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Spectrum Management - From the Early Years to the 1990s |
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Page 11 of 26 Spectrum Surveillance and Monitoring - Early years |
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Monitoring
To measure radio waves, we had to receive them first!
from the Radio Times, December 19, 1924
The very first radio stations of the Radio Branch were established to communicate with ships in Hudson Bay as early as 1927. The main station was in Ottawa and others were at Port Burwell, Cape Hopes Advance, Nottingham Island, in Chesterfield Inlet and Churchill.
"-- the receiving station was off the end of a green house in the Arboretum. Due to
the excessive humidity and general unsuitability of the greenhouse, C.P. Edwards
obtained permission from Dr. Archibald, then director at the CEF, to use the
unoccupied side of the old T.R. Booth farmhouse still standing near the corner of
the Base Line Road and the Prescott Highway. Since the VAA receiving station
occupied one room only, the powers that were decided to move the frequency
standard from the Test Room and make the fullest use of the VAA receiving
operator to operate the equipment in his spare time." "The first frequency standard operated by the old Radio Branch of the DM&F that I have
recollections of seeing in approximately 1932 was a Sullivan Fork operating at 1000 cps
(hertz/second). The temperature control system for the fork chamber depended on the expansion
of toluol confined in a fairly large glass tubular helix. After several "flareups", the system was
condemned as being rather crude and a decided fire hazard. I do not believe it was ever
successfully operated. The original Radio Test Room was on Wellington Street, Ottawa, about where No. 3
Temporary Building now stands. The test room was the responsibility of J.W. Bain who had
entered the Radio Branch from a lecturing professorship at Queen's University. He worked
under A.N. Fraser, Chief Engineer and C.P. Edwards, the Director.
The purpose of the Sullivan Fork was not for measurement of remote signals but rather for
the calibration of wave meters which were in use in the district offices for the adjustment of
transmitters ashore and afloat, a number of which were still of the "spark" variety. Some time later, perhaps a year or so, Mr. Bain was successful in obtaining funds to purchase
the first General Radio (GR) Primary Standard of Frequency, developed by J.K. Clapp who
was the son of the elder Clapp of the old Clapp-Eastham radio firm in the New England
States. This frequency standard was based on a 50 Kc Piezo Bar, with two stages of mercury
thermostatic control. The frequency division was to 10 Kc and 1 Kc intervals as well as 50 Kc
by the use of multivibrators each using filament type tubes (20lAs I believe). Bias voltages were from C batteries which always seemed to be going dead. Filament type
tubes were very critical to filament voltage - a drop of 2/10 volts often causing one or other
of the multivibrators to drop out, consequently, a week without interruptions was a real
achievement and required a good deal of "nursing" of the equipment. The measuring of audio frequencies was carried out using a Wien Bridge.
