Radiobeacon System Map for North Atlantic (1940)

Radiobeacon System

FREQUENCY is given in kilocycles.

CHARACTERISTIC is shown in combinations of dots and dashes.

UNITED STATES and CANADIAN radiobeacons are assigned group frequencies and definite operating minutes. The sequence within a group is indicated by a Roman numeral. Stations with the same sequence numbers transmit during the same minute.

The scheduled 10 minute periods out of each hour of clear weather are not displayed on the map but is shown in the table of sequenced radiobeacons. For example, a clear weather schedule of 1-4 indicates that the characteristic code is transmitted during the first and fourth 10 minute periods of the hour. The last minute of each clear weather 10 minute period is silent. (See clock face diagram on map for definition of each clear weather period.)

At the stations marked the radiobeacon and sound signal are synchronized for DISTANCE FINDING.

Radiobeacons marked are of low power for local use only. They operate continuously on the frequency and they have special characteristics as indicated for each case. The above notes relative to sequence, characteristic, and schedule do not apply to these radiobeacons.

The service range is a reliable average range as follows:

Class A: 200 Miles (150 to 250)

Class B: 100 Miles (50 to 150)

Class C: 15 Miles (10 to 20)

Class D (Marker Radiobeacons): 10 Miles (5 to 15)

Sequenced Radiobeacons

286	I	3-6	Ambrose	Lightship	Yes	etc.	B	40 27.1	73 49.4
286	II	3-6	Barnegat	Lightship	Yes		B	39 45.8	73 56.0
286	III	3-6	Fire Island	Lightship	Yes		B	40 28.7	73 11.4
288	I	1-4	West Quoddy	Lighthouse	Yes		C	44 48.9	66 57.1
288	II	1-4	Hen and Chickens	Lightship	Yes		C	41 27.0	71 01.1
288	II	1-4	Mount Desert	Lighthouse	Yes		C	43 58.1	68 07.7
288	III	1-4	Portland	Lightship	Yes		B	43 31.5	70 05.5
290	I	1-4	Cross Rip	Lightship	Yes		C	41 26.9	70 17.5
290	I	2	Smith Point	Lighthouse	Yes		C	37 52.8	76 11.0
290	II	2-5	Cape Henry	Lighthouse	Yes		C	36 55.6	76 00.4
290	III	2	Wolf Trap	Lighthouse	Yes		C	37 23.4	76 11.4
292	I	3	Eastern Point	Lighthouse	No		C	42 34.8	70 39.9
292	II	3	Cape Cod Canal Breakwater	Lighthouse	No		C	41 46.5	70 29.8
292	III	3	Nobska Point	Lighthouse	No		C	41 30.9	70 39.4
294	I	3	Point Judith	Lighthouse	No		C	41 21.2	71 28.9
294	II	3	Little Gull Island	Lighthouse	Yes		C	41 12.4	72 06.4
294	III	3	Scotland	Lightship	No		C	40 26.6	73 55.2
296	III	1-4	Sambro (Can.)	Lightship	No	Three times	B	44 21.8	63 25.8
298	II	1-4	Stone Horse Shoal	Lightship	Yes		C	41 32.8	69 59.1
298	II	1-4	Winter-Quarter Shoal	Lightship	Yes		B	37 55.5	74 56.4
298	III	1-4	Five Fathom Bank	Lightship	Yes		B	38 47.3	74 34.5
300	III	1-4	Manana Island	Fog Signal	Yes		B	43 45.8	69 19.7
302	I	2-5	Highland	Lighthouse	No		A	42 02.4	70 03.6
302	II	2-5	Boston	Lightship	Yes		B	42 20.4	70 45.5
302	III	2-5	Vineyard Sound	Lightship	Yes		B	41 22.8	71 00.0
306	I	1	Cove Point	Lighthouse	Yes		C	38 23.2	76 22.9
306	II	1-4	Overfalls	Lightship	Yes		B	38 48.0	75 01.4
306	III	1	Sandy Point Shoal	Lighthouse	Yes		C	39 01.0	76 23.1
308	I	1-4	Cornfield Point	Lightship	Yes		C	41 12.9	72 22.2
308	I	2	Western Head (Can.)	Fog Signal	No	Three times	B	43 59.3	64 39.7
308	II	1-4	Handkerchief	Lightship	Yes		C	41 29.2	70 04.0
308	II	2	Lurcher Shoal (Can.)	Lightship	No	Three times	B	43 48.5	66 31.8
308	III	2-5	Seal Island (Can.)	Lighthouse	No	Three times	B	43 23.5	66 00.9
310	I	3	Execution Rocks	Lighthouse	Yes		C	40 52.7	73 44.3
310	II	1-4	Brenton Reef	Lightship	Yes		C	41 25.9	71 22.6
310	II	3	Stratford Shoal	Lighthouse	Yes		C	41 03.6	73 06.1
312	I	1-4	Chesapeake	Lightship	Yes		B	36 58.7	75 42.2
314	I	2-5	Pollock Rip	Lightship	Yes		B	41 36.1	69 51.1
314	II	2-5	Nantucket Shoals	Lightship	Yes		A	40 37.0	69 37.0
314	III	2-5	Block Island Southeast	Lighthouse	Yes		B	41 09.2	71 33.1

Request for Calibration Radiobeacons

286	Coney Island1	Lighthouse		C	40 34.6	74 00.7

Marker Radiobeacons