than the German tubes used at that time; the imported tubes had a life of 25 to 30 hours. DuMont's invention of the first long-lasting cathode ray tube would later make commercially viable television possible. He started his own company, Allen B. DuMont Laboratories, in the basement of his Upper Montclair home, building long-lasting cathode ray tubes. In 1931, he sold two tubes to two college science laboratories for $35 each. Since DuMont was a leader in cathode ray tube or CRT design and manufacturing, it was a natural step to use the CRT as a visual measuring instrument or oscilloscope. The production of CRT's and oscilloscopes was part of DuMont Laboratories located in Upper Montclair, NJ. Needing more space he moved to a larger location in Passaic, NJ in 1934. Although not the inventor of the oscilloscope, DuMont designed and mass-produced practical oscilloscopes (he called them oscillographs) for all types of laboratory, automotive/equipment servicing and manufacturing applications. By the 1940s DuMont was the leader in the oscilloscope equipment market. DuMont was one of the earliest designers of the trigger sweep oscilloscope using a gas thyratron vacuum tube (forerunner to the silicon controlled rectifier or SCR). This allowed the oscilloscope to show a visual trace at a preset input signal level. In addition the sweep (trace across the CRT screen) could be regulated by the sweep speed or sweep frequency. This design allowed the oscilloscope to provide better visual detail of the measurement being studied. The trigger was a frequency synchronizing type which provided stability in viewing. The profits from the oscillographs helped him invest in television design and his DuMont TV Network. Unfortunately the time spent on his TV ventures proved to be the end of his profitable oscillograph business. In 1947, a young equipment manufacturer called Tektronix produced the model 511 Time Base Trigger and Sweep Oscilloscope for $795. The use of time instead of frequency to measure a sweep across the CRT was Tektronix's big selling point. Time measurements are easier to interpret pulses and complex waveforms. It has been mentioned informally that Allen DuMont saw the model 511 demonstrated at an electronics show. He tried it and was impressed, but commented to Howard Vollum and Jack Murdock, co-founders of Tektronix that it was too expensive and they would be lucky to sell any. Tektronix's time base trigger and time sweep generator design would become the standard