106. Telegram From the Embassy in the Soviet Union to the Department of State1

11713. Subject: Probable Penetration. Ref: Moscow 11684.2

1. Antenna appears to be a modified 3 element Yagi (similar to Soviet TV antennae) directed in a north easterly direction. Polarization is vertical.

2. Antenna is located approximately at the top of the seventh floor inside the chimney.

3. Antenna feeds a white box about 4” x 2” x 10” that is probably a preamp since “12V” is clearly visible.

4. Second white box about 3” x 1½” x 6” is taped to above box and may be a combining network.

5. Other writing visible is “1361XOJ” and “N003.”

6. Antenna has been left in place and cables are intact. It has been secured by lines and steel bars to preclude attempt at recovery by opposition.

7. Chimney shaft may include multiple cables at lower levels that appear to enter both the Embassy and Soviet building. Cables continue down shaft and enter Soviet building at basement level.

8. We will soon enter shaft to inspect lower suspected cabling.

  1. Source: Carter Library, National Security Affairs, Staff Material, Office, Unfiled Files, Box 152, USSR: Technical Penetration of US Embassy in Moscow: 5–6/78. Secret; Immediate. Sent via the SY Channel.
  2. Telegram 11684 from Moscow, May 25, describing the technical penetration, is in the National Archives, RG 59, Central Foreign Policy File, [no film number].