FT146
•
4
INTRODUCTION
Two meter FM has been around for years, but never with the popularity that
is enjoyed today. In the old days, hams snooped around the local two-way
radio shop in search of an obsolete taxi cab or police radio. These radios
were in the 150 - 174 MHz business band and were easily moved down into
the ham two meter band. On the chance that a UHF 450 - 470 MHz radio
was found, it was modified for the ham 440 band. Since there was no
business band near the 220 MHz ham band, no radios were available for
conversion - and that's why the 220 band never became popular!
Well, its been a long step from then to now, and not a pleasant one for ham
radio. We've lost a portion of our 220 band and gave up our ham radio
market to the Japanese. Gone are the radio mavens who could modify, in an
evening, the old Motorolas, GEs and RCAs. Modern day hams don't use
modified commercial radios, they operate rigs designed expressly for
amateur use, and who can blame them? For a half a kilobuck (that's $500 in
regular talk) you can get a full band synthesized 30 watt radio that looks like
a fine piece of audio gear! Good deal but something is missing, and that's the
pride in building, understanding and learning. You see it really doesn't take a
whole lot of smarts to unpack a box that was last sealed somewhere in the
Orient. Building your own rig is one of the most satisfying and rewarding
experiences you can have - and that's what ham radio is all about! This little,
easy to understand two meter FM transmitter is our attempt to provide the
ham community with a simple, fun to build kit that you'll enjoy operating,
especially when you tell the other operator that the rig here is home-brew.
Most Ramsey Electronics can be classified as "Skill Level 1" if we use the old
Heathkit guidelines for ease of assembly. That means that our kits are
intended to be successful for first-time kit builders. This FT146 FM
Transmitter is best regarded as a "Skill Level 2" project, (or least Level 1.46!)
and should not be taken lightly, even by experienced, licensed radio
amateurs.
Still, this step-by-step manual is written with the beginner in mind, because
we are well aware of the fascination Two Meters and its maze of repeaters
holds, which means this could be your very first kit project. To be honest,
we'd like to see first-time builders start out with an easier kit such as the
Ramsey HR-40 forty meter all-mode receiver before assembling the FT146,
but we are confident that you can construct the FT146 successfully if you
follow this manual carefully and patiently.
Before beginning the project or even studying the circuit description, it's
worthwhile to develop some prior respect for how much transmitter is packed
onto the circuit board. The dozen semiconductor devices (diodes, transistors
