Morrow Project Electronics

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GVS-5 Laser Rangefinder


     A magnification 7X45 telescope, with built-in infrared laser rangefinder. The laser is NOT eyesafe, and in fact can be seen though eyelids -- however, since the beam is infrared and very brief, it isn't normally visible if you're lucky enough not to be the target. Permanent and serious eye damage will occur nearly instantly if the beam strikes a person's eye(s) at a range of less than about a kilometer - be careful when aiming the laser at flat reflective surfaces or magnifying optical instruments. It is issued with a padded plastic hard-case, containing a mounting adapter, cleaning and minor repair items, filter assemblies, and a power cable (for running off of vehicle power). The 7 nanosecond laser pulses are 20 millijoules each at 1064 nanometers wavelength; it can 'fire' up to six times per minute (it has to power up its capacitors). The beam starts at 7mm diameter, with a divergence of 4 milliradians (thus 4 meters wide at 1000 meters distance). Ranging is in 10 meter intervals, from 180 meters to 10 kilometers; the user can set a minimum range value, to reject clutter in the way. It uses two Project radio batteries for power; they provide enough power for tens of thousands of rangings. Mass 1.7 kg including neckstrap.


H-161E/U Headset with Microphone


     A headset with two earphones and a boom microphone. It has a noise-canceling microphone, which means your lips need to be close to the microphone. The cable has two plugs -- the short one is for radios, the long one (1.5 meters) is for vehicle intercom systems. There's a switch for push-to-talk, listen only, or listen-and-talk. A "bail-out" connector is installed in the middle of the cord, for quick departure from vehicles.

     Some teams receive different types, but functionally the same; for when you don't want to wear your helmet ...


H-250/U Radio Handset



     For use with most Project radios, intercom systems, etc. It has a cable about 36 cm long when coiled up, or 2 meters long when pulled hard. The microphone has a noise-canceling feature built in. 


LS-166/U Speaker


     Military low-fi 2.5 watt speaker on 60 cm cable; can plug into vehicle intercom systems or directly into most Project radios, frequency range 300 Hz to 7 kHz. Mass 1.8 kg, dimensions 12.5 cm by 12.5 cm by 7.5 cm.


LSS-40 Loudspeaker


     A portable sound system, which can be used by aircraft, ground vehicles, or ground troops (though it shouldn't be operated while being carried!). It's a very sturdy system -- it at least looks like it could be thrown off a truck.

     135 decibel output, frequency response 400 Hz to 6000 Hz. Built-in siren mode.

     It consists of a pair of speakers (4 kg), an amplifier unit and power unit (5.5 kg), and a control unit (1 kg). The two speakers are on a 15 meter cable from the amplifier; the control module has an 8 meter cable to the amplifier (an optional 300 meter cable is available). Input can be from a built-in microphone in the control unit, or any tactical microphone or headset, or from an audio connection from a tactical radio, or from an RCA connector ("phono plug"). It operates at 24 volts DC, and contains a Project vehicle battery; adapters exist for powering it from 12 or 24-28 volt DC sources, or 110/220 volt AC sources; when operating at "full blast" this device draws about 30 watts (thus about 50 hours of full-power sound output). Designed to be carried on a standard ALICE pack. Mass 10.5 kg, volume 30 liters.


PAS-7 Thermal Viewer



     Magnification 4.5X, effective range 400 meters (to spot a man) or 3000 meters (to spot an operating motor vehicle), and is pretty good at penetrating fog, rain or smoke. The minimum range for a focused image is 8 meters. Glass is entirely opaque at the frequencies used by this device (3.2 to 5 microns), so you can't look out through, or into, glazed windows. The display is a roughly 2 centimeter diameter cathode ray tube, showing white (for hot) on green or black (for dark). It uses 4 Project camera batteries in a battery case (on a 2 meter long cord, which can be attached to the viewer, or worn on your belt), and will operate for up to 48 hours. While normally handheld, it can be mounted on a camera tripod. Weight 5 kilograms; the cased item with all cables, lens cleaners, battery boxes, manual, covers, heavy-duty case etc. weighs 20 kg. The case is 50 cm by 48 cm by 33 cm (79 liters).


