011865
A REPORT ON
FIELD TESTS AND COMPARISONS OF
SHIPBOARD DRIFT-BUOY FINDING
SYSTEMS
ARCTIC
SCIENCES
LTD
A REPORT ON
FIELD TESTS AND COMPARISONS OF
SHIPBOARD DRIFT-BUOY FINDING
SYSTEMS
by:
Gary R. Wilton
for:
Institute of Ocean Sciences
Patricia Bay, B.C.
Arctic Sciences Ltd.
P.O. Box 2639
1986 Mills Road
Sidney, B.C.
V8L 4C1
(604) 656-0177
March 31, 1981
i
Acknowledgments
This contract was awarded as a result of
an unsolicited proposal (UP-A-235) and was
funded by the Department of Supply and
Services, Fisheries and Oceans Canada.
Much of the equipment used in this
proj~ct was loaned to us by various groups at
the Institute of Ocean Sciences, Novatech
Designs Ltd. and Bastion City Charters.
We would like to thank Mr. D. Knight for
his help in collecting the data, Mr. D. Fissel
for editing the report and Capt. B. Littlejohn
and Mr. D. Littlejohn for their ideas and
assistance while aboard the M.V. Bastion City.
Finally, we would-like to ex~ress our
appreciation to Dr. J. Garrett, Institute of
Ocean Sciences, for his unfailing support and
assistance through all phases of this study.
~RCTIC
SCIENCES LTD ,-,-
1
1.
Introduction
In the past decade, oceanographic research has derived
considerable benefit from the data-relay and precision
positioning capabilities achieved with modern earth satellite
systems.
Thus, for example, Lagrangian measurements of surface
currents and other watei and atmospheric parameters are now
routinely obtained from beacon-equipped drifting buoys.
Moreover, with the increasing sophistication of our
oceanographic understanding, requirements have gradually.risen
both in~the needed numbers of such buoys and in the duration and
frequencies of coverage.
The ubiquitous inflation in the cost of
electronic and other components, as well as in the operational
data relay and processing services (System ARGOS), has created a
need for reliable methods of locating freely drifting buoys by an
oceanographic vessel in order to retrieve them for servicing and
re-use. The satellite-location system itself has limited utility
in this respect due to the time delay, commonly 2.5 to 8 hours,
between each position determination and the relay of results to
the user.
The present study was directed toward the field-testing of
several commercially available beacons which could be attached to
satellite-tracked buoys to serve as an auxiliary, "close in" buoy
locater.
The locating range required of these beacons may be
calculated assuming the maximum 8-hour delay in obtaining buoy
positions from System ARGOS and a 50 cm/s buoy drift speed.
Under such conditions, the buoy could be expected anywhere within
an approximate 9 n.m. circle about the 8-hour-old System ARGOS
position which itself is only localized with 95% confidence to a
circle of roughly .6 n.m. radius.
With allowance for the current
speed de~endence, a nominal 10 n.m. range would seem to be a
reasonable requirement for a close-in location system.
To field test commercially available beacons, several
cruises were made to local waters.
In each cruise, the locator's
range of reception and the directional reliability of the beacons
were measured.
Each cruise provided the opportunity to test
under different conditions as well as allowing for testing of
modifications carried out on existing devices.
2
2.
Testing Procedures
Five field tests of various beacons were carried out, three
in Georgia Strait, one in Juan de Fuca Strait and one land test
(see Figures 1, 2).
Each successive cruise established the
different variables affecting the range and directional
reliability of the various beacons.
1,
\
1
In the first two cruises, the beacons were mounted on a
surface platform that was mo.ored to the bottom, with the bottom
of each ·.beacon in the water (see Fig. 3).
During the third
cruise the beacons were tied to and alongside a satellite drifter
buoy that was anchored, and during the final cruise beacons were
inside the buoy as well as tethere~ alongside.
The two vessels used in the cruises were the M.V.
City and the C.S.S. Vector.
The Bastion City is a 66'
vessel with its upper deck 18' above the water (see Fig.
C.S.S. Vector is an Institute of Ocean Sciences vessel
length with its upper deck 30' above water.
3.
Bastion
charter
4). The
150' in
Tests and Results for Each Cruise
!n this section, we present a brief narrative of each
cruise, outlining the procedures and results of each test and
providng comments concerning special difficulties or unusual
results. A summary of all cruises is provided in Table 1.
