We are presently using a completely trans- 
istorized buoy operating on 6970 kiloycles for 
our long range oceanographic telemetry. This 
buoy, manufactured by Concord Control, Inc. of 
Boston, is some thirteen feet long and eight 
inches in diameter. The bottom plate is two 
feet in diameter made of bronze, and acts both 
as a ground and as a vertical motion damper. 
The case is fiberglass or polyvinyl chloride. 
The electronics are built in modules which plug 
into a rack frame four feet long attached to 
the top plate. Figure 1 shows this rack. The 
top plate contains the antenna base insulator, 
tuning meter and necessary tuning and loading 
controls. The batteries, located in the bot- 
tom portion of the case, are LeClanche cells 
packaged in an eight inch cylinder three feet 
long. The receiver is a more or less standard 
crystal controlled super-heterodyne whose out- 
put drives two resonant reed relays. These 
relays, through special delay circuitry ener- 
gize command function relays. Three interroga- 
tion command functions are thus possible, one 
or the other resonant reed relays or both 
simultaneously. Once interrogated, a timer is 
activated which causes the transmitter either 
to send out its call sign or a data transmis- 
sion, depending upon the function chosen. The 
transmitter supplies 30 watts of power to a 
center-loaded marine type whip antenna. We 
have been using frequency-shift keying with a 
nominal shift of 240 cycles in our experiments. 
I would like to discuss a recent experi- 
ment which was designed to determine the 
feasibility of 1) the modest power output 
2) the 7 mc. frequency chosen, and 3) the FSK 
mode of operation. Accordingly a tract of 
land in Waquoit, Massachusetts (twelve miles 
from Woods Hole) was leased, and a beam anten- 
na for 6970 kc. erected. A communication van 
housing receiving equipment, discriminators, 
and a tape recorder, was installed at the base 
of the antenna as shown in Figure 2. This 
receiving site proved excellent from a noise 
standpoint. The beam constructed was a three 
element array with parasitically excited re- 
flector and director. Subsequent field pattern 
tests run with the aid of our Helio Courier 
aircraft acting as a signal source, established 
the major lobe at 140 degrees true, the direc- 
tion desired for our tests. The front to back 
ratio was better than 15 db. and the horizon- 
tal beam width about 80 degrees. A Concord 
buoy, like the one just described, was taken 
to sea and put in the water at intervals. 
Measurements of signal strength and readabil- 
ity were then made at Waquoit. Because of the 
small number of transmissions, we are unable 
to present reliable statistics, but we can 
make certain generalizations of the results. 
The buoy was put overboard and allowed to 
drift away from the ship about a thousand feet 
and interrogated from the ship. A typical 
picture of the buoy in the water is shown. 
51 
It was put over at different times of day and 
at ranges between 200 and 140U miles from 
Waquoit. At least 50% of the transmissions 
were received at each range at Waquoit well 
enough to retrieve data regardless of time of 
day. Obviously this modest percentage is 
greatly weighted by the fact that some of the 
tests were run at the most adverse times of 
day, as far as propagation was concerned. At 
optimum time of day, the percentage was better, 
and by providing some sort of redundancy, we 
feel that we can have a reliable link. We 
believe that low power, high frequency FSK 
transmissions can be practically utilized 
for oceanographic telemetry, assuming that 
the optimum time of day be utilized, and that 
interrogation techniques be used. The inter- 
rogation technique allows repeat of transmis- 
sions to allow data redundancy during periods 
of high noise or interference. The data rate 
was 10 bits per second during these tests; 
however we anticipate rates of up to 100 bits 
per second. 
CONCLUSIONS 
The serial observation of oceanographical 
data from buoys located at certain remote 
sensitive areas of the ocean can in many in- 
stances supply the oceanographer with informa- 
tion not otherwise obtained. A monitor of this 
sort might provide a warning of some specific 
change, or it might indicate a trend whose 
correlation with other data ashore proves 
valuable. 
What of the 
telemetry systems 
immediate future as far as 
are concerned? We feel that 
regardless of the admittedly higher data hand- 
ling capabilities of the VHF bands, the line 
of sight limitation imposes too heavy a burden 
on auxiliary equipment to make it an immediate 
solution to the long range telemetry problem. 
If and when there are hundreds of buoys in the 
water, satellite relaying or data collection by 
high-flying aircraft may be worthwhile, and in 
fact necessary because of problems of frequency 
allocation, but if we were to start now to 
design a system of more modest extent for use 
in a given ocean area, there is no doubt in our 
minds that the high frequency bands will be 
utilized. 
For example, Richardson's buoy line 
between here and Bermuda is presently recording 
at about ten buoy stations, and as far as we 
know, it is the only area now being monitored 
by a whole system of buoys for scientific pur- 
poses. Presumably it is well worthwhile to 
maintain this line more or less indefinitely, 
and as soon as the telemetry can be as reliable 
as the recording apparatus, and the platforms 
can maintain themselves reliably for six months 
or more, it will undoubtedly be more desirable 