PPS-5 Radar


     A ground surveillance radar set, first employed by the Army in 1966; it is used on a small tripod, or mounted on vehicles. This device will detect moving objects, including aircraft, out to 7 km for personnel, 16 km for small vehicles, and 23 km for large vehicles or aircraft, but usually less than one-quarter of that in anything but the most level, uncluttered terrain. Range error is 8 meters; CEP is about 45 meters at 20 kilometers. The set will provide information about the approximate size, range, speed, and direction of moving objects; it can track up to 99 moving objects simultaneously. There is also an integral alarm that can be set to sound automatically for a specific set of size, range, or speed. Rain, sand or dust storms will make interpreting the signal more difficult.

     Operation of the set requires some training -- the visual and (especially) the aural displays take a bit of interpreting to use. The set can display all objects (which results in lots of ground clutter) or only moving targets. Most Morrow Project personnel have spent a day or less being trained on the use of this item; reading the manual might be wise. Signals or Electronics skill of 40% or more allows the user to operate this set at full potential with a bit of practice; or any background involving radar usage ...

     Weight of receiver/transmitter with tripod, antenna drive, control-indicator box, printed manual, and power supply, 35.5 kg; it's normally stored in a footlocker-sized case (mass 8 kg), but can be backpacked by three men. It's air-droppable and thus reasonably sturdy. 

     The set requires 24 volts DC power; for the Project, the battery box contains four Project radio batteries. They provide enough power to operate the set for 24 hours -- it's normally connected to a vehicle power supply. This set cannot be connected to the Autonav.


PRC-68 Personal Radio


PRC-68 radio


     A hand-held FM receiver-transmitter, manufactured by Magnavox from about 1976 onwards. It has a built-in speaker-microphone, or can use various of the standard tactical handsets and headsets of the US military. Two antennae are supplied; with the short "rubber ducky" antenna the range is only 300 meters. The 70 cm long "tape" antenna gives a range of 1600 meters; though range for either antenna is dependent on the terrain. The radio is considered waterproof to a depth of about 1 meter. A Project radio battery provides about 170 hours of power (presuming you're mostly listening). Transmission power is about 1 watt.

     There are 1000 available channels, in the 30 to 80 megahertz band (which includes TV channels 2, 3, 4, and 5). Ten channels are preset by several knobs on the radio, and then the channel selector allows quick changes between channels. Channel setting is actually rather technical; you need a field strength meter to tune the antenna coupling module. Weight with battery and rubber-ducky antenna installed 1.3 kg; tape antenna weighs 0.2 kg, and spare radio battery weighs 0.36 kg.  

     Note that the picture for the PRC-68 in Project manual TM 1-1 is incorrect -- it shows a URC-68. From 1984, the PRC-68A was issued, with small improvements. From 1986 onwards, some teams in the Project were issued the similar PRC-126 radio (1.42 kg with battery and antenna; covers 30 to 88 megahertz band, slightly longer ranges). The following items may be issued with this radio:


PRC-70 Tactical Radio



ARN-89 Direction Finder


the control panel


     A radio direction finding system for AM or CW signals between 100 to 3000 kilohertz. The components are a 30 cm wide flush-mount antenna on the top of the vehicle or station; a receiver unit, a set of cables, and a control unit at the operator's position. It can be used for automatic homing (tracks the direction of a moving signal) or manual mode (you turn the loop and listen to the audible signal). It operates on 28 volt DC power. Weight including control unit, receiver, cables and roof-mounted antenna, ~6 kg.

