George Frye

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George Frye

George Joseph Frye (? – ?) co-invented the random sampling technique.

George Frye grew up in Kansas City, Missouri and attended Rockhurst High School in Kansas City. After that, he attended Rockhurst College as a physics major. He transferred to the University of Kansas and studied electrical engineering. As an undergrad project, he built a carrier current system for the campus. During these early years, George was active on ham radio (W0EZU) and eventually worked all continents.

During undergrad, Frye worked at Wilcox Electric, initially in shipping, later on the assembly line, soldering, and later helping debug 10 kW shortwave transmitters.

As a grad student, also at the University of Kansas, under Professor Norris Nahman, he developed the random sampling technique under a grant from the US National Security Agency.

George writes:

“But then realized that an NSA project I worked on while going for my MSEE at KU showed the way to generate real time sampling pulses at very high frequencies.

Just use a klystron. Velocity modulate the beam at the desired sampling frequency and then place a catch electrode at the point where the electrons combine in pulses at the modulating frequency. Klystrons usually place a cavity there to collect the amplified RF signal.

That was the basis for the project I was assigned to 60 years ago…”

While still in Kansas City, he took a job at Bendix Corporation. That was work for the Department of Defense.

In 1962, he joined Norm Winningstad's sampling group at Tektronix. Their group was in a building on Barnes road. Later, they moved to the second floor of Building 50 on the Tektronix Campus.

George's first assignment at Tek was to build a high speed (around 100 MHz) square wave waveform generator for internal purposes. It didn't go into production.

After Norm Winningstad left Tektronix in the mid-1960s, George Frye's manager was Al Zimmerman.

Frye is listed as "Project Engineer, Electrical" on the 4S2A sampling plug-in for the 661. In the late 1960s, he was involved ("head man") with the development of the S-1 and S-2 sampling heads. The sampling technology used in those sampling heads was similar to previous instruments, just modularized.

In terms of making high speed sampling heads, Tek was at a disadvantage compared to HP because HP had faster snap-off diodes. This enabled HP to generate very sharp sampling strobe pulses and therefore achieve small aperture time and therefore good high frequency response. George Frye pondered how to build a very fast (low aperture time) sampler using the components Tek had at the time. He decided to leverage the very short turn-off time of Tek's Schottky diodes. This led to the invention of the traveling wave sampling gate, US patent number 3629731. In this new sampling gate design, the aperture time is not a function of the length of the sampling strobe pulse. Only the falling edge matters. Another way of viewing this is that conventional sampling heads depended on the sampling pulse having a high second derivative, whereas the new design only required a high first derivative. This led to a significantly faster sampling head. The first product using this new sampling gate design was the S-4, which has a rise time of 25 picoseconds.

After Tektronix

George Frye left Tektronix in 1972. In 1973, he incorporated Frye Electronics to produce audiological test equipment [1][2].

Frye Electronics produces instruments for measuring the performance of hearing aids. As of May 2023, George is still actively involved with Frye Electronics.

Selected publications

Documents Authored by George Frye

Document Page Class Title Author(s) Year Refers to
062-1244-00.pdf Book Measurement Concepts: Time-Domain Reflectometry Measurements James A. Strickland H. Allen Zimmerman Gordon Long George Frye 1969 TDR 3S7 3T7
Service Scope 52 Oct 1968.pdf 8 Article A New Approach to Fast Gate Design George Frye 1968 S-4

Products by George Frye

Manufacturer Model Description Designers Introduced
Tektronix 4S2 Dual channel sampling plugin George Frye 1962
Tektronix 4S2A Dual channel sampling plugin George Frye 1965
Tektronix S-4 Sampling Head George Frye 1968
Tektronix 7S11 Sampling plugin George Frye Al Zimmerman Gene Cowan 1969
Tektronix 7T11 Sampling Sweep Unit George Frye Al Zimmerman Gene Cowan 1969
Tektronix 7T11A Sampling Sweep Unit George Frye Al Zimmerman Gene Cowan 1986

Components by George Frye

Model Class Description Designers Used in
155-0001-00 Hybrid integrated circuit gate assembly George Frye S-4
155-0053-00 Hybrid integrated circuit sampler George Frye S-6

Patents by George Frye

Page Office Number Title Inventors Company Filing date Grant date
Patent US 3281705A US 3281705A Wide band signal inverter circuit having separate paths for high and low frequency signal portions George Frye Tektronix Inc 1964-02-03 1966-10-25
Patent US 3297885A US 3297885A Variable width pulse generator employing independently operated switches for controllably discharging transmission line George Frye Tektronix Inc 1964-03-06 1967-01-10
Patent US 3309532A US 3309532A Wave shaping and voltage limiting circuit employing plural snap-off diodes George Frye Tektronix Inc 1964-03-20 1967-03-14
Patent US 3344285A US 3344285A Ramp generator and comparator circuit employing non-saturating gate George Frye Tektronix Inc 1965-01-19 1967-09-26
Patent US 3434049A US 3434049A Time domain reflectometry system having a current source for locating discontinuities in a transmission line George Frye Tektronix Inc 1965-12-06 1969-03-18
Patent US 3524993A US 3524993A Triggering method and apparatus wherein the triggering period is determined George Frye Tektronix Inc 1967-02-17 1970-08-18
Patent US 3629731A US 3629731A Sampling system George Frye Tektronix Inc 1968-07-12 1971-12-21
Patent US 3612915A US 3612915A Triggerable apparatus George Frye Tektronix Inc 1969-05-26 1971-10-12
Patent US 3611003A US 3611003A Oscilloscope signal sampling system George Frye Tektronix Inc 1969-05-26 1971-10-05
Patent US 3612910A US 3612910A Triggered pulse generator having automatic bias adjustment Gene Cowan George Frye Tektronix Inc 1970-07-28 1971-10-12
Patent US 3747002A US 3747002A Time and sequence determining circuit George Frye Tektronix Inc 1971-04-29 1973-07-17
Patent US 3881133A US 3881133A Two dot indicator system George Frye Tektronix Inc 1973-06-18 1975-04-29
Patent US 4069447A US 4069447A Stabilized high-efficiency sampling system George Frye Tektronix Inc 1974-08-19 1978-01-17
Patent US 8995674 US 8995674 Multiple superimposed audio frequency test system and sound chamber with attenuated echo properties George Frye Frye Electronics Inc 2012-05-30 2015-03-31

Links and References