'C', Chief of the Secret Intelligence Service (SIS): Wireless Communications; Budapest

A file of correspondence concerning the establishment of a wireless transmitter in the British embassy in Budapest, and a similar arrangement in the Hungarian embassy in London. The letters include arrangements for the installation of the equipment and funding of its use; discussion of the purposes for which it will be used; the search for a transmitter operating from a foreign embassy in London, eventually discovered to be the Hungarian legation; a record of a meeting with the Hungarian ambassador at which he admitted the existence of the radio set; and the details of a reciprocal agreement under which both the Hungarian embassy and the British embassy in Budapest could continue to operate their sets.