142 ASPECTS OF COMMUNICATIONS 



Helium Speech Unsc rambler 



The helium speech unscrambler was provided by the Naval Applied Science Laboratory in 

 cooperation with BuShips. Three headsets were provided and were located in the Sealab com- 

 munication center, galley, and berthing area. Conductors and connectors are listed in Table 3. 

 Unscramblers were located on the support vessel and on shore. The shore unit did not improve 

 the helium-speech distortion. The support-vessel unit was used intermittently and was consid- 

 ered by some to be marginal. During the visit of Mr. Copel of the Applied Science Laboratory, 

 the adjustment of the unit improved the voice materially. Such improvement was not generally 

 experienced. 



Electrowriter 



The electrowriter, consisting of a transmitting and receiving unit, was provided by the 

 Mine Defense Laboratory and installed by the Naval Ordnance Test Station. Conductors and 

 connectors are listed in Table 3. 



Television 



The TV units for monitoring and entertainment were furnished by Scripps Institution of 

 Oceanography. Conductors and connectors are listed in Table 3. 



Audio 



The audio link for two-way communications from the support vessel to Sealab was a Bogen 

 commercial intercom system. A two- station master was provided for the communication van 

 on the support vessel with a remote unit in Sealab. A headset which was compatible with the 

 master station was provided for the Sealab communication center. A two-position selector 

 switch was provided on the patch panel to permit the selection of the speaker or headset. A 

 momentary contact switch was provided as press-to-talk switch to permit the speaker to be 

 used as a microphone only when using the headset. 



Wedge Spirometer 



The wedge spirometer was furnished by the Submarine Medical Center and installed by the 

 Naval Ordance Test Station. An extension cable with appropriate plugs on each end was in- 

 stalled from the communications van to the atmosphere control van. 



O2 Partial Pressure 



The Krasberg unit for determining the O2 partial pressure in Sealab was furnished by 

 Westinghouse. Provisions were made to monitor and record the O2 partial pressure remotely. 



Equipment Mounting Strips 



To facilitate the installation of communication and monitoring equipment during the fitting- 

 out period, two slotted metal angle strips were installed on the overhead on the surface of the 

 cork insulation in the lab, galley, and berthing spaces. The strips were approximately 2 ft 

 2 in. on either side of the center line and ran the entire length of each space, except where in- 

 terference existed. 



In addition to the systems discussed in the foregoing, which were incorporated in the um- 

 bilical cord, two acoustic voice communication systems were provided between the support- 

 vessel diving platform and the habitat. The two systems were (a) a Navy submarine voice com- 

 munication system, AN/BQC and (b) an Aqua-Sonics voice communication system. Because of 



