oestex ©®


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transmitting, receiving, industrial, communications, audio, hi-fi, musical and test equipment
DIY, industrial, broadcast and commercial

oestex  ©® is an acronym for "Optimised Electron Stream"© Technology and "Enterprise Excellence"©® - ABN 23 234 404 160

This website is dedicated to the work and memory of Herbert J. Reich PhD., Professor of Electrical Engineering, University of Illinois, who left us his magnificent contribution to explaining electron tube technology through his definitive work - "Theory and Applications of Electron Tubes", McGraw Hill, 1939, 1944

This text has given me more insight and understanding in electron tube behaviour than any other writer.

I commend it to all DIY constructors to guide you in what you are doing and why you are doing it

The information presented in this website is based upon the premise that when subjectively assessing musical tone, sound stage presence and sheer listening pleasure, modern solid state amplifiers unquestionably deliver outstanding test results in the laboratory into resistive loads, however on reactive loads presenting widely varying impedance and power factor in a complex relationship - such as the dynamic loudspeaker - solid state amplifiers continue to remain a poor second to vacuum tube amplifiers.

The humble triode electron tube, with all its faults, still remains the device of choice for the serious audiophile and musician.

If you can accept that claim then these pages will be of benefit to you.



Welcome to the Home Page of:



It's not what you do but the way that you do it !!!!



This website has been set up to assist people needing information for constructing or servicing transmitting, receiving, industrial, military, communications, audio, hi-fi, musical and test equipment applications.

The information presented herein is based upon a combination of the reported experiences of others, helpful guidance from my electronic guru friends, reference to published texts from people who are considered to be reliable technical experts, electron tube manufacturers' manuals, data sheets, catalogues and technical publications, and my own experiments, research and experiences over more than 60 years.

Every concept presented on this site has been proven by practical application or test to work as claimed.

If you wish to add to the body of knowledge in this field I would welcome your thoughts - please email.

This website includes details of:

To connect to a page or link please select and click on the blue text where it appears below

Readers please note this website is set up in a layered hierarchical relationship.

Each DISCRETE SUBJECT page selected from this HOME page offers more links to subsidiary pages and/or other websites.

If you have found a specific page from a search engine then for best navigation please return to the HOME page or DISCRETE SUBJECT page first.


Information about application, use, performance and history of the type 803 RF pentode, developed for WWII military transmitter applications.

This tube was made by a number of manufacturers, including Taylor, RCA, Westinghouse, GE, KenRad and Cetron.

I have adequate technical data and ratings but virtually no history or application circuits.

Any assistance relating to the history of the 803 will be appreciated.

If you can help, please email contact



Tube Design Information for Audio, Broadcast, Modulator and RF Transmitter Service:

Electron Tubes
This page presents an overview of electron tubes and how they work in audio and modulator service

How To
This page presents instructions for designing and constructing a high-fidelity audio system

This page presents information about triode operation of tetrodes, pentodes and beam power vacuum tubes.

This page presents information about requirements for Screen Grids in vacuum tubes; and triode operation of tetrodes, pentodes and beam power tubes.

This page presents information about ultra-linear operation of vacuum tubes.

Optimised Electron Stream ©  Technology
This page presents new applied engineering technologies to improve performance by optimising requirements for the electron stream in tetrodes, pentodes and beam power tubes.

Optimised Ultra-Linear © Operation
This page describes how to optimise conditions for Hi-Fi U/L.

Power Supplies
This page presents instructions for designing and constructing a power supply for a high-fidelity amplifier

Tube Data
This page presents a selection of rare tube data and circuit design information.

Tube Design Theory
This page presents a selection of modern theoretical papers.

This page presents details of audio output transformers.

Tube Testing
This page describes the basic principles for testing Electron Tubes.

Guitar Amplifiers

This page presents a “how-to” for DIY constructors of GUITAR amplifiers.

Bass Guitar Amplifiers

This page presents a "how-to" for DIY constructors of BASS GUITAR amplifiers.

Bass Reflex Enclosure Design

This page presents a proven empirical method for designing bass reflex loudspeaker enclosures

Construction and Wiring of Tube Amplifiers

This page presents some examples of Tube Amplifiers featuring fine quality construction and wiring 

Tubes for Audio Output and Transmitter Modulator Service:

Audio Amplifier and Modulator Applications
This page shows tubes recommended for audio applications

Tube Audio Amplifier and Modulator Circuits:

Audio Amplifier and Modulator Circuits - 50W RMS to 3000W RMS
This page presents some interesting circuit diagrams of selected High Power Amplifiers.
Information is also included for the McIntosh unity coupled amplifier.