     Usually also installed is a compass indicator -- a small dashboard-type item, to indicate heading for the vehicle driver or pilot. It shows vehicle bearing (obtained from the Autonav) and the bearing obtained from the radio compass system. The ID-1351/A is typical:



PSC-3 Satcom Radio


PSC-3 Components


faceplate of the receiver/transmitter unit


     It's a man-portable backpack unit. 14.51 kg including all accessories. The high-gain satellite antenna can be (and often is) mounted externally on a vehicle; the low-gain whip antenna attaches directly to the transceiver box. It operates on UHF frequencies from 225 to 400 MHz, at 27.8 watts (only 2 watts for LOS signals with the whip antenna). It can transmit and receive digital data, facsimile, teletype, etc. with the proper interface cables; but is normally used either as a voice system, or for encrypted text messages. The radio receiver/transmitter unit itself weighs 6.8 kg, with a volume of 6.5 liters, and comes in a canvas bag. It can be immersed in 1 meter of water for 2 hours. The accessories provided by the Morrow Project are:


PVS-4 Starlight Scope



     A second generation night vision telescopic sight, sometimes called the M9823. It provides 3.5X magnification, and the user can identify a man-sized target out to 600 meters at night. It will not provide an image in absolute darkness (such as a cave). It uses 2 Project camera batteries, which provide power for 48 hours. It's normally supplied with a sturdy, foam-padded fibre storage case, a padded nylon carrying bag (with three D-rings for attaching to your web gear), a pad of cleaning tissues, an artist's brush for cleaning the optics, and a couple of small tools for mounting and adjustment. Mounting hardware exists for attaching it to M16 rifles, LAW rockets, M79 grenade launchers (rotates to be useful for indirect fire), M14 or M21 rifles, M60 machine-guns, M2HB machine-guns, M67 and M40A1 recoilless rifles, MK19 grenade launchers, and several other 1960s-1970s Army weapon systems -- if not otherwise stated, Project PVS-4 sights come with M16 and M14 mounting hardware, and reticles meant for 7.62mm NATO ammunition, or 5.56mm ammo and 40mm grenades. Weight 1.75 kg.


PVS-5C Electronic Binocular



     Night-vision goggles, operating in the near-infrared spectrum. Designed to be worn on the head with a set of straps; if worn for more than four hours, eye fatigue sets in. Considered to be sturdy, with exceptional 4x optics; they're of reduced usefulness in bright light. A built-in infrared illuminator allows them to be used in total darkness. The field of view is only 40 degrees at 1x magnification, and the user can't really focus on weapon sights or optics, vehicle instruments, hand-held text, etc.. They use two Project camera batteries, which give a battery life of 100 hours. In a depot or large vehicle they are stored in a substantial, padded metal transit box ("Case, Storage, Goggles, Night Vision", weight 5.7 kg, volume 0.04 cubic meters), which contains a smaller, padded plastic field storage box. In some cases they are also issued with an olive drab belt pouch. Weight 0.85 kilograms (not including the transit box or field storage box).

SPS-59 Radar


AN/SPS-59 radar set


     A surface-search radar, used aboard some Morrow Project watercraft. Peak power is about 10 kilowatts, at 9375 MHz. The antenna is a 1.22 meter long bar, connected by waveguides to the electronics belowdecks.

     The control unit display is an 25 centimeter diameter PPI scope (plan position indicator); it provides a map-like representation of the area around the radar. Coastline contours are generally depicted as solid-filled green echo areas; other surface targets are displayed as smaller single echoes. On land, the radar is most useful over flat terrain -- mountainous or even just rugged terrain will be displayed as a solid green image at nearly every distance.

     Besides the antenna and the PPI unit, there is a receiver/transmitter, power supply, and a rubber sunshield.

     Maximum detection range of a wooden boat is about 8 kilometers, with a more typical (90% likely) range of 3 kilometers. A steel trawler can be detected at 18 kilometers range very reliably (90% likely). Keep in mind that this radar unit is line-of-sight only. Startup time is six minutes "electrically", probably 10 minutes to set all the controls, etc.

