synchronizer employing a war-surplus Bendix size-10 selsyn resolver for phase-shifting purposes. Rogoff's original noise wheels were retained for the transcontinental tests, as was his photo-optical multiplier, although the multiplier was improved to handle both positive and negative inputs. Using ionospheric prediction charts, transmission was near the maximum usable frequency (where multipath is least), in the 12-20 MHz range, without FCC license. The system bandwidth was fixed at 8 kHz, the data rate varied down to a few bits per second, and the transmitter power was adjustable between 12 and 25 W. Although documentation of the test results has not yet been made avail- able, Whittle recalls that during a magnetic storm that happened to occur, a 50 kW Mackay transmitter could not communicate with the East Coast using its conventional modulation, while FTL's test system operated successfully on 25 W. Often the noise-wheel system communicated reliably, even while interference in the same frequency band was provided by the high-power Mackay transmitter. Air Force observer Thomas Lawrence, Project Engineer on Della Rosa and Chief of the Deceptive Countermeasures Section at The Historical Origins of Spread-Spectrum Communications WADC (another WADC team member was Frank Catanzarite), also recalls witnessing these capabilities. However, some problems were encountered. In addition to the FTL sys- tem once being detected out-of-band (probably in the vicinity of the trans- mitter), propagation effects apparently caused trouble at times. The signals received at Telegraph Hill were preserved by a speed-lock tape recorder which had been built from scratch to have adequate stability. In the months following the transcontinental tests, John Groce performed correlation recovery experiments on the taped signals, experiencing considerable diffi- culty with multipath. Government-decreed project isolation prevented Rogoff from being told about the above tests of his noise wheels. In fact, Rogoff could not follow developments afte