Alfred P. Morgan One Stage Audio Amplifier

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Alfred P. Morgan Amplifier
Alfred P. Morgan Amplifier
This is the one stage crystal radio amplifier from page 100 of "The Boys Second Book of Radio and Electronics" by Alfred P. Morgan, written in 1957. You can find a copy here.

This is probably the simplest project in any of the Morgan books. It only has two parts and a battery! At least, it used to be simple, but being as it was 60 years after the book was printed, I ran into a bit of difficulty with the parts.

The parts list is what made things difficult. See anything unfamiliar?

We need two Burgess No. 7 dry cells. What the heck is a No. 7 dry cell??

Apparently, Burgess manufactured an AAA size dry cell and named it the Burgess Number 7! Notice Morgan calls the battery holder a "transistor battery" holder, so the Number 7 battery was designed for transistor applications. With a printer, some battery labels found online, two AAA cells and a glue stick, we have some Burgess Number 7 dry cells.
An old Radio Shack catalog confirms the No. 7 is size AAA


Here is the layout showing how to mount the dry cells if you don't have a battery holder. I made one according to the instructions, but it didn't look right because it was too wide.
Well, it didn't look right because the bracket in the drawing isn't an inch wide as it states in the instructions. It's the width of two Fahnestock clips. Look at the dimensions; 1 inch by 2 and 7/16 inches long. C'mon, man. Can't it be two and a half inches long? Do I really need to measure one and seven sixteenths of an inch?

It's actually one half inch by 2 inches. I had trouble bending the metal in the big clunky vise in the basement, so I ended up with several. They were made from a scrap piece of roof flashing.

What about the base? It's 4 in. x 3 in. x 3/4 in. If you went to a lumber yard and asked for this you'd have a base that is 3.5 x 2.5 x .5 inches. Let's just take it at face value and make it exactly as Morgan said.


We also need three "No. 10 Fahnestock Spring Contact Clips." Did you know they came in sizes? Me neither. What is a Number 10 Fahnestock clip? This is right up there with the Number 7 dry cell. After asking and searching far and wide, guess who had some. Mike Peebles! He had 21 of them and GAVE them to me.

By far, the most difficult item to acquire was the Raytheon CK722 transistor. They haven't been made in over half a century. There are still some out there; some are the most prized possessions of their owners. I've never seen one in person.
Alfred P. Morgan Amplifier
You may well ask, "How did you build the amplifier if you've never seen a CK722 transistor?"