FR-220
•
22
The small 4 turn coils are stretched or compressed when receiving a
weak signal. Typically the coils are spread to about 1/4 inch width. Make
this adjustment only when receiving a constant weak signal, this simple
"tweak" will significantly perk up your reception!
RECEIVER SENSITIVITY
Your FM receiver features sensitivity under 1 uv. Radio hams constantly
marvel at how an FR220 displayed at hamfests tunes in dozens of
hand-held QSO's on the premises- without an antenna connected! You
can expect to monitor local repeater and simplex transmissions easily,
using a simple groundplane style antenna. The receiver also responds
very well to the addition of a low-noise pre-amplifier such as the Ramsey
SA-7, PR-2 or PR-20. The PR-20, 220 MHz preamp kit features High-Q
tuned circuitry for a significant performance improvement. A new and
versatile receiver accessory is the Ramsey AA-7 HF-VHF Active
Antenna, which doubles as a preamplifier with other antennas in
addition to the excellent performance of its own whip.
ADDING AN LED POWER "ON" INDICATOR
For many people, a pilot lamp to indicate "power on" is more than a nice
touch. They expect it and depend on it, reminding us that "real radios
glow in the dark!" Adding a simple LED power-on indicator to your
Ramsey kit receiver is easy. All you need is the LED itself and a small
1K to 2.2K resistor.
Study the PC traces between the positive battery supply wire and the
on-off switch. The unused connectors on top of your switch are an ideal
point to get the + DC voltage needed for the anode (longer lead) of the
LED. Plan where and how you wish to install the LED in your enclosure.
Locating the LED immediately above the on-off switch is logical and
ideal. The simplest way to make a good installation is to drill a neat hole
just slightly smaller than the diameter of the LED. Then, enlarge the hole
a little bit at a time, just enough to let the LED be pressed in and held
firmly. The resistor may be connected to either the anode or cathode of
the LED, but the anode MUST go to + DC, with the cathode connected
to the nearest common ground point. If you are wondering why we did
not include these pennies worth of parts with your kit, you can believe
any of the following reasons:
Summary of Contents for FR220
Page 8: ...FR 220 8 U2 3359 FR220 BLOCK DIAGRAM U1 SA602 MIXER...
Page 9: ...FR 220 9 FR220 PARTS LAYOUT DIAGRAM...
Page 14: ...FR 220 14...
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