It has become one of the Groups "sandbox" projects, spearheaded by Chuck, K7QO.
A recent group post by Chuck has planted a new seed for the next sandbox project and it seems to be garnering much discussion:
My idea for the AM BC all transistor radio build is to
celebrate the 60th anniversary of the transistor radio.
Let's not over engineer this and get crazy. BC band only.
4 to 7 transistors. No ICs, since we didn't see ICs in the
early radios and they were a while away from being used.
This is a volunteer project, i.e. you pick and choose
what you want to do. You can use modern components
for your build, but I'm personally going with the simpler times.
By that I mean I'm not going to use an LM386 or other audio
IC and no NE602 mixer, etc.
If you google for 'AM broadcast transistor radio', you will get
link to a large number of schematics. For now, let's all wade
through them and in Sept see if we can find one that might
be a good group project to share and build together. This
for the purpose of learning something and sharing information.
Help the new guys and girls who want to try something different.
I have some 455KHz ceramic filters that I plan on using in place
of the IF transformer. The old radios used a 600 ohm CT audio
transformer to get down to 8 ohms for speakers. I'm going with
ear buds, so may get around the weight of the transformer. Time
So, start doing some research to see what gets your interest in
doing this. I know that we all tune into the AM band, it will not be
like the old days of the old programming. Probably a lot of
religion, conspiracy nuts and other talk shows.....
As a side effect of this project:
Transistor theory books. I found vol 1 and vol 2 of the Sams
series. I put these on < http://www.archive.org > Just go
to the site and search for 'transistor fundamentals' and you
will see Vol 1 by Robert J. Brite and Vol. 2 by Charles A. Pike.
There is a Vol 3 and Vol 4, but I have had no luck in finding them.
Let's hope that some one will put them at archive.org for
preservation. Let us know.
We could, on the side of the AM build, get a study group to
help newbies learn transistor theory and circuits for building
some simple stuff. Wind up with some useful toys and learn
all about transistors in the process. That is if we get enough
Is there a good online course on transistor theory with labs?
There are some newer books on transistors that might be
candidates for a study group.
|Early Transistor Ad - QST March 1953|
The world's first 'pocket transistor' radio was sold in 1954 by Regency.
|1st Pocket Transistor|
To read more about the fascinating history of the 'transistor radio' and the Regency in particular, visit Steve Reyer's Website.
It's wonderful to see such interest in the art of homebrewing and it will surely be fun to see the end results of Chuck's latest seed planting.