The receiving equipment was supplied by Canadian Marconi and consisted of TRF (tuned-radio
frequency) receivers covering from 100 Kc to 25 M/c which in those times was considered really
something! This equipment was installed in the second floor front room of the old Test Room. As the new GR standard was complete with receiving equipment, something could now be
done about the measurement of remote signals. This was confined to broadcasting stations, as
Mr. Bain was not proficient in International Morse, which injected the problem of identifying
telegraphic signals. Emission types other than Al or A2 (chopper undulated) were seldom
encountered, though several ships were still using spark. The Radio Test Room in Ottawa was located on Wellington. With the street cars in use at the
time, the resulting interference did not make life easy for a monitoring station. There were
many transmitters in the area, including the VAA transmitter which was used for
communications with northern stations, the Canadian Radio Broadcasting Commission
transmitter on the Jackson building, another one belonging to the navy at Rockcliffe and the
CHU transmitter for the Dominion Observatory time service. The workshop was therefore
moved to a greenhouse on the grounds of the Experimental Farm around 1934." That is how Ed Davey, after being the VAA station operator since that time, became the first certified
operator of the first monitoring station in Canada in October 1936. Ed continues: "The instructions were to measure, measure, measure. Frequency measurement was the main
activity and it wasn't long before the Branch's frequency equipment proved to be more stable
than that of the Dominion Observatory which was responsible for transmitting official time
signals. Thus the 1,000 hertz standard generated by the Centre was used to modulate the
CHU transmitters and (the modulated tone) served as the national frequency standard via radio. When the old Canadian Radio Broadcasting Commission became the CBC, Mr. Bain, after a
bitter controversy with Mr. (later General) A.G.L. McNaughton, was successful in his fight,
contending that it was the prerogative of the Radio Branch to engage in monitoring in
Canada since the Radio Act was being administered by us. The Branch was thus able to
obtain three General Radio Standards and numerous other receiving and auxiliary equipment
that the NRC used only for monitoring the frequencies of its own stations. Andy McNaughton had insisted that the equipment remain where it was, but this plant,
complete with buildings, was transferred to the Branch." At Strathburn, the Commission (CRBC) operated a monitoring station that was used mainly to
measure the frequencies of its own stations. These facilities became the Branch's second monitoring
station. "At the same time, there was enough equipment to establish one or two more stations on the
west coast and in the middle of the country. Part of the old equipment was later moved and
used to establish the Vancouver monitoring station. When Vancouver was re-equipped later
after the war, this old original standard was sent to the Victoria workshop to be used for
checking wave meters." Other old equipment used at the station at the Experimental Farm was recovered for
installing the first station in the West, at Rivers, Manitoba.
The crystal was a 100 Kc cube, mounted in a hammock formed of six very
fine silk threads which required careful tensioning. An earthquake of 6.2
with its epicentre in Temiscaming on November 1, 1935, shook the cube
out of its hammock and it required days of fiddling to get it remounted and
the silk threads correctly tensioned. The dial drives were belts made from a special fishing
line, procurable only in Devonshire in the United Kingdom. "Purchasing" always viewed with
dark suspicion the item of expensive trout line in a requisition for radio spares." About 1938, there were four stations, Ottawa, Vancouver, Strathburn and Rivers; a
fair expansion with always more hoped for in the future. I obtained full-time help
when Gerry Gard was transferred from the Saint John Inspection Office."
"At the outbreak of war, it was the policy of HQ that the monitoring
service would form the nucleus of an interception service in case of
war. In December 1939, I moved the Marconi 482-C equipment to Hartlen Point, Nova Scotia,
which was specially built (in 1935) for interception and DF work." The Hartlen Point site was on the east side of the Halifax harbour entrance and allowed a full view of
the ocean in all directions. There, staff carried out interception and DF work to obtain readings on the
positions of submarines and ships. All staff was from the Department of Transport, with operators averaging 11 years of experience.
Shifts consisted of four operators in rotation during the watch, with each one taking a turn at direction
finding. In late 1942, a total of 14 operators worked at this station, four of them for the DF equipment, and the
others using five receivers to intercept transmissions from German "U-boats". Ed Davey continues: "Mr. Bain - looking forward as usual - thought that getting a frequency standard installed there would be a "foot in the door" for the post-war years." (We would see later on that this foresight paid off.) "In 1939, the demands of Commander DeMarbois caused an increase in staff at the Ottawa monitoring station to a peak of 125 operators."
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Spectrum Management - From the Early Years to the 1990s |
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"At the beginning of World War II, the government edict was to "buy
Empire" if similar equipment for our needs could be obtained. This
temporarily prevented the purchase of equipment from the US, and so
we purchased a Marconi Type 482-C frequency standard (see No. 70 of
the "The Marconi Review", appended)
The Rivers station, 150 miles west of Winnipeg, had apparently been in operation since 1937 and
G.A. Coutanche was still the supervisor in 1957. Previously, there had been a station at Winnipeg,
specifically at Stevenson's Field, where the airport used to be. Because it had increased in size, it was
moved to Rivers.