Sonobuoy Based Outdoor Intrusion Detectors

Brooke Clarke 2011

ARFBUOY

USQ-42 Receiver

R-1617A/USQ-46 Receiver

TS-2963

ID-1721 Indicator WANTED TO BUY

PP6446A/USQ-46 Power Supply    

During the Vietnam era the "electronic battlefield" (book: Military Communications: A Test for Technology) was developed and it included various outdoor intrusion alarms (my name for these devices).  Some, like the PSR-1 Seismic Intrusion Detector, used wire between the sensors and the main unit and others used a radio transmitter in the sensor and the main unit was a radio receiver.

The frequency spectrum has allocations for different users (see Frequency Allocations).  One band is used by aircraft for communication and navigation (108 to 136 MHz).  A number of Vietnam era outdoor intrusion sensors used this band.

Another band is used for sonobuoy operations by the Navy (162.25 to 173.50 MHz with  31 channels with 375 kHz spacing). This page is about these outdoor intrusion sensors.

Submarines & the Noises they Make

The early work on SOund Navigation And Ranging (Wiki: SONAR), which was named after RAdio Navigation And Ranging (Wiki: RADAR), was done utilizing audio frequencies were an operator would listen on headphones (for those systems that used stereo) or a loudspeaker.  The first sonobuoys also used audio with a human operator listening to the sound.  This is called passive SONAR (code name Jezebel).  There are no pings and whoever is doing the listening is not giving away their presence or position.  When it works it's the preferred method and is by far the most common.  In the 1950s the SOund SUrveillance System (Wiki: SOSUS, my page) which makes use of LOw Frequency Analysis and Recording (LOFAR) rather than the use of human audible sound was put into service.  This worked on snorkeling diesel electric subs (Wiki) and on nuclear powered subs like the Soviet Hotel (Wiki), Echo (Wiki) & November (Wiki) class subs (HEN).

Active SONAR comes in two flavors, the most commonly known is the active ping like in any movie involving submarines.  A ping is sent out and the time measured until it returns.  The early pings were audible to humans, later ultrasonic pings were used and later still the frequency of the ping changed it into a chirp.  If the propagation speed is known the distance to the target can be calculated and with the later types the radial speed of the target can be determined.  The less well known active SONAR method (code name Julie) involves setting off an explosion of a couple of pounds of TNT using either the Mk-15 (Mod-12) or Mk-61 Signal Underwater Sound (SUS).  The explosion generates a spike in the underwater pressure which is similar to a ping at all possible frequencies, it's the most useful type of ping, but can only be used occasionally because it requires a small bomb for each pulse.

Modern  diesel electric subs are very quiet when running on battery power underwater.  The explosive type active SONAR is good at deteting these subs.

The word sono-buoy is based on sound a floating

Sonobuoys (Wiki) have been around since about May 1941 when P. M. S. Blackett, head of the British Admiralty committee for antisubmarine measures, proposed the idea.  In June 1942, the AN/CRT-1 became the first operational sonobuoy, and on July 25, 1942, the first successful launch of a sonobuoy from an aircraft was made from a U.S. Army B-18 bomber. (from: Not Ready for Retirement: The Sonobuoy Approaches Age 65 by Holler, Roger, Horbach, Arthur, McEachern, James).

  They are nomenclatured SSQ-nn.  They are part of anti-submarine warefare (Wiki).

"All sonobuoys currently in inventory are normally launched from standard A-size tubes via pneumatics, free fall, or a Cartridge Actuated Device (CAD).  Shipboard personnel may also launch them by hand or Over the Side (OTS). All are powered by either salt water activated magnesium or silver chloride, lithium chemistry, or thermal batteries and are designed to scuttle at some point after usable or selected life expires."  from Approved Navy Training System Plan, for the Consolidated Sonobuoys.  N88-NTSP-A-50-8910B/A SEPTEMBER 1998

CNU-239/E Shipping Tube 

This may be the standard shipping container for A size sonobuoys.  It's 45" long and an octagon 6-3/4" across the flats.  One end unscrews and when shipping the cap is tapped to the main body.  The weight depends on what model in inside.

Transport Canada SU 0850 makes provision for shipping experimental sonobuoys in this container. But there are limitations: (a) all the dangerous goods are contained within the aluminium body of the experimental sonobuoy described by drawings no. 200896, 200898, 200702, 200671, 200836 and 200837 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defence Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850; (b) the sonobuoy contains a single UN0454 Igniter having a net explosive quantity equal to or less than 0.15 g; (c) the sonobuoy contains a maximum of 2 cylinders of UN1013, Carbon dioxide, each having a capacity equal to or less than 0.120 L; (d) the sonobuoy contains a quantity equal to or less than 40 "C" size lithium batteries that meet the requirement of paragraph (1) of Special Provision 34 of Schedule 2 of the Transportation of Dangerous Goods Regulations; (e) the sonobuoy is packaged in the military performance specification plastic shipping container type CNU-239/E specified in the drawing 012-159-0009-00 deposited by Ultra Electronics Maritime Systems, a division of Ultra Electronics Canada Defence Inc. on Transport Canada's Transport Dangerous Goods Directorate file A 4069-0850;

A Size

Modern sonobuoys have an outside diameter of 4-7/8" (fit 4-15/16" launch tube commonly called 5 inch) and are 1 yard long (36").  The max weight is 39 pounds. 
This is a convient size for one man to handle on a p-3 aircraft.  The larger sizes are not easy to handle.  There are smaller sizes based on getting some interger number of them inside the A size outline.  3 each is called "F" and 2 each is called "G".  The other sizes are pretty much not used in volume.