I:
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VICTORIA
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METCHOSIN
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JUAN DE FUCA STRAIT
WILLIAM
HEAD
Figure 1:
Location of transmitter and check points during test (/2.
*
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TRANSMITTER
LOCATION
CHECK POINT LOCATIONS
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Test 3
JUAN DE FUCA STRAIT
If.~.~.~.: .... l'''-~·''_, .. " __ ",:, ' ..... ...:;to::.!!".; 1
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Figure 2: Location of cruise tests.
GEORGIA
5
Figure 3:
Beacons
rnou~[~d 0~
1 moor~d
pl~tf0rm.
6
Figure 4:
Charter Vessel Bastion City.
DATE
SHIP - AREA -
AND PERSONNEL
TEST 01
Bastion City
Jan.9/81
Strait of Georgia
G.
D.
D.
J.
Wilton, ASL
Knight, ASL
Bowker, ASL
Wallace, lOS
HEIGHT
1
5
1
1-1
1-6
21
36
21
21
21
TEST #2
Land Test
Feb.4/81
Victoria Waterfront
D.
D.
J.
R.
TEST03
Knight, ASL
Tuele, ASL
Wallace, lOS
Corman, Novatech
G. Wilton, ASL
D. Knigh t ASL
T. Lusco~e, ASL
TEST 04
G.
R.
J.
W.
TEST 05
Wilton, ASL
Corman, Novatech
Wallace lOS
Large, Boulder Co.
1
5
G. Wilton, ASL
D. Knight, ASL
J. Wa Uaee, IDS
---l
Transmi t ters:
VHF - same as Test #1 and 2.
HF - saroo as Test III and 2.
CB - same as Test ill and 2.
40
21
40
Receivers:
VHF - sarre as Test III and 2.
HF - hand held directional receiver, no brand name.
CB - OAR Model FR206.
.5
2
2
2
Transmitters:
3 - VHF - Novatech RF200
Channell - 200 msec/sec, .150 watt, 1/4
Channel 3 - 200 msec/sec, .400 watt, 1/4
ChannelS - 200 msec/sec, .150 watt, 1/4
1 UHF - 401.650 MHZ - Handar Electronics
30,50
35
Receivers:
VHF - Novatech DR400
UHF - OAR Automatic Direction Finder ADF 335
Bastion City
Mar.18/8l Strait of Georgia
Transmit ters:
Novatech.VHF Model RF200
Channel 1 - 150.815 MHZ 200 msec/sec duty cyc1e,1/4 wavelength antenna,.150watt
Channel 3 - 150.845 MHZ 100 msec/sec duty cyc1e,1/4 wavelength antenna,.150watt
Channel 68 - 156.425 MHZ 100 msec/sec duty cyc1e,1/4 wavelength antenna,.150watt
1 - Electro Marine Corp. HF Model 500 2.398 MHZ ;., I.O.S. Packaging
2 - OAR CB transmitter: Channel A - 26.995 MHZ-pu1se Signal
Channel E - 22.195 continuous signai ,
2 - Strobe lights: OAR - intermittent day and night
Guest - photo cell activated
Receivers:
VHF - Novatech Direction Finding Rec.DR400, Regency Polaris Scanning Rec.NCnOO
HF - Collins receiver
- Hand held directional, - no brand name
CB - OAR, Finder Receiver Model FR206
Strobes - visual sightings
Transmitters:
3 - VHF as in Test #1
1 - HF as in Test III
2 - CB as in Test III
Receivers:
22,34 VHF - Novatech DR400
10
- Apelco Walkie Talkie (Channel 68)
10,24,36 HF - as in Test Ill.
10,22,34 CB - 2 OAR Model FR206
Vector
Feb.26/8l Strait of Georgia
TIS::;Tl!JJ
4
9
4
Bastion City
Feb.21/81 Juan de Fuca Strait
DEVlc..:~::;
ANTENNA Fl'.
2
.5
40
25
wavelength antenna
wavelength antenna
wavelength antenna
in a Hermes Drifter Buoy
Transmitters:
4 - VHF Novatedl RF200
Channel 1
- 200 msec/ sec
.