     The control unit can be connected to various other navigational devices and sensors -- some electronic compasses and specifically the Autonav are able to receive data from the radar.

     Note that operation of multiple radar units of about the same frequency will produce mutual interference patterns on the PPI.

     System weight 120 kg.


     The following items are not AN-series equipment.


Autonav Model A1B



     A vehicle-mounted inertial navigation system. Normally powered from the vehicle, but a normally-installed Project radio battery will provide power for 12 hours in an emergency. The Autonav displays maps at various scales on a 24 cm diameter circular screen; it contains map data for most of North America, and the location of the caches for the team. Project training states that some map data is stored on microfilm within the Autonav; it can also use map images from the Laserdisc Drive. Display scales are:  1:10,000 (that is, 100 meters per grid side) ; 1:25,000 (which is 250 meters per grid side); 1:50,000; 1:250,000; 1:1,000,000; 1:2,500,000; and 1:5,000,000 (which is 50 kilometers per grid side, or 1200 kilometers across the screen width). Note that while the Autonav has seven display scales, the internal data is only at the 1:250,000 scale; more detailed maps come from the Laserdisc Drive, although most geographic areas don't have data any better than the 1:25,000 scale. It can also be used to provide gun-laying information and indirect fire information. Data connections from radar sets, gyro compasses, radio-direction finders, sonar or magnetometer sensors can be fed into the Autonav and displayed on the screen. A Morrow Project ID card is required to use the Autonav; there is a self-destruct system built-in, with a small thermite charge (shouldn't mess up much outside of the cabinet). Dimensions 60 cm wide, 34 cm high, 30 cm front to back; mass 18 kg including battery.

     The similar A1C has different armament options (including settings for the 90mm cannon); the A1D version has no armament options, weighs 10 kg, has a tripod-mounting adapter on the bottom, and is only about 44 cm wide.


Furuno FR-802D Radar


control/display unit


     A surface-search radar available from 1985 and fitted to some Morrow Project watercraft. The antenna is an 80 cm bar, rotating in a flat dome. The antenna dome must be mounted within 30 meters of the display unit; but at least 3.1 meters away from a magnetic compass, and at least 2 meters away from a direction-finding antenna.

     Power supply is either 12 volts, 24 volts, or 32 volts DC; it uses 95 watts of power. A rectifier option allows the radar to operate on 110 or 220/240 volt AC power.

     The control unit has a display 30.5 cm wide. Range gates are from 100 meters to 58 kilometers -- however, the display can be adjusted (via dip switches internally) to present nautical miles rather than metric units.

     A "guard alarm" is fitted -- if a target appears within the distance and angle selected, an alarm will sound. The radar will plot movement (ARPA) of up to 20 targets, for up to 100 minutes.

     This system can interface with the Mk 23 gyro compass, AutoNav, speed log, and other peripherals. A repeater display unit, with a 26 cm tall LCD screen, is available; it displays exactly the same information as the "main" display, but has only controls related to course plotting and the guard alarm.

     The manual can be seen here.

     Antenna weight 19 kg, receiver/transmitter weight 16.5 kg, tabletop- or bulkhead-mounted control/display unit weight 20 kg, LCD repeater display, ~7 kg.


Gavilan SC Computer


       Another laptop, seen in Science teams mostly. and at least somewhat PC-compatible. The Ni-Cad batteries will power it for about nine hours. Includes a 3.5" diskette drive, space for four 32 kilobyte "plug-in" RAM capsules (only 32 kilobytes are "built-in"), and a built-in touchpad (like many 21st Century laptops).


The Apple Macintosh of 1984 was the first commercial computer with a mouse.


     The screen is only 400 by 64 pixels, but can display simple graphics. Gavilan Computer Corporation declared bankruptcy sometime around 1983 or 1984, but deliveries of the computers were slowed by trouble obtaining the disk drives. Mass 4 kg.