Hydrophone

A hydrophone (Wiki) is the common sensor for sonobuoys and is typically deployed at 20 meters (65 feet: shallow) or 120 meters ( 328 feet: deep).  A sonobuoy might have 50 depth settings that can be set prior to ejecting it from an aircraft.  This is important because of what's called the thermocline (Wiki) which is where the temperature of the water changes rapidly.  This changes the speed of sound (Wiki).  This causes the sound to change direction just as light will be bent by a change in refractive index (Wiki).  And just like light there's conditions where the bending acts like a mirror and all the sound (or light) is reflected off the layer instead of just changing angles.  So if the hydrophone is on the wrong side of the thermocline it may not hear a sub that's on the other side.

Bathythermograph (Wiki: BT)

This is a device that measures the water temperature as a function of depth.  For example the SSQ-36 might first be dropped and the temperature profile recorded.  Then the ideal depth for the hydrophone determined and programmed into the sonobuoy.  Then the sonobuoys would be dropped.

The speed of sound in water depends on temperature so it slows down as the depth moves from the warm surface to deeper depths, but at some point the pressure caused by deepth will cause it to speed up again.

Service Life

The service life can also be programmed prior to launch for 1, 3 or 8 hours. 

Radio Transmitter

A VHF vertical whip antenna is used.  One feature of this type of antenna is that there's a null directly above the buoy so when an aircraft directly overflys the buoy there's a characteristic signal drop out.  This allows confirming the buoy location.  The 1 Watt transmitter is FM modulated and covers an audio bandwidth of 10 Hz to 20 kHz (about the same as a Hi-Fi system or entertainment FM radio).

Sonobuoy Radio Channels

1st Generation

It appears that the first generation sonobuoys only had 16 channels spaced 0.75 kHz apart between 162.25 and 173.50.  This was probably done using a single crystal in tube type electronics.

2nd Generation

At some point (When?)  the channel spacing was cut in half.  At that time to maintain channel number comparability with the old system, the new channels were added in between the old channels as shown in the table. (chan 1) 162.25 to 173.50 with spacing of 0.375 MHz.
The R-1170 ARR-52A sonobuoy receiver has 31 crystal controlled channels.

3rd Generation

At some point (When?) the total number of channels was increased to 100 (or 99?) by adding channels starting at 136.000 MHz (chan 32) and going to 161.125 (chan 99) with the same 0.375 MHz channel spacing.  Is there a channel 00?
So the band plan in frequency order is,  the new lower frequency channels from 136.000 to 161.125, skipping 161.500 and 161.875 (Why?), then the 2nd generation channels from 162.250 to 173.500 MHz.

USQ-46

The USQ-46 receiver has 3000 channels with a 6.25 kHz channel spacing.   
If the received frequency is below 162.000 MHz then the Freq_MHz = 145.525 + <chan#> * 0.00625,
if the frequency is equal or greater than 162.000 then Freq_MHz = 162.000 + <chan#> * 0.00625.
So there's a strong sonobuoy flavor to how the USQ-46 does channel assignment.
If you know about this, tell me.

Chan	Freq	Chan	Freq	Chan	Freq
1	162.25	6	166.00	11	169.75
17	162.625	22	166.375	27	170.125
2	163.00	7	166.75	12	170.50
18	163.375	23	167.125	28	170.875
3	163.75	8	167.50	13	171.25
19	164.125	24	167.875	29	171.625
4	164.50	9	168.25	14	172.00
20	164.875	25	168.625	30	172.375
5	165.25	10	169.0	15	172.75
21	165.625	26	169.375	31	173.125
				16	173.50

Channel 15 (172.75 MHz)  is used as an emergency search and rescue frequency.

Command Function Select (CFS)

The aircraft can transmit to the sonobuoy to change the commands while it's in the water which is much better than the old way of making the command decisions prior to launch.
The UHF frequencies used for this are: 282.900, 291.300, 291.400, 291.500 MHz

DIrectional Frequency Analysis & Recording type acoustic sensor (DIFAR)

DIFAR Patents

3987404 Underwater Direction Finding System, Sanders, (filed: Nov 3 1967) Issued: Oct 19, 1976, 367/3; 367/125; 367/126 - "An underwater direction finding system includes a pair of directional hydrophones and a compass in a novel arrangement which associates the signals from all three elements with a single subcarrier.  Subsequent demodulation of the subcarrier signals in an airplane or ship then provides directional information directly referrenced to the earth's magnetic coordinates." Calls: US2754493 Indicator for Sound Direction Finder Feb 4, 1955 1956 LIPPEL US2837730 Deflection Method for CRT Aug 4, 1952 Jun 3, 1958 IAUAEM US2867788 Object Locating Systems (sub hunting) Feb 27, 1943 Jan 6, 1959 HARRY US3022462 Frequency Modulation Detector System (see below) Jan 19, 1953 Feb 20, 1962 FREQUENCY MODULATION DETECTOR SYSTEM US3148351 Directional Hydrophone System (see below) Jun 12, 1961 Sep 8, 1964 FILTER US3160850 Underwater Locating Apparatus (Glomar Expolrer?) Dec 27, 1960 Dec 8, 1964 DUDLEY US3176262 Directional Sonar Systems (dipping SONAR) Apr 6, 1960 Mar 30, 1965 EHRLICH ETAL, DIRECTIONAL SONAR SYSTEMS Referenced by: US4872146 May 23, 1988 Oct 3, 1989 Canadian Patents & Development Limited Method and apparatus for simulating phase coherent signal reflections in media containing randomly distributed targets US4879694 Mar 4, 1988 Nov 7, 1989 Rockwell International Corporation Difar demultiplexer circuit US5253223 Apr 27, 1992 Oct 12, 1993 Den Norske Stats Oljeselskap A.S. Seismic device US5265066 Apr 27, 1992 Nov 23, 1993 Den norske stats oljeselskap a.s Seismic cable US5442590 Apr 27, 1992 Aug 15, 1995 Den norske stats oljeselskap a.s Seismic cable device US6108270 Jul 6, 1999 Aug 22, 2000 Torpedo seeker head having directional detection independent of frequency US6622647 Jun 26, 2001 Sep 23, 2003 Active noise cancellation for a torpedo seeker head US8059485 Jun 4, 2008 Nov 15, 2011 NEC Corporation Communication system, information collecting method and base station apparatus