Channel 6~, 70 - 200 msee/see, Channel 3, 100 msec/see
Receivers:
~iF - Novatech DR400
- Regency Polaris Scanning Receiver, NC7100
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8
Test!!
=M.V.
Bastion City
=January
~
1981
The transmitters were mounted on a moored platform in 100
fathoms of water due east of Valdes Island in the Strait of
Georgia. The wave conditions were very mild with only ripples
appearing in the water surface under very light wind conditions.
The cruise plan was to lay beside the mooring and verify
operation of the beacons and receivers, then move away from the
mooring in 1 n.m. stages, stopping and noting signal strength and
directional accuracy until there was no reception.
~he
VHF signals worked well out to 5 n.m. where Channel 3
became seriously contaminated by noise interference from taxi
transmissions, resulting in difficulties in determining the
direction.
The Polaris scanning receiver (see Appendix for
specifications) was starting to read intermittently at the same
distance. At 6 n.m. the VHF signals were weak and a consistant
direction was hard to establish, and by 6.5 n.m. range all
signals disappeared.
The HF signal was very weak at 4 n.m. and disappeared
completely at 5 n.m.
The Collins receiver did not work at all.
Channel A of the CB worked and had a faint bleep out to 6.5
n.m., but it was never possible to determine a direction from it.
Channel E was far too noisy to even detect a signal. We lost
sight of the O.A.R. strobe at 1/4 n.m., and the Guest model at 1
n.m.
As we proceeded back to the mooring from 5 n.m. we "homed
in" using the Novatech DR400 (see Appendix for specifications).
We proceeded 5 n.m. past the mooring to see if land masses or
direction made any difference, but, there were no discernable
differences in the results.
Our tentative conclusions from this
cruise were:
1.
Metal structures behind a receiving antennna seemed to
result in directional problems for VHF receiver and even
more so for the CB receiver.
2.
The line of sight of radio transmissions given the heights
of the antennae is between 5 and 6 n.m.i this corresponds
well with the measured range from these tests.
3.
We were a bit suspicious of the limited range of the CB
system; another unit would be obtained for the next cruise.
To reduce problems resul ting from the metal structures and
line of sight limitations, it was decided to build a 20'
9
mast for mounting the CB and VHF antennae prior to the next
field tests.
4.
The HF transmitter antenna was found to be broken;
were made to it and the other items not functioning
#1.
To ensure proper operation of these devices and
the equipment without the line of sight restrictions
#1, the second test was carried out over water
pofnts of land, near Victoria.
repairs
in test
to test
of test
between
10
Test i2 :: Land
~
:: February
~
1981
Transmitters were placed at Harling Point 3' to 4' above sea
level. The first reception point was at Clover Point, located
about 1 n.m. from the transmitters at IS' to 20' above sea level.
Albert Head lighthouse was the next check point 6.3 n.m. from
transmitters at 30' above sea level.
Weir Beach at 9.5 n.m. from
transmitters was the final location at 6' above sea level (see
Fig. I).
The HF system did not function at all.
The VHF started
experi~ncing a lot of radio interference at 6.3 n.m.
The signals
were there but taxi transmissions were overriding these signals
reducing directional reliability. The Channel 68 transmitter was
d_etected clearly except when an intermittent signal of unknown
origin was present.
The VHF signals at 9.5 n.m. were very
erra tic and not reI iable.
The CB tes t showed the or ig inal
receiver was still not working,properly.
Channel A signal
direction came in strong but Channel E could not be detected.
A
high level of radio interference almost blanked out direction
detecting at this test site and a directional bearing could not
be obtained at 9.5 n.m.
In conclusion, the land test seemed to have the same results
as test iI, on the VHF frequencies.
Preparations, were begun for field test #3, aboard the M.V.
Bastion City. The major objective was to test equipment under
more typical wave conditions and to test the use of receiver
antennae at extended heights, as compared to test #1.
11
Test
!l
=M.V.
Bastion City
=February 21,
1981"
The transmitters were mounted on the same moored platform,
in 95 fathoms of water, as in test #1, at a site in Juan de Fuca
Strait 4 miles south ofSooke Harbour.
The sea conditions were choppy with a 5 second 4'-6' swell.
The cruise plan was to proceed away from the mooring until all
radio contact was lost with the transmitters.
The VHF system, having the antenna mounted on a 20' tower
raising it to a total height of 38' above sea level, became
erratic at a range of 5.5 n.m. hitting and missing on both
receivers.