     A printer using 8.5" wide thermal paper is available; the paper comes in rolls of 32.8 yards (~107 sheets).

     A thick, white binder filled with user guides, reference pages, etc. is usually present when the computer is issued, along with software packages in RAM capsules (about 0.2 kg each).


GRiD 1103 Compass Computer


     An early laptop computer, most often seen in use by MARS teams. The proprietary operating system isn't easily compatible with other Project gear. It's very sturdy, since the bubble memory doesn't have any moving parts. First issued in 1982 as the 1101 Compass, which operated only on 110 volts AC "wall power"; the more common, later 1103 version includes a battery. It has one of the first amber flat-plasma screens. Various later versions were acquired by the Project, probably seen only on MARS-One vehicles. 4.6 kilograms weight.

     A separate floppy drive is available, for 5-14/" discs.

     The Project can provide an external battery box, which contains a Morrow "radio battery".


Laserdisc Drive



     An accessory for the Project PC (or some other small computers). It reads information from a 12" laserdisc, which contains 320 megabytes of data, although not actually stored in digital form. They store frame-by-frame video representations -- basically like microfilm -- of books. The drive weighs 21 kg, and cannot be used on most moving vehicles (or at least not in a moving V-150). The disc takes about 15 seconds to spin up to speed, and can function as a "regular" media player (if you find any movies or music on laserdiscs). The phrase "PROPERTY OF THE U.S. GOVERNMENT" is apparently buried deep in the hardware, and appears during startup. A remote control is included, mostly for when you're using it as a media player. There are several standard laserdiscs and sets of laserdiscs available; each weighs 0.4 kg in a plastic sleeve:

Lowrance X-3 Sonar


     Instructions here. It operates on 12 volts DC. Range 150 meters (but some skill is required for ranges under 12 meters) for finding fish; the transducer projects a 20 degree cone down from the vessel's keel, so not usually very far away from the boat "on the map". There are alarms which can sound or display if the bottom, or a target not on the bottom, come within a certain range (out to about 300 meters). It provides information on a liquid crystal display. 21 cm wide by 12.6 cm high by 6.7 cm deep; mass 0.8 kg.


Alarm Monitor Set


     A rack-mounted radio receiver and display. It has a simple grid of lamps which light up to indicate which sensor has triggered; and a simple speaker or headphone jack to give an audio alarm. It's powered by an MP "radio battery" for up to a week, or can be powered by 12 or 24 volt DC vehicle systems. It has a short whip antenna which can be mounted on the receiver itself, or externally on a vehicle or structure. Mass 2.3 kg.


Portable Alarm Monitor Set


     A radio receiver to be hand-carried, or worn on a Project member's LBE. It is a small flat box, with a short rubber-coated antenna, and an earphone on a cord (the earphone has a 1/4" audio plug). The box has two switches to set the frequencies, one with settings OFF-LAMP-ALARM-BOTH-SET, a volume control knob, a small speaker, and two small lamps. A single Morrow Project "camera battery" will operate this item for several weeks. Dimensions 11 cm by 8 cm by 3 cm, mass 0.25 kg.

     Unlike the larger Alarm Monitor Set, this item will only detect two frequencies. If the earphone is plugged in, the speaker is disabled. It happens to fit in the external "spare battery pocket" on the carry pouch for the PRC-68 radio, or in a coverall pocket.


Magnetic Intrusion Detector


     This battery-powered remote sensor reacts electrically to ferromagnetic material in a vehicle, weapon, or item of apparel which may be driven, transported, carried, or worn by an intruder. The sensor performs some electronic amplification and analysis; if the signals have the required characteristics, it sends an encoded radio signal, on a preset frequency between 162 and 174 MHz, with a power of about 2 watts. It should be placed within 500 meters of the Alarm Monitor Set, or 200 meters from the Portable Alarm Monitor Set. It can detect a moving rifle at 4 meters, and a vehicle at 20 to 30 meters; it can (and should) be buried under a few centimeters of soil.