Reserve Batteries

Sonobuoys

Naval Consolidated Sonobuoys @FAS -

	Func	Start	End	Links
AN/CRT-1	5 vacuum tubes single channel FM	Jun 1942
AN/CRT-4	RDRH	Feb 1943
AN/CRT-1A	6 channels	1944
AN/SSQ-1	upgraded CRT-4	not UK SSQ-20
SSQ-2			15 Feb 1955	jproc
1950 start of: Sound Surveillance System (SOSUS)
SSQ-20		1951
SSQ-2B	Julie explosive	1956
AN/SSQ-15	Julie RO B-size
SSQ-23	Julie	1956	19 Nov 1964
SSQ-28	Jezebel-LOFAR	1960	19 Nov 1964
SSQ-36	BT The BT sonobuoy is an expendable thermal gradient measurement sonobuoy that operates on one of three or one of 99 Radio Frequency (RF) channels. It consists of a thermistor temperature probe that descends through the bottom of the sonobuoy canister producing a continuous reading of temperature versus depth. The thermistor temperature probe will descend to 1000, 2000, or 2625 feet, depending upon the sonobuoy selected. Fig 36-01 Tubes Ship: 7" x 45" Launch: 5-3/8" x 39-1/4" Housing: 4-3/4" x 35-7/8" Fig 36-02 Launch Tube Cap - twist and lift. Fig 36-03 Housing (what drops through air and lands in ocean
SSQ-38	30day omni-directional LOFAR (replaced SSQ-28) 10 to 6,000 Hz 31 chan	1964	1 June 1961
SSQ-41	single hydrophone	1964
SSQ-47	(replaced Julie explosive system) active ping omni directional range only replaced by SSQ-50	1968
SSQ-48	replacedd by SSQ-41B		26 Feb 1981
SSQ-50	CASS
SSQ-53	31 RF Channels 10 Hz - 2.4 kHz 90 feet fixed depth		Sep 1967
SSQ-53A	90 or 1000' depth 1 or 8 hours
SSQ-53B	DIFAR fitted with microprocessor controlled EFS capabilities, with three depth selections [100, 400 or 1000 feet], three operating time selections of 1, 3 or 8 hours, 99 vhf channels. Operation Before inserting the launch tube into the aircraft chute the sonobuoy is programmed for operational life, channel number and depth by using the SET button.  If done incorrectly pulling the TEST plug for a few seconds will allow reprogramming.  Power for this comes from a couple of coin cell batteries.  The correct programming can be confirmed by pressing and holding the VERIFY button for a couple of seconds. When forced from the aircraft chute by means of compressed air the lid is blown off the launch tube deploying the parachute on the metal sonobuoy housing.  The plastic launch tube stays in the chute. When the metal sonobuoy (Fig 53-8)  impacts the water is starts to sink and water activates the reserve battery.  As soon as the battery has power (probably within a few seconds) the squib retaining the large spring allows an arm to puncture a compressed gas bottle inflating the buoy/antenna (Fig 53-17).  At the same time, depending on the programmed depth one or both rods (Fig 53-21) are driven down to set the amount of cable that will unspool controlling depth of the sensor.  A very short time later the three main components of the sonobuoy are separated as the metal outer housing is blown clear and sinks. With power the radio transmitter begins to send it's signal. The duration may be determined by a simple electric timer that shuts off the transmitter after the programmed time, or . . .  there may be some provision to do more? Although very old I believe this unit would still work. Fig 53-1 Launch Tube 5-3/8" diz x 39-5/8" long dated 5/87 - it's 12/11 now so this is just under 25 years old. The shipping container probably was left on the ground. If you know the deployment sequence let me know what it is. Fig 53-2 Top: Channel (01 to 99), Duration (1, 3 or 8 hrs), Depth (90, 400 or 1000) Ft., Verify What was a transparent membrane has aged and is falling apart.  When intact would provide a moisture barrier so the decissant  could keep the inside dry. Fig 53-3 Sonobuoy Launch Container LAU/126A NOO 83-86-C-0007 .OT 036 Fig 53-4 LAU/126A Launch Container Cap Fig 53-5 Cap Off by removing 4 black plastic clips It's not clear how the sonobuoy was programmed and in what order loaded into the aircraft launch chute. Fig 53-6 Inside the Launch Tube, marked: Caution: - Disengage before launch Caution: Spring Loaded Fig 53-7 SSQ-53B Ready to launch (string holding spring snare) The metal SSQ-53B housing is 4-3/4" O.D. The label just to the right of the depth scale says: WARNING Remove Plug Prior to Test EFS Battery may be damaged if pins 1 and 2  are shorted or voltage is applied across pins 1 and 2. Voltage applied to pin 3 may cause high velocity ejection of top plate. Reinstall plug before use. Fig 53-8 With parachute deployed The gray plastic cap was pryed off instead of sumerging in water and disolving the two metal links? Fig 53-9 There are three functional parts.  The right is the antenna-buoy cover and receiver/transmitter, the center iscable spools and the bottom (left) is the sensor. Fig 53-10 Three Major Components: Left: Radio, Antenna, Battery Center: cable Right: Sensor Fig 53-11 Sensor, marked: Sparton Corporation 120-0127-002 Clock Number: 0358     Date 06/03/87 {bar code] SIN: -67.1 db    COS: -68.4 db      OMNI: -72.1 db the latter three parameters are related to the DIFAR aspect of the sensor. The black cylinder hanging out the bottom is probably the omni hydrophone. Note:  There's a single green/white wire (cable) going to/coming from the sensor. I expect it's a small coax cable, but it remains to be seen. Fig 53-12  Radio Buoy Fig 53-13 With cap pulled off and buoy opened, but not inflated. There appears to be small wire antenna with a resistor at the top. Fig 53-14  Test Socket & Memory Battery Test Socket cap held by O-Ring, need big pliers to pull/twist it out. There was a jumper plug  in the socket, more later. Memory Battery and PCBs There's a big spring that can puncture what's probably a good size CO2 cylinder in order to inflate the buoy/antenna.  There's what looks like a fusable link holding the spring in tension that could trigger the gas. Also at the bottom of the PCB chamber there are a couple of lever arms that have a resistor wrapped around their ends.  If the resistor was exploded (over powered) then it would release these arms to do something (maybe control the depth through the cable spools? The two coin cells are in the white plastic holder.  They provide about 6 Volts and are still good. On the left board there are three red wires (Battery +), a bare stub where I wiggled off the battery + wire, and a yellow wire (to socket pin 3).  The bare wire at the top (just under the coin cells) that's soldered to a lug on the central metal plate is ground (same as the cast metal frame where the battery- wire connects.). Fig 53-16 Fig 53-17 Main Battery held to cylinder with double sided foam tape. 1 lb 11 oz. 4-1/4" hi x 3-1/8" w x 2-9/16" d (11 x 8 x 6 cm) There is a hole on two sides just under the top cover to allow water to enter. This is a water activated reserve battery. Fig 53-18 In the other photos you can see green deposits on the inside of the radio/buoy black plastic.  I think that's because this reserve battery contains Copper in a form that allows it to escape.  This may be a limiting factor for the shelf life.  The Copper deposits are probably the result of the failure of the moisture proof membrane the covers the programming push button switches.   Once the moisture in the air gets to the reserve battery it's going to become a carrier for the copper and also will lower the battery capacity. Idea:  Rather than depend on the moisture proof membrane (and decisant) to keep the reserve battery fresh, it should be in a compartment that's sealed until the metal housing is seperated from the launch tube.. The two coin cells are still good after almost 25 years since this was manufactured.  Fig 53-19  High Pressure Gas bottle to inflate buoy/antenna There are three PCBs: Blue: modulator & RF exciter Green:  I/O panel Tan: RF Power Amp Fig 53-20 Test Socket Message Socket Pin Ohms to Gnd Ohms to Bat+ Plug 1 1M8 1M8 1-7 2 876k 1M4 3Note1 >1M 0.2 3-4 4 0.2 405k 3-4 5 1M 1M 6 1M 1M 7 0.1 405k 1-7 Note 1: pin 3 is connected to one side of the squib that can cut the lanyard holding the arm that will puncture the high pressure gas for deploying the buoy/antenna. Pins 7 & 4 are connected to the ground bulckhead (0.0 Ohms). Pin 3 is connected to the red battery wire (0.0 Ohms) The jumper plug connects: 1 to 7 3 to 4 With the jumper plutg removed: Red test lead to red battery wire (black lead to ground) = 1M00 Ohms Black tet lead to red battery wire (red lead to ground) = 401k Ohms Pin 1 is connected to the negative (black wire) leading from the two stacked coin cells). The jumper plug connects pin 1 to pin 7.  Pin 7 is connected to the micro controller.  So these two pins relate to zeroing the programming. If you have information on how the test socket is used please let me know. Fig 53-32 Test Socket Schematic See Fig 55-29 & Fig 53-31 for photo of Fuse 1 (LE  1A) A few of possible reasons for placing a fuse directly across the reserve battery.  One or more of them might be the reason. For Now I'll just remove the fuse. 1) Shorting the main power supply protects the squibs are from being     fired by static or electromagnetic fields (like high power transmitters on board ships). 