft maximum, by selecting the closest 100 aircraft. The distance measuring concept used in TACAN equipment is an outgrowth of radar-ranging techniques; i.e., determining distance by measuring the round-trip travel time of pulsed RF energy. The return signal (echo) of the radiated energy depends on the natural reflection of the radio waves. However, TACAN beacon-transponder facilities, located at specific geographic positions, generate artificial replies rather than depending upon natural reflection. The airborne equipment generates timed interrogation pulse pairs that are received by the surface TACAN system and decoded. After a 50 µsec delay, the transponder responds with a reply. The round trip time is then converted to distance from the TACAN facility by the airborne DME. 4. SQUITTER; a filler pulse train, which automatically keeps the Pulse Repetition Frequency Constant by adding pulses to the train as required.

In  the  X  mode  of  operation,  the  TACAN set transmits on one  of 126 discrete channel  frequencies (which are 1 MHz apart)  from  962 to 1024  MHz  and from 1151 to 1213 MHz. In the Y mode of operation, the  set  transmits on one of 126  discrete  channel frequencies (which are 1 MHz apart) within the range of 1025 to 1150  MHz.  The navigation  set  receiver, operating  in  the  1025 to 1150 MHz  range  for  both the X and Y modes, is always displaced 63 MHz from the transmitter frequency.

Of   the 3,600 pulse pairs-per-second  transmitted by the TACAN,  900 pulse pairs (MAIN and AUXILIARY  bursts) contain the bearing  information; the  remaining  2,700  pulse pairs  are either random noise pulses,  identity pulses, or replies to interrogating aircraft. Once every  30 seconds,  the  interrogation replies and random  noise pulses are interrupted for the transmission of identity pulses. The navigation set has a receiver sensitivity of -92 dBm or better and a nominal peak power output of 3 kilowatts  at  the  transponder cabinet  output.  Power output may limited to less than peak by directives. Since the bearing and identification signals are delivered spontaneously and not in response to interrogations, an unlimited number of properly equipped aircraft can derive this information from the TACAN set over a  line-of-sight  (los) range up to 200 nautical  miles.

AN/URN-20 SPECIFICATIONS

Power Output: 50 watts average; up to 10 KW average peak

Power Requirements:
440V 60 Hz 3 phase for the antenna
440V 60 Hz for the transmitter.
115V 60 Hz for the Low Voltage Power System,  test equipment and blower fans.

Maximum Range : - 200 NM slant range.
Antenna Rotation:- 900 RPM
Pulse Repetition Frequency:  7200 PPS or 3600 PPS
Pulse Spacing: 12 usec
System Delay: 50 usec
Frequency: 962 to 1213 MHz

Klystron Beam Voltage -  neg 20 KV
Klystron Bean Current :   variable 0 to 100 MA, 50 ma optimum setting

Manufacturer: ITT Avionics Division, Nutley. N.J.
Contract Number: NOOO39-68-C-2558
Manual Reference: BRCN 4429(1)
Vintage: believed to be around 1968
 
 

On Canadian ships which were fitted with dome shaped TACAN antenna there were two possibilities for the antenna mounting. 1) It was mounted a pole mast aft of the foremast. 2) In the case of Fraser (shown above), it was fitted atop a lattice tower between the funnels (in 1987). (Photo by Jerry Proc)

 

AS-1747/URN-20(V) antenna internal view. The antenna and pedestal are enclosed in a glass fiber reinforced plastic protective radome. The antenna central array, spin motor, rotating assembly, and bearing control servo assembly are mounted on a single base in the pedestal assembly. This base is maintained in a horizontal plane by a roll servo system. (Image and copy courtesy Combat Index Home Page) Specifications:  Physical Dimensions:  54.5" H;  65 inches diameter Weight: 480 lbs  Operating Temperature -28 C to +95 C  Frequency Range:  Transmit: 962 to 1024 MHz  Receive: 1025 to 1150 MHz  Input Impedance: 50 ohms (nominal)  VSWR > 2:1 over frequency range  Polarization: Vertical  RF Power Rating: 20 kilowatts at 2% duty cycle.  Power Requirement 115 VAC, 60 Hz., 1 phase for convenience outlet. All other power and control voltages are supplied from the amplifier group.  Feed Type: Unbalanced, coaxial cable  Input Connector Type C  Caveat: The cable lengths between the antenna and amplifier group must not exceed 200 feet.