No definite direction could be distinguished,
although the signals were coming in strongly, particularly on
Channel 1.
HF signal strength at 5.5 n.m. was very weak and at its
upper limit for a directional bearing.
The CB signal strength was strong" although outside radio
interference made it impossible to get a consistant directional
reading.
The results of this test inqicated that the received signal
from the VHF was modulated by the local waves, strengthening and
weakening with the swell.
This effect, when combined with local
radio {nterference from other sources, makes it difficult to
determine the correct direction.
The same problems were experienced with the HF and CB
signals as on the previous tests, with resulting short
directional ranges limited by the weak signal re~eption in the
case of the HF system and due to excessive outside noise in the
CB channels. On the basis of these results it was decided to
discontinue further testing of the CB and HF systems.
For the next test it was decided to increase the VHF output
duty cycle to 200 msec/sec in all the transmitters, as the signal
from the duty cycle in Channell was much stronger in test #3,
and also to increase the power output in one transmitter to 0.4
watts from the previous level of .15 watts, to see if any
difference in directional range.
12
Test!!
=C.S.S.
Vector
=February
26, 1981
The purpose of this test was to evaluate the recently
developed Ocean Applied Research Corporation's automatic
direction finder (ADF335) which just had returned -from successful
recovery of six satellite buoys in the Pacific Ocean near Station
Papa.
This system detects the UHF signal transmitted by the
satellite-tracked buoys.
In addition, a comparison with the VHF
system using an increased duty cycle would be made.
A
transmitting Hermes satellite drifter buoy was moored in 90
fathoms of water in the Strait of Georgia with two beacons lashed
to its cone, out of the water, and one tethered alongside
. floating in the water. The wind and sea conditions during this
test were calm.
The UHF ADF335 gave consistent and good directions out to 6
n.m., and intermittent directions out as far as 8 n.m. with
sporadic directional fixes at 10 n.m.
The VHF signals as measured by a hand held antenna and
receiver, approximately 30' above sea level, were detected at a
10 n.m. range with good directional fixes.
All channels were
noisy with taxi transmissions but Channel 3 came in markedly
better than the others. At 12 n.m. range, Channels I and 3 had
signal but were not sufficient for directional fixes.
Channel 3
was strongest and Channel 5 was too noisy to even detect a
signal.
At this point, the VHF receiving antenna was mounted on
the 20' mast which raised the antenna to 50' off the water.
Strong signal strength and good directional fixes were obtained
at 12 n.m. range.
On returning to the mooring site, the VHF receiver (using a
hand-held antenna as before) picked up the beacon signal and
direction consistently from 10 n.m.; from inside the bridge on
the Vector, the VHF antenna and receiver operated at a distance
of 5.3 n.m. and less.
The UHF rece i ver picked up the signal
consistantly from 8 n.m. and gave reliable directions from 5
n.m.
However, the UHF device occasionally gave incorrect
directions for all ranges.
The results of the VHF test were much better than those of
previous tests and seemed to be related to the increased duty
cycle. It was decided to make another test on the Bastion City
with one original transmitter and two using the increased duty
cycle to verify this hypothesis. A way to incorporate the beacon
into an existing satellite drifter buoy would also be explored.
13
Test #5- M.V.Bastion City
=March 18,
1981
The purpose of this final test was to verify the results of
the previous test and to test the operation of a beacon from
inside a drifting buoy. During this test the wind was blowing 15
knots and the sea was choppy.
An inactive Hermes Drifter Buoy was moored in 90 fathoms of
water in Georgia Strait.
Originally two beacons were placed
inside the buoy and three tethered alongside floating in the
water. After a few minor problems with batteries etc., Channel 1
was mounted inside the buoy while Channels 6& and 70-were
tethered in water beside the buoy.
The Channel 1 signal was strong at 12 n.m. and reliable
direction fixes were obtained. The Channel 68 signal was lost at
4 n.m. on the DR400 receiver and 2.5 miles on the Polaris
receiver and the Channel 70 signal was lost on the Polaris
receiver at 5 to 6 n.m. Channels 1 and 3 were then tethered in
the water and successfully tracked out to 10.5 n.m.
While
Channel 1 signal was medium strength, at this range, Channel 3's
signal was weak with a lot of taxi radio transmission
interference.