2) The reserve battery may like activate better when heavily loaded.  Note:  The      BA-4386 Magnesium battery needs to see a heavy load in order to fully activate. 3) When the fuse blows the battery is delivering at least 1 amp and that surge current      would next go to blowing the squibs.  This might be more reliable than ramping up      the squib voltage. Pins 5 & 6 each connect to one of the pins on the micro controller.  The Test plug (cable) probably has a jumper between pins 1 & 7 to connect the EFS (coin cell) battery thus powering the micro controller, and when it's powered up the test socket pins 5 & 6 can be used.  But for what?  Data In/Out, firmware programming, verification check sum, something to do with the hard wired option jumper to the upper right of the LCD housing? let me know.  Fig 53-21 Buttons (now working) maybe because of cyclying the plug. Pressing and holding Verify for a couple of seconds will show the function settings. To change the settings the plug must be removed for a few seconds. Pressing SET starts the channel number counting 0 to 9 to 0. Pressing SET fixes the tens digit and the units start counting pressing set fixes the channel number and the life bars start cycling.  Pressing SET sets the life and then the depth bars start cycling, pressing SET fixes the depth.  Now pressing Verify for a few seconds will display the function settings. They were set for: 1 hr, chan 63 & 1000' Now set for 3 hrs, chan 54 and 400'.   Fig 53-22 EFS LCD (plug shown installed) Fig 53-23 Depth Selection The two levers are either in the position shown or they are pushed toward the center to select how much cable is deployed.  The selection is made by the two blue plastic actuators using a push (or pull) of the rod with the spring.  Note this rod is smooth and would not support a rotary motion.  Also the two levers in the bottom of the radio compartment work in an up or down fashion, not in a rotary fashion.  See Fig 53-9 and a close up from it Fig 53-22 below.. Fig 53-24 Close up photo of depth selection blue plastic parts. Fig 53-25 Cutting Squib Wires Three red wires have been cut deactivating the three squibs so DC power can be applied. Test Socket Resistance readings after cutting the wires: Pin Ohm to Gnd Ohms to Bat + Plug 1 1M9 OL 1-7 2 860K OL 3 >1M 1.9 3-4 4 0.6 >1M 3-4 5 1M0 1M3 6 1M0 1M6 7 0.5 1.9 1-7 Gnd to Batt+ (w/0 Plug) = 1M0 Gnd to Batt+ (w Plug) =  0.7 There is still a dead short across the battery terminals! pin3 is yellow wire to Battery + terminal (and red wires) pin 4 is the metal frame (battery -) the black battery wire with the internal tooth lug. This is confusing. The hi pres gas squib is 36.2 Ohms. One of the depth squibs is 18.5 Ohms (red to violet) not to ground. The other depth squib is 18.3 Ohms (red to blue( not to ground. These may be 1/8 Watt 18 Ohm resistors. Rated power would be at 1.5 Volts, 10X power at 4.7V, 100X power at 15 Volts, so if the battery is about 15 volts the resistors would fail mechanically. Note the plug must be installed for the progrmming to work, so operation without the plug is not an option.   The plug has a jumper between pins 3 and 4 that is part of the path shorting the battery + and - terminals. The coax feeding the antenna reads 42.7 Ohms.(resistor is Yel-Org-Blk-Red Fig 53-26 Green Cable 10K0 Ohms either polarity. This joint is located on the black plastic bottom plate of the Transmitter section. White to White, Green to Green. See: Fig 53-10 and Fig 53-12. How to take apart the transmitter?  It may be possible to push everything out the bottom, but that would break the two push button switches.  Probably the best way is to saw from top to bottom at two places 180 degrees apart. Fig 53-27 The switch buttons are mechanical working through a rubber boot and can be pulled out of the plastic housing. After letting the top sit overnight after applying some Kroil to the joint between the plastic housing and the metal plate with 0_ring seal the assembly pressed out the bottom easily.  It was necessary to unsolder the antenna cable and the green wire to isolate the top section. Fig 53-28 RF Amplifier Tan PCB from top section The antenna was connected at the top of this board where the notch is. Gnd to the left and center to the right of the notch. This is probably the Tx power amplifier and antenna matching/filtering board. Fig 53-29  Command and Control Board Green PCB from top section. This is the digital board. I doubt the micro controller is doing anything with the sensor data, so it's probably running at a very slow clock frequency to conserve power. So there's no need for a crystal for it. There are three 2N6724 2 Watt NPN Darlington transistors just to the left of the push buttons used for firing the three squibs.  The collectors go to the squibs and all three emitters are connected to the bulkhead ground plate. Top: RF Amp board depth squib Center: Synth board depth squib Bottom: CO2 Maybe the transistor that blows the antenna squib is on the RF amp board? Above the upper right corner of the black plastic LCD housing thre is a row of 6 holes and a jumper is installed in the right most of these.   What option is this selecting?  Let me know. Fig 53-30  Synthesizer and Modulator Board Blue PCB from top section. This board interfaces with the sensor package. The crystal at the lower left is marked: 10.2985 MHz.  This is a non standard value, see my Crystals web page. Maybe related to the DIFAR spectrum. This board seems to be mostly analog in nature. On the bulkhead plate at the bottom there are the two depth programming levers. As shown the squibs (resistors) are intact and the lever is held in the down position. The two rods are spring loaded and trying to lift up.  When the squibs are broken the depth programming rods are forced up by their spring. At the bottom right the green/white sensor cable can bee seen coming through a hole and connectionto two pads. All three squibs measure 500K Ohms to Bat+ and open to Ground.  So they are not causing the dead battery short. The data codes on the ICs are 1984, 1985 & 1987. 6 Jan 2012 - New Idea about the direct battery short. The short may be part of a Safe And Arm system that would prevent the buoy from becoming active prior to an actual launch.  This may be a common system used not only on sonobuoys but also things like countermeasures equipment like flares and chaff dispensers. If that's the case then something about the pneumatic launch would disable the short. Fig 53-31  Fuse on digital PCB This appears to be the cause of the dead short across the reserve battery terminals. Power Up (with sensor disconnected, antenna attached) For about 15 seconds the current is in the 30 ma range then jumps up to150 to 200 ma when the transmitter turns on. After battery power the Verify button does not work. The battery voltage appears on the green/white cable. On reconnecting the green cable between the floating buoy and the sensor. Buoy The resistance between the two wires and ground is: left: 1M and right 10k. The resistance between the two wires and Batt+  is: left: 0.2  and right  1M Sensor The resistnace between either wire and the sensor metal is an open circuit. So as of 12 Jan 2012 it's still not clear how to be sure the polarity is correct to reconnect the sensor. Thanks to Ugo in Italy there are two conductors in the cable, one supplies power to the sensor package (which has input filter caps) and the other is the audio signal to be modulated onto the transmitter.  Seawater forms a ground return between the floating transmitter and the sensor.  This is confirmed by the book The Ears of Air ASW. pg 241.		1984
SSQ-53D	Dwarf "G" size version of the B	1991
SSQ-53D	DIFAR only sensor, 90, 400 or 1000 feet, no CFS -53D(2) 5 Hz - 2.4 kHz 1/2, 1, 2, 4 or 8 hours -53D(3) sea state 6	2003
SSQ-53E	Digital version Additional hydrophone @ 45' for CSO CFS 100, 200, 400 or 1000 feet AGC 91.44 cm long
SSQ-53F	DIFAR, CSO made by combining the 305 cm long SSQ-53E & SSQ-57 NSN 5845-01-475-9870 adds CO hydrophone with directional units (replaces SSQ-57) CFS Rx - single channel UHF Tx - 96 selectable frequencies (136 - 173.5 MHz), 1W 90, 200, 400, 1000 Ft.	2000
SSQ-57	Calibrated-LOFAR 10 to 10,000 Hz	1972
SSQ-62	DICASS FM sweeps	1976
SSQ-62C	99 channels	1993
SSQ-62E	Command Function Select   Electronic Function Select 96 chan 136.000 - 173.500 MHz CW Out: 6.5, 7.5, 8.5 or 9.5 kHz			Sonobuoy Tech Systems
SSQ-77A	VLAD	1981
SSQ-77B	" more hydrophones, 2 depths, 2 beams	1989
SSQ-77C	" adds RF command function selection
SSQ-86	DLC
SSQ-101	ADAR	FY97
SSQ-110	EER		30 July 1997
SSQ-125	advanced EER ADLFP sound source used with: ADAR sonobuoys like SSQ-53F, SSQ-77C and SSQ-101
SSQ-536	BT
SSQ-801	BARRA
SSQ-906	LOFAR Omni
SSQ-926	ALFEA, GPS
SSQ-937	BT
SSQ-954	DIFAR
SSQ-955	HIDAR
SSQ-963D	CAMBS			Janes
SSQ-981	BARRA

