H. P. Friedrichs (AC7ZL) Homepage





My Books 


My Books

I've written, illustrated, and published several books. I have tentative plans for creating more. These links will tell you everything you might want to know about them.

 The Voice Of The Crystal

How To Build Working Radio Receiver Components Entirely From Scratch

In early 2000, I published my first book, entitled The Voice Of The Crystal, (or VOTC for short.) VOTC is a hands-on guide to building radio equipment from scratch. By "scratch," I don't mean store-bought components. Rather, this book describes the basic theory and construction of equipment from virtual garbage, i.e., hanks of wire, bits of metal, a magnet, a chunk of fool's gold, a shoe polish tin, a cigarette lighter, etc.

The construction process is a lot of fun, and the end results are quite beautiful. This link will take you to the official web page of the VOTC, where you'll find descriptive text, photos, critical reviews, and ordering information.

 Instruments Of Amplification

Fun With Homemade Tubes, Transistors, And More

The Voice Of The Crystal was so well received that I immediately considered writing another book. Several of my readers suggested that I put together a book of vacuum tube or transistor circuits to serve as a companion volume to VOTC. I balked at the idea, because instructions for building these types of circuits are available everywhere.

On the other hand, I had never seen a book describing how to build the amplifying components themselves, i.e., tubes, transistors, and the like. In the spirit of "extreme" homebrew and the "from scratch" engineering championed in the last book, I decided that a volume on this topic would take my readers to the ultimate next step.

Marvelous Magnetic Machines

Building Electric Motor Models From Scrap

Electric motors are magic. Electricity goes in, and they spring to life. They actually do something! Lot's of people have built crude electric motor models in their garage and basement workshops, but few attempt to build fine machines, assuming that the tools and materials needed are out of the reach of the casual experimenter. Not so, as I demonstrate in Marvelous Magnetic Machines (or MMM for short).

Follow this link for more information.

I Want A Copy! Where Can I Buy These Books?

I do not sell books myself, and my books cannot be ordered through this web site. However, they are available through a growing list of outstanding sellers and distributors. Follow this link to find out who they are

What If I Want A Whole Carton Of Books? What do I do?

As I indicated above, I do not sell books myself. Instead, I rely on a small group of excellent book sellers, distributors, societies, and retailers. Needless to say, I am always interested in expanding my distribution. If you are a book seller or dealer, let's talk. BTW, I'd love to expand into the U.K. and Australia!

I am also interested in promoting science, engineering, and experimentation among the young. If you represent a school, scout group, or similar organization, please drop me a line

I'd Like To Review Your Book For <fill-in-the-blank>

Great! Complimentary copies of any of my books are available simply for the asking. Please send me an email identifying yourself, who you write for, and the nature of your employer's business.


(revised 04/26/20)