AN/URN-25 TACAN

The AN/URN-25 TACAN Transponder Group is a full service transponder, providing TACAN-equipped aircraft with range, bearing, and identification within a 300 nm radius. This navigation aid was fitted to Annapolis 266 and the 280 class ships. It is currently used in the Halifax class patrol frigates. Pictured above is a dual installation with automatic switchover to the standby unit in case the primary unit fails. In between the transponders is the control unit. (Photo and specifications courtesy NavCom Defence Electronics)

FEATURES:

* All solid state except for the ceramic triode tubes in the transmitter output stage.
* All band capability X and Y mode. 252 channels available.
* Emergency power levels of 700 and 150 watts available in case of transmitter tube failure
 
 

OE273/AS3240 TACAN antenna. Nothing spins in this antenna. All elements are controlled electronically.  (Image courtesy Global Security web page)

SPECIFICATIONS:

Major Units: Transponder Group OX-52/URN-25 and the Control-Indicator C-10363/URN-25

Transmitter: Power output: 3,000 watts at end of tube life.
                                         700 watts reduced power mode  (selectable)
                                         700 and 150 watts for emergency power level.

Antenna Group: OE-273A(V)/URN / AS3240
Power Input: 115 volts 45 Hz to 450 Hz.
Weight:  Transponder - 960 lbs( 436 kg)
              Status Control Indicator - 75 lbs (34 kg)
Dimensions : Transponder Cabinet only  - 66" H x 26" D x 24" W
Manufacturer:  NavCom Defence Electronics. El Monte, California

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SAMPLE BLOCK DIAGRAMS OF VARIOUS SYSTEMS  Click to enlarge
	AN/SIH-503 Main broadcast system as fitted in the ISL class. (Diagram courtesy Canadian Navy)
	Frequency Standard System. This 280/AOR class block diagram shows how the signal from the HP 5061A cesium beam standard is applied to the SRC-23 device as a reference. The outputs of the two 1107 frequency standards are then compared to the cesium beam standard and automatically adjusted.  Two 100 kHz signals then leave the SRC-23 and are applied to the input of the distribution amps. Outputs of the distribution amps are then connected to the SB 5091/SRC patch panel for distribution to the various HF,  VHF and UHF transceivers throughout the ship. (Diagram courtesy Canadian Navy)
	AN/SIC-503 Main Broadcast for a 280 class ship. This pictorial illustrates all of the system components.  (Diagram courtesy Canadian Navy)
	AN/SRC-507 Flight Deck Broadcast System. This was only fitted in ships with helicopters. (Image courtesy Canadian Navy) R5061/ SRC-507 (2 on each ship) ---------------------------------- Battery operated FM receiver enclosed in a helmet. Frequency Range: 132 - 150.8 MHz  Operates at 139.04 MHZ. T5054/SRC-507 (2 on each ship)  Battery operated FM transmitter enclosed in a handset. Can be used. with the fitted antenna or with the AT 1086 whip antenna. Power output 5 milliwatts. Frequency Range: 132 - 150.8 MHZ  Normally operates at 139.04 MHz  AT 1086/SRC 22 (one on each ship)  ------------------------------------- Omni directional whip antenna that may be connected to the T5054 handset. Normally fitted outside just above hangar door. PP 3221/SRC 22 (one on each ship)  ------------------------------------- Battery charger for receiver and transmitter batteries. Holds 20 Batteries. MX5150/SRC-507 (one on each ship)  --------------------------------------- Handset holder for holding two handsets. TS 100A TEST SET ( one on each ship) ----------------------------------------- Used to test the helmet receiver and handset transmitter.

Contributors and Credits:

1) RCN's AOR/TRBL/ISL/265/IRE/MACK Class Equipment Handout. September 1985.
2) Tom Brent <tgb(at)telus.net>
3) TACAN URN-20 info http://tpub.com/content/et/14090/css/14090_39.htm
4) PRC-515 Specs http://www.milspec.ca/radspec/radspec.html#prc515
5) AN/PRC-25 Specs  http://hereford.ampr.org/millist/m7.html
5) PRC-25 info http://www.fernblatt.net/prc25legend.html
6) URN-20 Drawing:  Combat Index  Web pagehttp://www.combatindex.com/hardware/detail/sensor/nav/as-1747.html
7) RCN's NE TECH TQ6B Training Manual
8) NavCom Defence Electronics    http://www.navcom.com/navigation_systems.htm . El Monte, California
9) Electronics Material Officer Course http://www.fas.org/man/dod-101/navy/docs/swos/e1/MOD4LES4.html
10) Global Security Web page  http://www.globalsecurity.org/military/library/policy/navy/nrtc/14090_ch2.pdf
11) Nick England [nick@navy-radio.com]
12) F-5073 Filter

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