ADAR: Advanced Deplorable Acoustic Receiver
ADLFP: Advanced  Deplorable Low Frequency Projector
ALFEA: Active Low Frequency Electro-Acoustic
BARRA: means Listening in an indigenous Australian language - The Barra Sonobuoy System, Barra Sonobuoy Design, horizontal array
BT: Bathythermograph
CAMBS: Command Activated Multi-Beam Sonobuoy
CASS: Command Activated Sonobuoy System
CFS: Command Function Select (set function with 2-way radio when buoy is in water)
CO: Calibrated Omni type acoustic sensor (5 - 20 kHz)
CSO: Constant Shallow Omni type acoustic sensor (30 - 5000 Hz)
DICASS Directional Command Activated Sonobuoy System
DIFAR: DIrectional Frequency Analysis & Recording type acoustic sensor (5 - 2400 Hz)
EER: Extended Echo Ranging
EFS: Electronic Function Selector (RF Chan, Life, Depth, Sensor type, AGC)
HIDAR: High Dynamic Range DIFAR
LOFAR: LOw Frequency Analysis & Recording
RDRH: Rotating Directional Receiving Hydrophone
REFS: optical Remote Electronic Function Select (either while in launch tube (easy) or in water (requires laser))
RO: Range Only
SUS: Signal Underwater Sound (MK-84 MOD 1 SUS uses 3.3 and 3.5 kHz audio to generate 5 codes as messages to a sub.)
VLAD: Vertical Line Array Detector

