NMT.
Paper for discussion at Policy Committee, 30. 5. 40.

Question of B.B.C. Reprisals .

Sir Noel Ashbridge asked me last night what would be the Government's policy on the question of reprisals, i.e. jamming in return for being jammed.

He made the following points:

(1) At present we use only two wave-lengths (by mid-June, or a little earlier we shall be using a third). This makes us an easy mark for the Germans, who need only use the two powerful Dutch’ stations of Hilversum and Jaresfeld (and a third from the neighbourhood) to put our transmitters completely out of service as a means of communication to Home listeners.

It seems necessary to assume that, if the enemy does not destroy our stations by bombing, he will jam our broadcasts, with a view to denying us the means of communicating by wireless with our own listeners.

(2) The objections to jamming on our part at present are:-

(i) that it leads to reprisals, in which we stand to lose more than the enemy, because our broadcasts enjoy greater credit than his;

(ii) that he probably has more stations than we, so that in the end he might be left with a clear surplus;

(iii) that, in time of air-raids, jamming gives just as much D.F. help to the raider as an intelligible broadcast. (Note that while it would be possible to jam effectively on a synchronised system, without D.F., we haven't enough transmitters to jam more than two or at most, three stations in this way).

(3) In the conditions in which we are assuming that reprisals would be urgently needed, air-raids will probably be taking place, so that objection (iii) may be very serious, from the point of view of the Air Staff.

(4) It is probably too much to ask the Cabinet now to reach a decision on principle in what is at present a hypothetical case. It is however desired by the B.B.C. that the attention of the Minister should be called to this problem, and that he should be asked to decide now whether the B.B.C. should proceed forthwith to draw up plans for the application of reprisals in an agreed form in time of crisis, and to incur preliminary expenditure on research and other necessary precautions. (The amount to be spent would not be large).

(5) It is recommended that the B.B.C. should be told to proceed on these lines. The Cabinet might then have their attention drawn to the problem by the Minister, with the warning that in an emergency he may have to ask them to decide at very short notice what should be done.

(6) Two forms of reprisal must be considered:

A. To re-open all our pre-war stations (eight or nine in all), and transmit from all simultaneously on separate wave-lengths. This would make it more difficult for the enemy to jam us all, and we might succeed in getting a message from one or two of them heard intelligibly. (Note that successful jamming is best accomplished by emitting a spoken message rather than a mere noise; we should certainly do this, with the double object of achieving a more successful jam, and of getting our message heard),

B. To re-open only as many as are required to jam the enemy effectively.

A is obviously preferable from our stand point, and may be no worse from that of the Air Staff.

(7) We should use our transmitters to jam the most widely-heard. German Home Service long-wave transmitters - Deutschlandsender and four or five [illegible] It should he quite effective.

(8) To do all this would mean abandoning our own medium-wave overseas Service entirely, reconverting Droitwich to long-wave, and leaving only the short-wave overseas. But in the circumstances envisaged we should no doubt be prepared to make this sacrifice,

B.B.C. representatives would like the matter discussed at Thursday's Policy Committee.

A.P.W.

Deputy Secretary.

28th May, 1940.