     A single MP-AA battery will power the detector for a month. Physically, it's a flat olive-drab box, with a 40 cm rubber-coated antenna, designed to resemble a twig or leafless bush; mass 0.8 kg. Under a rubber cover are the battery and three rotary controls; one sets the mode (OFF, TEST, ARM), the other two set 2-digit alpha-numerical values. There is a built-in tilt sensor; if the detector is moved a lot, a self-destruct pulse will destroy the electronics. The self-destruct function can be disabled by entering the correct code using the rotary switches.


Seismic Intrusion Detector


     A battery-powered remote vibration sensor. The unit is a two olive-green cylinders, somewhat resembling a pair of binoculars, issued with a nylon carrying strap. It includes a built-in anti-tampering switch -- if the detector is picked up while switched on, the anti-tampering switch will disable it permanently. There's a simple 40 cm rubber-coated antenna, designed to resemble a twig or leafless bush; the detector should be placed within 500 meters of the Alarm Monitor Set. The geophone (the actual sensor component) is a metal and plastic spike on a short cable -- it should be buried at least 15 cm deep. Two Morrow Project "radio batteries" are installed; they will run the sensor for six months. The detector weighs about 3.6 kg. The sensor transmits on the 162 to 174 MHz frequency, with about 2 watts of power. There's an internal switch with three functions:  OFF, TEST, and ARM. Two internal rotary switches allow the users to set the transmitting frequency (on one of 39 channels), encoding of the radio signal (including  a six-bit identification of the specific sensor), and disabling the self-destruct pulse.
     The sensor will detect walking people out to 50 meters, wheeled vehicles in motion out to 250 meters, and tracked vehicles in motion out to 350 meters. It will transmit a signal at most once every 10 seconds. The gain can be adjusted to avoid false alarms due to wind, rain, small animals, etc. (this is done by adjusting a jumper cable inside the unit).


Mk 23 Gyrocompass


     In full, it's the Mk 23 Mod C-3; earlier versions had some vacuum tubes, but this model is entirely solid-state. Major components are control cabinet, power converter, and master unit (the actual gyro; mass 45 kg), plus several repeaters if needed. Minor items are repeaters, a speed unit (transfers ship's speed information to the gyrocompass), a failure alarm light, an alarm control, and a failure warning bell. The Autonav is actually more capable, but this compass is left installed as a backup on some Project boats and ships. The Mk 23 is only accurate up to 40 knots; it must be operated in a different mode at latitudes above 75° North, or below 75° South, and isn't as accurate at arctic latitudes. It should be allowed 2 hours to settle before being required for service. A built-in Morrow Project radio battery will keep the gyrocompass operating for several hours.

     The repeater cable for this item can be connected to the Autonav, although there's not much reason to do so.


Morrow Project PC



     A ruggedized version of a 1983 personal computer (probably the TRS-80 Model 4P). Includes 22 cm black-and-white monitor, keyboard, 128 kilobytes of RAM, 5.25" floppy disc reader, a Grafyx Solution high-res graphics add-on (which allows the display of both text and graphics), 300 baud modem board, and 1 m long power cord; an external 3.5" diskette drive is also included. The Project doesn't use 5.25" floppy disks, but the computers have that drive built in. The computer needs 110 volt, 60 Hz AC power to operate. A plastic "shoe box" with eighty 3.5" diskettes is included with the computer; about half are blank, but the other half contain software (including, at least, a spreadsheet program, text-editing program, disc library manager, MDRAW (a freehand drawing program), a GIF viewer, a very early CAD program by Microdex, and a BASIC compiler) and Project-specific text (first aid guides, and manuals for equipment, mostly). The computer and some diskettes are (or can be) password-secured, but none of the data on the diskettes or hard drive is particularly revealing -- nothing about how to build a fusion reactor, for example. Most of the manuals are US military books, in fact; see the back of TM 1-1 for some examples. An olive drab nylon carry bag for the computer, external drive and diskette box is usually issued with the computer. The computer weighs 12.5 kg, the external disk drive is 1 kg, and the 'shoe box' of diskettes weighs 1.75 kg; as a kit in the carry bag, they weigh 16 kg.

