CO129-498-1 Indepartmental conference on Piracy- report 12-1-1926 - 20-4-1926 — Page 78

12

APPENDIX II—cont.

FOREIGN WATERS TRIAL HOMEWARD VOYAGE.

Radio

Distance.

Record.

Marconi. Communi.

cation Co.

Number of tests

639

650

Number correct

545

559

Power

Number of failures

94

Over 75 miles.

91

Percentage of failures

14.7%

14%

Number of tests

51

50

Number correct

28

22

Emergency

Number of failures

23

28

Percentage of failures

45.1%

56%

Number of tests

534

522

Number correct

494

Power

503

Under 75

Number of failures

40

19

Percentage of failures

7*5%

3.6%

Number of tests

232

miles.

245

Number correct

184

183

Emergency

Number of failures

48

62

Percentage of failures

20.7%

25·4%

Not stated.

Power

Number of tests Number correct Number of failures Percentage of failures

---

4

2

3

1

50%

25%

At all ranges.

Power and

Total number of tests... Number correct

1,460

1,471

1,253

1,270

Emergency Number of failures

207

Percentage of failures

14.2% approx.

201 13.6%

Number of false calls

0

1

13

APPENDIX III.

INSTRUCTIONS ISSUED TO WIT STATIONS BY G.P.O.

29th January, 1924.

The Officer-in-Charge,

Wireless Telegraph Station.

Trial of Automatic Device for Recording the Distress Signal.

៩:

1. The s.8.

Rathlin,

,"call sign GFMC, running between Glasgow and London, has been equipped with certain apparatus for the purpose of ascertaining if a signal can be found which will give reasonably good results over an adequate range in spite of interference.

2. Two signals have been adopted for trial:—

(a) A long dash of 15 seconds.

Three dashes of four seconds separated by an interval of

one second.

3. Three sets of apparatus are employed in the trial :-

(a) Post Office long-dash device (a) above.

(b) Marconi 4-seconds dash device (b) above,

(c) Radio Communication's 4-seconds dash device (b) above.

4. The ship's equipment will be worked by a naval staff under naval supervision.

5. The procedure will be as follows:-

The s.s.

Rathlin,' on coming within suitable range of a Post Office coast station, will call the station and make the signal QZZ, which will indicate-

"Send a series of fifteen-second dashes each dash followed by a space of five seconds for one minute followed after an interval of 30 seconds by a series of 4-second dashes each dash followed by a space of one second for one minute followed by the call signal of the station. These signals should be sent out once every hour at your convenience until you receive a signal Annul QZZ' from me indicating that the test is over for the time being."

Scale one minute first minute programme

thirty seconds pause

second minute programme

6. In order that two adjacent stations shall not accidentally

signal at the same time--

Portpatrick Fishguard

Niton

will send their signals between 0 and 30'.