George Frye

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 .

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

• George Frye and Norris S.Nahman, Random Sampling Oscillography. IEEE Transactions on Instrumentation and Measurement, Vol. IM-13 Issue 1, March 1964
• George Frye, A new Approach to Fast Gate Design, 1968 (also in Servicescope No. 52, Oct 1968)
• George Frye, A Predictable Subnanosecond Step Generator. IEEE Transactions on Instrumentation and Measurement, Vol. IM-17 No. 4, December 1968

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	Time domain reflectometers • 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	7T11	Sampling Sweep Unit	George Frye • Al Zimmerman • Gene Cowan	1969
Tektronix	7S11	Sampling plugin	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

• Project Engineer on 4S2A (1966; see Tektronix 4S2A Engineering Spec)
• Designed S-4 Sampling Head (1968)

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