     It's quite likely the Morrow Project has stocks of accessory and peripheral devices for this system, such as printers and color plotters. 


USM-338 Oscilloscope



     A militarized version of the Hewlett-Packard 1707B solid-state 75 MHz dual-trace oscilliscope; 6×10 cm display. Built into a sturdy plastic olive-drab waterproof case (front and rear covers can be removed), includes  contrast filter, power cord, service kit (includes three extender boards and one board puller), probes and printed manual. Runs on 115 or 230 volt AC power, or 12 to 38 volt DC power (25 watts maximum), or its internal battery (a Morrow Project radio battery, good for at least 6 hours of operation; it has to be recharged outside of the oscilloscope). 26 cm by 33 cm by 51 cm; mass 19 kg. 

     Mostly used for radio repair and adjustment.


Raytheon DE-736 Fathometer


     Entirely transistorized. Displays depth under keel in fathoms or feet, down to 60 feet or 60 fathoms (same dial marked 0-60). Only two controls:  off/on-gain, and fathoms-or-feet switch. Operates on either 115 volt AC power, or 24 volt DC power. Display unit is 21 cm high, 25 cm wide, 15 cm deep (thus about 8 liters), weighs 2.3 kilograms.


Raytheon Pathfinder 1900ND Radar

control and display unit


     A surface-search radar, used for navigation by some Morrow Project vehicles (small watercraft especially). Peak power is about 5 kilowatts; it operates on either 115 volt AC power, or 24 volt DC power, and consumption is about 250 watts (including the antenna drive of 100 watts). The antenna housing is a roughly 1-meter diameter Resistweave-fiberglas sealed tub, mounted on a short pedestal.

     The display is an 18 centimeter diameter PPI scope (plan position indicator); it provides a map-like representation of the area around the radar. Coastline contours are generally depicted as solid-filled green echo areas; other surface targets are displayed as smaller single echoes. On land, the radar is most useful over flat terrain -- mountainous or even just rugged terrain will be displayed as a solid green image at nearly every distance.

     A rubber sunshield is provided for the operator to use as needed. Five control knobs are present on the face of the control unit:  power (off, standby, operating); gain and clutter control; range; tune; and intensity. The radar takes 90 seconds to warm up from "off" -- the standby setting can be used to shorten this time. There's a 360 degree scale marked around the edge of the scope.

     The radar picture can be viewed in four sizes or scales; greater detail of radar echoes is shown when using the shorter range scales. The range settings are:  30 kilometers, 10 kilometers, 3 kilometers, and 800 meters. Resolution is about 4% of the range setting -- thus at 800 meters range setting, objects down to 32 meters in size can be identified. Bearing accuracy is about 1 degree.

     Maximum detection range of a wooden boat is about 5 kilometers, with a more typical (90% likely) range of 1.6 kilometers. A steel trawler can be detected at 12 kilometers range very reliably (90% likely). Keep in mind that this radar unit is line-of-sight only.

     The control unit can be connected to various other navigational devices and sensors -- some electronic compasses and specifically the Autonav are usually able to receive data from the radar.

     Note that operation of multiple radar units of about the same frequency will produce mutual interference patterns on the PPI.

     Weight of rotating antenna and dome:  7 kg. The control/display unit has a volume of about 6 liters, and weighs about 10 kilograms. Other cables, antenna pedestal, and minor accessories vary according to vehicle configuration, but the system weighs at least 20 kg all told.