The battery output in the Channel 68 transmitter was later
determined to be too low, accounting for the poor reception range
of this transmitter. The ranges measured in test #5 confirmed
those of the previous test and demonstrated the success ~f
tracking a VHF beacon mounted inside a satellite buoy.
14
Summary and Conclusions
The results of this study show that VHF transmission offers
a feasible means of tracking free floating objects in the ocean
and is superior to CB and HF systems. CB signals suffer from a
high level of noise and interference from surrounding metallic
objects making direction finding very difficult. HF transmitters
are not easily available and seem prone to minor problems. Also,
the physical size of the transmitter antenna makes it difficult
to mount in a satellite buoy.
II11:portant considerations in optimizing the ra,nge and
directional sensitivity of the VHF system are the duration and
frequency of transmission, the proximity of metallic objects and
the height of the receiver antenna above sea level; power output
and antenna wavelength appear to be less important on the basis
of these test results.
With the duty cycle at 200 msec/sec rather than 100 msec/sec
the rece i ver holds the signal longer and is not so eas ily drawn
off by outside radio interference.
Attaining sufficient height
off the water and remaining clear of other objects is easily done
by mounting the antenna either on an existing mast on the ship or
constructing a simple pole for this purpose.
Varying the power
output of the transmitter from 0.25 to 0.4 watts, as demonstrated
in test #4, results in no significant differences in terms of
directional
sensitivity. Although the signal was stronger for
I
the transmitter with the higher power output, the directional
capability diminished equally at the same range of 12 n.m.
Likewise, the difference between 1/4 and 5/8 wavelength antennae
was not significant.
The Novatech DR400 is a compact, light weight and easily
operated receiver (see Fig. 5).
It can be hand held or mounted
readily at any point and it received the signals from the buoys
at the farthest range tested.
Also, the possible 180 0 ambiguity
in the bearing was easily resolved at all times when a direction
was obtained. Given the above mentioned transmitter and receiver
parameters, ranges of 12 n.m. can be easily obtained.
The Polaris Regency scanning receiver once mounted properly,
is a convenient and reliable way for the tracking of a beacon
from inside the bridge of any vessel. In view of our transmitter
power, the maximum range reliability seems to be 5 to 6 n.m. for
this receiver.
The difference in attainable ranges between the
two receivers appears to result from the fact that the Polaris
antenna is always scanning through 360 0 , where as the Novatech is
directional and searching can be concentrated in a more limited.
16
range of directions.
For the final test, the Novatech RF200 transmitter and
antenna was fitted inside a Hermes drifter buoy, alongside the
existing electronics and antenna with no modifications necessary
(see Fig. 6).
The OAR UHF receiver is a bulkier receiver which is more
difficult to operate than the others tested, although it has the
advantage of "homing in" on the drifting buoy, without the aid of
an additional transmitter, by internally storing the received
signal ?f the buoy itself an~ indicating the directional bearing.
An add it ional advan tage to the UHF 335 is that if the
situation arose where originally one had not intended to recover
the drifter, and therefore it was not equipped with VHF
transmitters, one could use the OAR ADF335 for recovery.
The
most prohibitive factor of the ADF335 unit is the cost, being
more than twenty times the cost of the Novatech receiver.
However, if program size warranted and recovery rates were
sufficient, the unit could be cost effective.
For most projects, where limited numbers of drifting buoys
are used,' the VHF system would be preferred due to its much lower
initial cost, greater operational range, as well as the ease, in
terms of availability and cost, of providing of back-up system. A
further consideration in favour of the VHF system, is the
portability of the receiver unit, allowing moving to near-shore
areas in a launch, where the ship could not operate.
In addition,
the VHF operation of the receivers is simple and can be quickly
explained to anyone whereas the UHF receiver requires much more
detailed instruction as to its operation. However, the use of the
OAR UHF system could be preferable in cases where large numbers of
drifting buoys are used, or in on-going programs where sufficient
useage is assured over the course of many individual projects.
Based on the observations of test #3, the presence of surface
waves may result in a reduction of the effective operating range
over which directional tracking is feasible.
In that test, with 4
to 5 foot waves present, the signal was modulated with a surface
wave frequency. However, further tests under a variety of wave
conditions, would be required to derive a quantitative
relationship between effective operating range and sea-state.
