ASPECTS OF COMMUNICATIONS 145 



The four cameras furnished Sealab were duplicates of the ones designed for use in Benthic, 

 with the exception that the Sealab cameras were not equipped with remotely operated pan/tilt 

 mechanism, as were the two cameras used in benthic. 



Three of the four video coaxial connections to benthic, along with telemetered signals for 

 focus and sensitivity adjustments, were lost during the initial benthic -to-Sealab hookup as a 

 result of the cable-connector damage. 



Both cameras installed inside Sealab functioned normally and transmitted acceptable pic- 

 tured ashore via benthic, when either was connected through the one existing good video channel. 

 Focus and sensitivity adjustments were made using a jury-rig substitute in Sealab for the lost 

 control functions. 



The two underwater cameras outside of Sealab were never lifted out of the mud for testing, 

 presumably because there were no additional video channels available for their use, and be- 

 cause the limited visibility in the surrounding water discouraged their use. 



Both inside cameras remained operable throughout the 42 days of operation, but they be- 

 came less and less usable as a result of many holes burned in the vidicon targets by the fre- 

 quent flashing of flash bulbs by photographers in Sealab. It is believed that the vidicons were 

 vulnerable because of the low heat-absorption characteristics of the Lucite lens. A piece of 

 heat-absorbent glass was taped over the front of the lens of the one camera in use during the 

 closing days of the operation, and no additional burns appeared. 



On shore at benthic control, TV carriers were boosted and distributed to various offices 

 in the headquarters building and to Sumner auditorium, where they were viewed by officials of 

 the project, the press, and the public on standard commercial home entertainment-type TV 

 receivers. 



During the operation, additional TV video signals from cameras supplied by Oceanographic 

 Engineering Company were brought ashore via separate coaxial cables laid to the Berkone. 

 These cameras did not perform satisfactorily in the Helium atmosphere, probably due to helium 

 leaking into the case, causing overheating and detuning. The same type of cameras, placed in 

 the water outside the habitat looking through the ports into the habitat, performed well, and 

 were used as the primary monitoring cameras during the last half of the program. 



Support Vessel Television - Two industrial TV tuners were located in the command van. 

 Coaxial cable was run from these to various locations throughout the vessel and to monitors 

 which could be switched to either tuner. 



CONCLUSIONS 



Before pressurizing Sealab, the Aquasonic units aboard were opened to ambient pressure 

 to ensure that the batteries could be changed at 200 ft. It is felt that pressure on the com- 

 ponents had some effect on the intelligibility. Transmissions between support vessel and Sealab 

 via Aquasonic were somewhat garbled, but this may have been partly due to the thermocline. 



The Bioengionics mask that was used had straps connecting it to a hood. It was impossible 

 to get a tight seal sufficient to prevent gas loss around the edges. The back pressure of the 

 Mark VI scuba makes a tight seal imperative. 



The wire-type intercom used a bone-conduction microphone. It was felt that pressure on 

 this unit deformed the sides such that the frequency response was severely limited. To verify 

 this, a test recording was made in a chamber at 200 ft using the bone phone. The recording 

 showed that the increased pressure did limit the frequency response, but not enough to account 

 for the distortion noted in Sealab n. 



The present Navy helium speech unscrambler did not provide continuously reliable and 

 improved intelligibility, due to either equipment malfunction or maladjustment. 



