RAT5 Manual version 1.2.0
RAT5 Information Manual version 1.2.0 © GW4GTE 2010
Page 4 of 29
1. Introduction
What is it?
The RAT5 is a single conversion AM receiver for 80m and 160m (operation on other
frequencies is also possible).
The receiver is based on the TDA1072A AM receiver IC which although obsolete is still
available in quantity from at least one source and a reasonable number has already been
obtained for kit builders.
The low cost and ease of construction make this an ideal club project, and to this end
component values are also provided to cover the Medium Wave where signals to tune into
are plentiful. No previous experience of kit-building is required, just basic soldering skills.
What does RAT5/FAT5 mean?
For some years now the author has been playing about with home brew solid state AM
transmitters, largely based on solid-state Class-E designs using low cost FETs. This is the so-
called FAT5 series.
The FAT5 name came from the original idea of making a solid state version of the AT5, using
FETs. So, FET-AT5 became truncated to FAT5. RAT5 is an AM receiver to go with the FAT5
transmitter project. Maybe the complete RX/TX could be the FAT-RAT project?
Is there a kit?
Yes. Based around a 3”x2” drilled and tinned single-sided fibre-glass PCB the kit contains all
the components for the project. All that is required in addition is an antenna, power source,
loudspeaker, control knobs and case. For ordering details check
www.s9plus.com
or email
the culprits below.
It’s a big manual for a little kit?
This is the complete reference document containing everything about RAT5. To just build the
kit most of the sections can be ignored. Please read the entire document before starting
construction.
Project Support
This is a supported project, with free advice offered before, during and after construction.
Who to Blame
Circuit design and PCB layout by Dave GW4GTE.
PCB production and kit distribution by Eric GW8LJJ.
Contact Points
Dave GW4GTE: gw4gte @s9plus.com; address is QTHR or see QRZ.com
Eric GW8LJJ: [email protected] ; address is QTHR or see QRZ.com
Acknowledgements
The author extends grateful thanks to ‘Ferric’ Eric GW8LJJ for the production of such
excellent PCBs at ham-friendly prices. It is no exaggeration to say this and several other
designs would never have seen the light of day as completed projects without Eric’s
enthusiasm and support.