On Apr 16, 7:12*pm, Kenneth Scharf wrote:
Ever since I got my ham ticket (in 1970) I've always wanted to build a
complete transceiver. *(I DID build a Heathkit SB102). *The project
always seemed a bit too complex though. *The problem was I couldn't
build it a piece at a time, and be able to then put all the bits in a
box. *In order to do that I'd have to design the entire rig ahead of
time so all the subsystems could have access to the panel for their
controls.

Fast forward. *Today what with micro-controllers and control by wire
parts (such as varicap diodes, digital pots, dds chips, etc) all the
subsystems can go anywhere and you only have to have room in the box for
all of them.

I've started designing a home brew transceiver around a few modules I've
seen on line and in various magazines. *I've got a DDS-60 for my VFO and
I'm programming an Atmel atmega32 processor to control it. *A Bandpass
filter design by PA3AKE using toroids, an IF amplifier by W7ZOI and
WA7MLH using fets and bipolar transistors, and a product detector (from
a direct conversion receiver) by KK7B will form the basis for the
receiver. *I have some 9 mhz if filters purchased at Dayton many years
ago. *The transmitter stages will be based on 'stock' HB circuits.
Later I might add KK7P's DSP unit with the PicaStar software.

So far I have the DDS working and I've built the KK7B product detector
and audio filter board. *I still have to build his audio amplifier
circuit (I divided the project into two circuit boards). *I started
working on a cabinet to house the completed rig in. *I had a nice
surplus cabinet purchased in NYC back in the 1970's in my junk box just
waiting for a project. *Over the past two weeks I've been cutting
openings in the front panel for the controls, LCD, and keypad. *I still
have to repaint the panel and the cabinet (40 years of storage hasn't
helped the finish!).

Homebrew is still alive! It's interesting to ponder how you're
adapting to modules that are available, and apparently avoiding having
to directly deal with nasties like ICs with thermal pads on the back
and ball grid arrays -- and comparing that with the parts that were
available back when you got started in ham radio. It's also
interesting how you are picking "modules" out of the published works
of other hams, to get to a design you can call your own while giving
credit to those original authors too. Thanks for sharing, Kenneth!

Cheers,
Tom