An Aircraft Control Panel

	Control Drift - Compute - Reset PDI: BDHI: Marker 1 to 6, GTP: Marker 1 to 6  Insert ASA-20 or AQA-1                                                        ASA-20 or AQA-1                                                   A-B: 1 to 6 Computer Ellipse                    A: Off to 6                   Data Release                B: Off to 6
ASA-31 Julie Control Panel

ASA-20 Sonobuoy Recorder "Jezebel".

The AQA-5 is a 4 channel paper chart recorder.
Youtube video: AN/AQA-5 Acoustic Charts Recorder
P-3 Orion Aircraft - Walk Around -

BDHI: Bearing Distance Heading Indicator
PDI: Pulse Doppler Illuminator
3582871 Ellipictal Computer System, Morris Snyder (Navy), Jun 1, 1971, 367/3; 367/107; 701/300; 708/801 - determines sub position using sonobuoys

AN/ARR-502 Multichannel Sonobuoy Receiver (data sheet, data sheet)

Since the sonobuoy has a cylindrical ( 4-4/7" O.D.) shape it makes sense to have the electronics in the form of cylindrical modules that can be stacked end to end. These modules are about 2-3/4" O.D. and have a circular connector around the outer edge.  For use as an outdoor intrusion detector the hydrophone is replaced with a geophone (Wiki), or other sensor like used to listen for the RF generated from spark ignition engines.

1^st Generation

I think this outdoor intrusion sensor was made by modifying a sonobuoy.  The Automatic Radio Frequency Buoy (ARFBUOY) may be this unit or something very similar.
See Popular Mechanics March 1976 "War watch in the Sinai" references the "electronic battlefield" aka the "McNamara Line".   Mentions sensors:

• MAGID - Magnetic Intrusion Detector can discriminate between T-48 and T-60 tank or between 2-1/2 Ton and 5 Ton truck.
• Noiseless Button Bomblet (NBB) - a transmitter triggered my the slightest movement
• T-4 - senses RF from vehicle ignition systems.
• MINISID III - combines a geophone with another sensor (an IR beam breaker for example) and does not transmit an alarm until both sensors are being triggered.
  

See the web page:  http://1stwave553rdreconwing.com/AboutUs.html
and/or search on keywords: John T. Correll, Igloo White, the McNamara Line,
AF Magazine Nov 2004 - Igloo White the quotes below are from this article.

Spikebuoy - seismic sensor

ADSID

Acoubuoy - microphone

Arfbuoy - repeater

Photos courtesy of Dennis Starks

ARFBUOY Acoubuoy This is an 18 pound steel cylindeer 4-3/4"x22". It's designed to be air dropped  with a drag chute and get hung up in the trees.  There is a central tape whip and four ground plane tape whips each 17" long. which is a quarter wave at about 190 MHz.
The central gold colored thing is the microphone.  Note all the holes in the front to let sound it and protrct the microphone from tree limbs.
	Battery This is a battery type I don't recognize.  If you know about it please let me know what it is.	Sound Observer (Locator) Remote Microphone. It's identical to the mike in the acoubuoy. This is the same mike that's in the photo at left with the question mark.  The 5 socket connector is marked: 7004 Deutsh DBA36-10-5SN-10-6032 The contacts are numbered 1, 2, 3, 4 (but no 5). There's a knurled and slotted screw head on the back that can be unscrewed about 1 turn, maybe to normalizing the pressure inside to match atmospheric. See RT-1185 for a similar application.