J.I
U.H.F. Antenna
O.4m
'. H. F. Antenna
f
r. H. F •
__-+--U.H.F. Transmitter
~ransmitt
Approximate Water Line
Buoy Hull
104m
Battery
Figure 6. Schematic of a VHF transmitter mounted inside a sattelite-tracked
drifting buoy.
18
Recommendations:
On the basis of the preceding tests, we would recommend using
VHF transmitters for locating and recovering free drifting buoys
in the ocean, given the ease of fitting a transmitter inside a
satellite-tracked buoy, the achievement of tracking ability out to
the required 10 n.m. range, as outlined in the introduction, the
simplicity of operating the VHF receivers, and their relatively
low cost.
The above recommendation is based on test results using a
Novatech RF200 radio beacon and a Novatech DR400 direction f~nding
receiver (see Appendix for specifications).
These results may
apply to VHF direction finding in general; however, potential
users should test other systems prior to beginning operations.
A coventional shipboard VHF receiver, the Regency Polaris,
NC7l00 (see Appendix for specifications), was found to operate out
to 6 n.m. with Novatech transmitters. This unit would serve as an
adequate back-up system to the better Novatech receiver.
In selecting a VHF tracking system, the following items
should be noted. The transmitter should be at least .15 watts,
although. going to higher output power doesn't necessarily mean
greater range, and should have a duty cycle of 200 msec/sec. Also,
care should be taken to choose a frequency, especially near land,
that avoids local radio interference as much as possible.
Depending on the expected life of the drifting buoy, extra
batteries could be placed inside the existing buoy without any
difficulty and/or a time delay switch could be placed in the
transmitter in order to extend battery life.
RUGGED & RELIABLE
BEACON FOR MARINE
AND LAND APPLICATIONS
BEACON +NUMEROUS OPTIONS
PROVIDES FLEXIBILITY AND VALUE
, __ •
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RF 200 RADIO BEACON
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·:~<l'l ~t~f~l~r~&:
ONE
•
Air droppable onto water.
•
Designed for Arctic use.
•
Compatible with numerous direction finding receivers:
Novatech, O.A.R., L- Tronics, Dorne and Margolin, Regencv
•
Replaceable "0" Cell Batteries.
';
. .'.;.
~ .
... ·i-:.',
•
Convenient On/Off Switch plus Indicating LED.
•
Available with Delaved Turn On.
•
Range; up to 50 km to an aircraft.
~
USES
•
Track oil spills, ocean currents etc.
•
Simulate oil spills.
•
Search and rescue Clperations.
•
Locate buoys, offshore platform, work sites.
•
Mark fishing spots and equipment.
fiI
Man overboard locator
.., Locdte
Illrid
survey
cl~ews
and eqlJlprnellL.
-
!\lOVATEC~
DESIGNS L TO.
... ' '.'
.. .
"
.
..:
PECIFICATIONS
•
•
•
•
•
•
•
TraJsmitter Power: 100 MW D.C. Output.
Transmitter Output Signal: pulsed C.W.
Transmitter Duty Cycle: 25%.
Batteries: 4 alkaline ·'0" cells (easily replaced).
Battery life: 10 days @ 4°C.
Operating Temperature Range: -50°C to +60o C.
Frequency; 6 channels starting at 150.815 MHZ (other VHF
channels available!.
• Antenna: Replaceable
• Materials:
1/4
wave whip.
Case -
Anodized Aluminum 6061 - T6.
Oelrln
Floatation Collar - Ethafoam
Capc-~
• Dimensions:
Case -
4 cm Diameter,
38 cm Long
(excluding antenna)
Floatation Collar -
• Weight:
680
10 cm Diameter.
14 cm Long
Grams excluding batteries.
JPTIONS:
A
B
C
o
E
Oil Tracking Skirt. Attaches easily
tracks ali and also
functions as a parLlchute fOI' ZlIl' drops. 36 crn. Diameter'.
Tilt Power Switch. BeCleon stol'ed Illverteu ....:.. power' on when
'·Ighted.
5/B Waue Antenna. 1 14 crn long Lllltenfld !J1'ov!ues !llcr'easerJ
I'd ng E:
lithium Batteries. R2cornrnemied TOJ' ·ow ':ernce"CltuI'e
apfJilcCltlons.
