Radiobeacon System Map for North Atlantic (1943)

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
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
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
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
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 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 3-6 Montauk Point Lighthouse Yes C 41 04.3 71 51.4
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
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
 1 Operates for calibration only. Will not operate when Ambrose group is in operation.