USQ-42 Receiver

R-1617A/USQ-46 Receiver

TS-2963 Test Set (Transmitter)

PP-6446A/USQ-46 Power Supply (Receiver, Test Set)

GSQ-154

GSQ-160

2422337 Submarine Detecting Buoy, C. Chilowsky, Jun 17 1947, 367/4; 441/11; 441/25; 441/26; 441/28; 455/99 -
2817909 Taining Device for Operators of Underwater Detection Appratus, B.M. Taylor, et al, Dec 31 1957, 434/9; 434/10
2465696 Method and Means for Surveying Geological Formations, LeCoy C Paslay, Mar 29 1949, 367/23; 114/245; 346/33.00C; 367/16; 367/20; 367/155 -
2641751 Hydrophone Casing, (Navy),  367/173, Jun 1953 -
2644243 Control Compass, (Navy), 361/280; 33/363.00Q, Jul 1953 -
2749436 Sonobuoy, R.H. Rines et al, Jun 5 1956, 455/99; 342/6; 367/3; 455/91; 455/107; 455/116; 455/129 -
2828475 Remote Control or Measurement Indicating Means, (Navy),  Mar 19 1958

3022448 Modular subassembly, Feb 1962
3281765 Minature Sonobuoy and Cable (ITT), Oct 25, 1966 - small dia (0.030") cable which acts as a spring, Ni-Cad batt charged prior to use.
3290642 Directional Sonobuoy, (Navy), Dec 6, 1966,  367/4; 367/120; 367/129; 441/33 - weight driven rotating sensors

3309649 Sonobuoy with Depth Selection Capabilities, Sanders Assoc, Mar 14 1967, 367/4; 441/33 -
3460058 Radio Sonobuoy, (ITT), Aug 5, 1969, 367/4 - operates below thermocline
3671928 Automatically energizable Sonobuoy, Aquatronics, Jun 20 1972, 367/4; 441/11; 441/33 - some similarity to acoubuoy.
3720909 Directional Hydrophone System, Spartan Corp, Mar 13 1973, 367/173 - seismic sensors in sonobuoy
3786403 Underwater Acoustical Detection, Navy, Jan 1, 1974, 367/4; 441/25; 441/26 - SIDECAR,
3921120 Float Actuated Release Mechanism, Sparton Corp., Nov 18 1975, 367/4; 116/209; 441/33 -
3944964 Air Dripped Linear Acoustic Detector, (Navy), Mar 16, 1976,  367/4 -
3991475 Depth selecting spool device, Navy, Nov 16, 1976, 116/209; 367/4; 441/24 -
4096598 Selected Depth Mooring System, R.J. Mason, 441/25, Jun 1978 -
4114137 Directional Sonobuoy, (Navy), 367/171; 441/1; 441/28, Sep 12 1978
4186370 Stabilized sonobuoy suspension, Raytheon, Jan 29, 1980, 367/4; 367/130; 441/11; 441/33 -
4189786 Radio Buoy Assembly, R.E. Adler, Feb 19 1980, 367/4; 367/5; 367/133 -
4357688 Low cost sonobuoy, Navy, Nov 2, 1982, 367/4; 367/173 -
4358834 Self-deploying Buoy System, Navy, Nov 9, 1982, 367/4; 367/173 -

4493664 Sonobuoy Float Inflation and Depth Selection Initiators, Navy, Jan 15, 1985,  441/7; 222/5; 367/4; 441/26; 441/30; 441/33 -
4530269 Remotly Initiated Speration Latch Assembly, Burroughs Corp, Jul 23 1985, 89/1.14; 102/293; 102/378; 220/261; 367/4; 367/173; 403/2 - electrical match for seperation

4590590 Sonobuoy Multiple Depth Deployment Apparatus, Magnavox, May 20 1986, 367/4; 441/25; 441/33 -
4727520 Cable Deployment Unit, Sparton of Canada, Feb 23, 1988, 367/4; 367/3; 441/25 -
4901288 Compact cylindrical sonobuoy, Sparton Corp, Feb 13 1990, 367/4 -
4924445 Sonobuoy Cable Pack, Royal Navy, May 8, 1990, 367/4; 114/326; 367/3; 441/8 -
4927057 Autiomatic Inflator for Inflatable Articles, Inflation Tech, May 22, 1990, 222/5; 222/23; 222/41; 222/52; 222/63; 222/93; 222/94; 441/93 -
5076468 Squib Inflator Adapter, Halkey-Roberts Corp, Dec 31, 1991, 222/5; 222/91; 441/93 -
5197036 Sonar Array Mounting for Sonobuoy, Mar 23, 1993, 367/4; 367/153 -
6400645 Sonobuoy Apparatus, (Navy), Jun 4, 2002, 367/4; 367/3; 367/153 - opens sort of like an 8-sided umbrella

SONAR
4998224 System for providing improved reverberation limited sonar performance, Mar 5, 1991
5138587 Harbor Approach- Defense Embedded System, (Navy), 367/136, Aug 1992
5144487 Expendable moving echo radiator, (Navy),  367/1; 367/137; 367/165, Sep 1992 - countermeasures equip
5808580 Radar/sonar system concept for extended range-doppler coverage,
6018493 Sonar Suspension Apparatus, Dowty Maritime Sys, Jan 25, 2000,  367/16; 367/20; 367/153; 367/155; 367/165; 441/33 -

Launching

Photo from Wiki Sonobuoy page

From Ships and Aircraft of the U.S. Fleet (2005):
The p-3C Orion. . .  tail-mounted ASQ-81 Magnetic Anomaly Detector (MAD) and 48 external (fuselage) sonolbuoy chutes and four in-flight reloadable(internal) chutes; a total of 84 buoys normally are carried.

