Ramsey Electronics FR146, User Manual

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FR146
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INTRODUCTION TO THE FR146 FM RECEIVER
Most Ramsey kits can be classified as “Skill Level 1”. That means that our
kits are intended to be sucessful for first-time kit builders. This FR146 FM
Receiver is best regarded as a “Skill Level 2” project (or at 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 that Two Meters and its maze of
repeaters holds for newcomers, which means this could be your very first kit
project. The same holds true for those who just want to peek in on VHF
public service communications without the cost of a scanner. 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 receiver before assembling the FR146, but we
are confident that you can construct the FR146 successfully if you follow this
manual carefully and patiently.
This receiver is a good project for amateurs wishing to become more familiar
with 2 meter FM before choosing a transceiver, or for those active on 2 who
want an inexpensive receiver to take on trips, keep in a briefcase or to watch
for band openings.
Before beginning the project or even studying the circuit description, it is
worthwhile to develop some prior respect for how much receiver is packed
onto the circuit board. The nine semiconductor devices (diodes, transistors
and IC chips) give the equivalent of about 30 or more transistors diodes.
And, in addition to four inductors, a crystal and two ceramic filters, there are
nearly 60 capacitors and resistors. Surely, all that should result in a decent
receiver! You could easily spend twice the money plus hours of time trying to
gather the equivalent parts from catalogs and still need to make your own
circuit board.
BUILDING YOUR FR146 KIT
There are just over 200 solder connections on the FR146 printed circuit
board. That means your work could be 99% excellent and you could STILL
have 2 or 3 cold solder points or solder bridges. Since this circuit is more
sophisticated than a direct-conversion HF receiver or a simple transmitter, a
beginner or casual amateur could have a harder time tracing a problem due
to a poor solder connection. Therefore, PLEASE take us seriously when we
say that good soldering is essential to the proper operation of your receiver!
ˆ Use a 25-watt soldering pencil with a clean, sharp tip.
ˆ Use only rosin-core solder intended for electronics use.