The Williamson Amplifier and Derivatives - 15W RMS to 100W RMS
This page presents details of the original and improved Williamson amplifier and a range of later improved versions from others.

These pages are included for your information and education only.

These designs use very high voltages - which can be terminally lethal, require a high level of experience and understanding in amplifier design and construction - particularly component selection, hardware and wiring layout - and are definitely not recommended for the inexperienced or first-time amateur hobbyist to try to construct.

All circuits and information are copyright in their original owner.

The McIntosh Amplifier - 50W RMS to 350W RMS
This page presents some information about the McIntosh range of tube audio amplifiers.

Tube Audio Pre-Amplifier and Control Unit Circuits:

Tube Audio Pre-Amplifier and Control Unit Circuits
This page presents some interesting circuit diagrams of selected High-Fidelity Audio Control Units.


Solid State Amplifiers

The Phonic XP3000 High Fidelity Professional Power Amplifier


Hearing and Hi-Fi Audio:

The HEARING AND HI-FI pages describe what you might hear from hi-fi audio.

These pages show the frequency range of many of the common instruments that we want to reproduce from our audio system.

The Audio Spectrum

Hearing Health

Can you really hear what you think you can hear??

Hearing and Hi-Fi: Daniel H. Cheever

The following articles, courtesy of Electronics Australia, June 1983 edition, may cause you to reconsider what you are actually hearing!!

Hearing and Hi-Fi: Page 1

Hearing and Hi-Fi: Page 2

Hearing and Hi-Fi: Page 3


Extra Special Links:

Extra Special Links
This page shows references to links that I feel are really special for students and users of electron tubes.

Recommended Tube Suppliers:

This page lists suppliers I personally recommend.

Management Related Topics:

Principles of Technology
This page presents a selection of principles that apply to the development and application of technologies.

Principles of Organisation
This page presents a selection of principles that apply to the design and behaviour of organisations and the people who run them - a little tongue in cheek but true.

Quality Consciousness
This page describes a model for developing quality consciousness in organisations

Integrated Management Systems
This page describes a model for integrating management systems in organisations - e.g. quality, safety, environmental, operations, financial, logistics etc


To hear is to forget
To see is to remember
To do is to learn
To learn is to know
To know is to grow
To grow is to give
To give is to live




Knowing is not enough; we must apply.
Willing is not enough; we must do.



"Of all the inventions that have ever made scientific history, the discovery by Lee DeForest that a few turns of wire in between the two elements of a diode vacuum tube were able to control the flow of electrons, can without doubt be classed as among the foremost in its benefits to mankind.

Not only has the three-element vacuum tube been the means of providing entertainment and education to millions of people throughout the world, but it has been proved to be the keystone in the arch upon which has been built innumerable branches of scientific thought."

John F. Rider 1945



Experience is something you don't get until just after you need it!!

Experience comes from bad judgement. Good judgement comes from experience.

Good judgement in audiophilia is to forget about how it "sounds" - just enjoy the music!!!!




"I haven't failed. I've found 10,000 ways that don't work." - Thomas Edison



Never be afraid to try something new.
  Remember that a lone amateur built the Ark.
A large group of professionals built the Titanic



"Creativity requires the courage to let go of certainties."  - Erich Fromm


If it tests good and sounds bad, you might be an engineer or scientist !!

If it tests good and sounds good you might be an audiophile !!

If it tests bad and sounds good, you might be musician !!

If you find yourself constantly striving to make it better - regardless of how well it tests or how well it performs -
then you just might be a DIY inventor !!

The pursuit of excellence is excellent in itself.


A message for all:

"Let the Golden Rule Overrule the Rule of Gold"

By Swami Beyondananda


Note for the uninitiated:

The Golden Rule is: "Do unto others as you would have them do unto you".

The Rule of Gold is: "He who has the gold makes the rule"




Dennis Grimwood

Email:    contact

Location:  Perth,
Western Australia,

Page last updated 10 July 2017

This page URL is http://www.oestex.com/tubes/index.html
806 graphic courtesy "Radiotronics" magazine April 1939