2707904 Sonobuoy Dispensers, Breeze Corp, May 10, 1955, 89/1.51; 367/3 - revolver,
3451306 Safe and Arm Ejection System, Susquehanna Corp, Jun 24 1969, 89/1.1; 89/1.51; 102/259; 102/357 -
3905291 Cartridge-actuated Device and Launching Assembly using same, G.T. Corbin, Sep 16 1975, 102/430; 42/96 -
4026188 Modular Buoy System, Sandars Assoc, May 31 1977, 89/1.51; 102/351; 102/352; 102/354; 102/406 -
4263835 Sonobuoy Launcher System, Navy, Apr 28, 1981, 89/1.51; 89/1.3; 89/1.806; 89/1.818 - bouys loaded from outside

4397433 Revolving-cylinder jettison device for transporting and releasing buoys on and from Aircraft, , Aug 9 1983, 244/137.4; 89/1.51; 89/1.801; 244/118.1 -
5052270 Multi-sonobuoy launch container with constant force spring, Navy, Oct 1 1991, 89/1.51; 244/137.4 -
7278416 Pneumatic projectile launcher and sonobuoy launcher adaptor, Lockheed-Martin, Oct 9, 2007, 124/72; 89/1.51 -

Reserve Battery

A reserve battery is one where the electrolyte is stored seperated from the electrodes.  They can sit for decades and when activated (heat, water, gas, mechanical force) are then a battery.

2590584 Sea Water Battery, Bel Tel Labs, Mar 25 1952, 429/119; 429/152; 429/231.6 - silver chloride on silver & magnesium electrodes in salt water.
2669596 Reserve Battery Enclosure, Navy, Feb 16 1954, 429/8; 116/1; 429/119 -
2699461 Defered Action Battery, Burgess, Jan 11 1955, 429/119; 429/152; 429/162 -
2715652 Electric Battery for Airborne Equipment, Eagle-Picher Co, Aub 16 1955, 429/118; 429/152; 429/162 : -40 to 160 def F operation
3178316 Reserve Battery, Servel Inc, Apr 13, 1965, 429/119; 429/130; 429/210 -
3767933 Power Supply having a Plurality of Power Sources that are Swquentially Placed on the Load One at a Time, Oct 23 1973 307/48; 307/66 -
3966497 Seawater Battery, ESB Inc, Jun 29 1976, 429/119 -
4601961 Bilaminar Seawater Battery, Navy, Jul 22, 1986, 429/119; 429/127 -
5395707 Environmentally safe water-activated battery, ACR Elec, Mar 7 1995, 429/119; 429/128; 429/130 -

Got this from Fair Radio.  It consists of a bladder just under five feet long and about three inches in diameter filled with mineral oil (or something similar).  Inside there are eight cylindrical  Rochelle Salt Crystal doublets, each about three inches long with about a three inch gap between sensors (series or parallel connection?). 

In the Combat Information Center magazine for July 1944 (Vol. 1 No. 5) there's an article on harbor defense that mentions both a sonobuoy with vertical hydrophone array (radio has 12 mile range and hydrophone has 1,000 yard range) as well as multiple hydrophones laid on the bottom and connected to multi-conductor cable.

At the cable end a matching transformer with 25 Ohm output impedance.  Frequency response of 1Hz to 20 kHz.
The internal construction seems to be steel cylinders spot welded to two steel rods that tie them toghther.  The crystals are glued into the cylinders and wired in parallel.
If buried in the ground as is the mineral oil will leak out leaving air voids.  If repackaged in a PVC pipe the sound would travel up and down the pipe wall which doesn't happen with the current rubber bladder.  So maybe some type of flexable hose would be a good replacement? 

The idea is to bury it and have excellent low frequency (below 20 Hz) response.  The Infra sound sensors use garden hose with a pin hole leak.

Official Description:

Hydrophone, U. S. Navy Harbor Detection, Sonic, NT-51038F; P/O type JR-1 Harbor Detection Equipment. Sensitive listening, frequency range 1 - 20 thousand cycles per second; with 8 Rochelle Salt Crystal Doublets each approx. 3" x 2" x 1", in metal frame w/matching transformer to 25 ohm line, in Castor (?) Oil, encased by heavy rubber jacket 56" long x 2 1/2" in diameter; with 9 foot rubber covered cable 1/2" O.D. w/2 flexible copper wires insulated, plus 2 steel strain wires; to be used down to 400ft. depth while withstanding high pressure explosion waves.  Mfg by Brush Development Company.

How can the transformer work over that frequency range? 

3 Feb 2012 - When the 999 average spectrum plot finishes I'll have a look at the impedance.

Fig HP1	Fig HP2 Transformer
White Red Black Green Blue Case Ground White  - Opn Opn  Opn  Opn Red - -  Opn  Opn  Sht Black - - - Sht Opn  Green - - - -  Opn Blue - - - - - The Red and Blue terminals are physically in line. The Black and Green terminals are physically in line. The White wire is not an electrical connection but rather is where a couple of steel cables attach for supporting the weight of the hydrophone. It's not clear what this is.
HP 4395A Plot 1 Hz to 20 kHz RBW: 1 Hz, True RMS detection, 16 averages:	HP 4395A Plot 1Hz to 20 kHz RBW: 1 Hz, True RMS detection, 999 averages (54.6 hours):
HP 4395A Z transform Impedance Real & Imaginary	HP 4395A Z transform Hydrophone Impedance Smith Chart with Marker List

GEO_ID - TRC-3, PEWS, USQ-42, Turd
GSQ154 - All GSQ-154
GSQ160 - Frequency Disconnect -GSQ-160, USQ-46, TS-2963, PP-6446 - TCw - cylindrical module pinouts.
GSS26 - AN/GSS-26 minimal info
Intrusion Alarm Patents
USQ_Rx - Igloo White, USQ-42, USQ-46 details,
PSR-1 - now on it's own page (July 2007)
Modular Outdoor Intrusion Sensors (REMBASS?)

Sippican's expendable probes - temperature, sound velocity, conductivity, etc.

Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet, 18th Edition (2005) by Norman Polmar
The Ears of Air ASW: A history of U.S. Navy Sonobuoys (2008) - Holler, Horbach & McEachem