Delayed Turn On. Oelays tum on of beacon uo to 200 days No
II·udltll:LltIOII to b~(Jcull I'equweu. BeiJCOI1'S 4 batter'les replaced
v'JlUI 2 Ilthlull1 cells -_. OeiuyetJ tur·n url Ui1lt !r'stJils in place ui' the
OPERATION:
n::~et push button stc.lI'ts timing cycle
- beacon tums ON fOl' 24 tluur's thell shuts off.
elIte,· >.Jr·eset cJe!Ll'y' LJt..;uUlll tUI·ns ON ,,110 stays on.
SfJECIFICA T!ON
Ddu'! dUlustiJble fr·UIll <4 to 200 days In 2 day Increments.
Al~UJ['ClC'{. 1: 6 tiOl!!"S lJVt~I' c8!l1pef'Cltlll·e f'dfllJe -2 Ij')C to ~ilO°C
8t::dcun Bdttery Lde Apw;·ux 20 da'!:: fi!!"PC (exUd CiJUdCltY. due
to IlthlUl1l ceils)
Olillensiuns: 12 ern x J crl)
-
f -
,~ange !f1 '1190 seas and
'Ntlen woc·klng to a bOLlt. 8edeon dttaciles to ~oo of Dole - lJeacQn
's well up frorn water slJf"fdCe, aporux 100 en:.
Extension Floatation Pole: improve::
1
~ TA SHEET NO 550;
MADE IN CAf'JAOA
JUNE. 1980
I
I
I
~
I
NOVATECH DESIGNS lTD.
._----)
DESIGNS LTD.
RADIO DIRECTION FINDING SYSTEM
HRECTION FINDING RECEIVER DR 400
INTRODUCTION
The DR 400 is a compact portable direction finding receiver designed to locate VHF
transmitters. The receiver can be used from aircraft, boats, and vehicles, or hand-held
with a folding antenna. The direction to the transmitter is indicated by a left/right meter.
This method provides a simple and accurate means of homing in and approaching
within metres of the transmitter.
SPECIFICATIONS
type: dual conversion superhet, crystal controlled
channels: 4
D.F. sensitivity (useable): 1.5 uV or better
D.F. accuracy: 3 0
D.F. indication: meter, left/right steering or signal strength, no 1800 ambiguity
operating temperature range: -30 0 C to +60 0 C
audio output: 0.5 watts
dimensions: 9 cm by 11.5 cm by 5 cm deep
weight: 0.9 kg.
power: internal 9 volt batteries
battery life: up to 40 hours
enclosure: aluminum, weatherproof
OPTIONS
ANTENNA
01 - portable collapsible antenna, hand held
02 - two 1/4 wave whip antenna for aircraft or vehicle
03 - weatherproof antenna for boat or permanent land installations
RECEIVER DR 1200
- 12 channels
- waterproof version
internal batteries
- battery life: up to 100 hours
)ATA SHEET NO. 550; JANUARY 1980
NOVATECH DESIGNS LTD.
- - - -_ _ _ _ _ 822 Cormorant SI. Victoria. B.C. Canada V8W 1R1
MADE IN CANADA
(604) 381-1121
A TOTALLY UNIQUE CONCEPT IN MARINE
DIRECTION FINDERS. THE DIGITALLY
SYNTHESIZED, COMPUTER CONTROLLED NC7100.
Imagine being able to pinpoint to any VHF marine signal you hear in
only '12 second. The Polaris NC7100 permits precision direction finding capability once associated with only the most costly electronic
equipment. The reason centers around a circle of 36 yellow light emitting diodes (LED's). They scan until a VHF signal is received ... then
they point to the relative position of the transmitter. One LED gives
you ±5° accuracy. Two adjacent lights alternately flashing indicate a
more accurate bearing. This makes getting a bearing on coastal
VHF stations simple. Or by fixing on two known transmitter locations you can find your own position. You can even cruise toward
another ship by steering in the direction of the little yellow LED.
The Polaris NC7100 is finger touch controlled with all function
digital display and features a backlighted controlled board, all U.S.
or international signal switch, Channel 16 Priority, DF Hold
Switch, four weather channels and Reversible Mounting Capability
to make it applicable to virtuaHy all electronics configurations. A
special switchable dipole array antennf! is included.