The Secretary of State to the Ambassador in Mexico ( Daniels )
Sir: The Department refers to your despatch No. 2441 of April 10, 1935, relating to the problem of interference in the amateur frequency bands 3500–4000 kc, 7000–7300 kc, and 14000–14400 kc, as the result of the operation in these bands of amateur radiotelephone stations in Mexico, and advises you as follows concerning this matter.
It appears from the despatch that the Mexican Minister of Foreign Affairs advised your Embassy that “the competent authorities have [Page 811] decided to accept the proposals made by the Federal Communications Commission of the United States relative to the distribution of amateur frequency bands”. From an examination of the table of frequencies submitted by the Mexican Minister of Foreign Affairs it would seem that the Mexican authorities misconstrued the suggestions of the Federal Communications Commission since they have sought to restrict the Mexican amateurs to channels permitted by the Madrid convention which did not conflict with the channels used by American amateurs, but which do, however, in some instances, still conflict with the frequencies 3500–4000 (3700–3900), 7000–7300 (7150–7300), and 14000–14400 (14075–14150). Moreover, no reference was made in the Mexican note to the Commission’s suggestion that “only type A1 emissions be permitted in the bands 3500–3900 kc, 7000–7300 kc, 14000–14150 kc, and 14250–14400 kc.
In view of the foregoing in transmitting a copy of your despatch to the Commission the Department requested an expression of its views with regard to further possible action that might be taken in this case.
The Department has now received a reply from the Federal Communications Commission, a copy of which is enclosed herewith,75 and it is suggested that, if you perceive no objection to such a course, you take up this matter again with the competent Mexican authorities. In taking this matter up with the Mexican authorities you should express this Government’s appreciation of the friendly spirit of cooperation shown by the Mexican authorities and express regrets that through an apparent misconstruction of the suggestion of the Federal Communications Commission radio amateurs in Mexico may have been inconvenienced. Briefly stated, the suggestion of the Federal Communications Commission is that amateur radiophones, both in the United States and Mexico should only operate on the following frequencies:
- 1800–2000 kc
- 3900–4000 kc
- 14150–14250 kc
- 28000–28500 kc
- 56000–60000 kc
- 400000–401000 kc
And, secondly, that only type A1 emissions be permitted in the bands 3500–3900 kc, 7000–7300 kc, 14000–14150 kc and 14250–14400 kc. It will be observed from the foregoing that the Federal Communications Commission did not suggest that amateurs in Mexico should not operate on the same frequencies as amateurs in the United States, but that both in the United States and in Mexico amateur radiophone operators should operate on certain given frequencies which are listed above. The Department trusts that with the added explanation the competent Mexican authorities may see their way clear to adopt the suggestion of the Federal Communications Commission which can only redound [Page 812] to the advantage of amateur radiophone operators both in the United States and Mexico.
Very truly yours,
- Not printed.↩