MFJ-9420 Installation Manual
20-Meter SSB Travel Radio
INTRODUCTION
Congratulations on your choice of the MFJ-9420 20-Meter transceiver. The MFJ-9420 is specially designed to
deliver performance you never thought possible from a low power radio. Please read this manual carefully before
attempting to operate your new radio.
FEATURES
EASY TO OPERATE: The MFJ-9420 is an easy-to-operate,” back to basics" radio. Operate the unit with ease in
minutes!
GREAT SENSITIVITY: Quiet DBM front end and lots of overall gain for great sensitivity. If the signal is there,
you will hear it!
ANALOG S-METER: Adjust the tuner or aim the beam with pinpoint accuracy. A calibrated analog S-Meter
measures even the smallest variations in signal strength. The meter also monitors your speech processing level on
transmit.
EXCELLENT SELECTIVITY: Sharp ladder filter cuts adjacent chatter and focuses transmitter power where you
need it most for great selectivity.
SMOOTH, STABLE VFO: Effortless tuning with custom manufactured 8:1 reduction drive ball bearing VFO
tuning capacitor provides smooth and stable VFO.
POWERFUL AF OUTPUT: Big audio and powerful AF output even in noisy locations from a special Philips BTL
audio chip and rugged 3" speaker.
FULL-TIME RF SPEECH PROCESSING:
Commanding speech cuts through QRM and competes with radios
running far more power. Compare with your 100-watt rig. You will be amazed by the signal reports!
TRAVEL LIGHT: Packs the same punch as 50-Watt radios without the heavy 10 Amp power supply! Designed to
run on NiCd's or the ultra light MFJ-4110 AC wall adapter supply.
RUGGED TRANSMITTER: Bullet-proof Motorola PA transmitter runs cool, and tolerates 3:1 VSWR accidentally
opened feedlines or feedline shorts.
MADE TO LAST: Conservative design, with a premium plate through pc board, quality components, handsome
brushed aluminum panel, and a tough vinyl clad case ensure years of dependable service.
CW ADAPTER AVAILABLE: Install the MFJ CW adapter board jump to the low end to work CW. Semi-break in
keying and sidetone.
At home or on the go, you will enjoy countless hours operating the MFJ-9420. Best of all, it is fully backed by
MFJ's exclusive "No Matter What" 1 year guarantee. If it breaks, we will take care of it!
QUICK START INSTRUCTIONS:
You will need three things to get your MFJ-9420 on the air fast:
[ ] 12 14 Volt 2 Amp Power Source
[ ] 600 Ohm Dynamic PTT Microphone
[ ] 20-Meter Antenna
1. POWER SUPPLY: The MFJ-4114 AC/NiCd Portable Power Pack or MFJ-4110 AC wall-adapter supply are
Especially designed to run the MFJ-9420. You may also use any 13.8 Volt supply or 10-cell NiCd pack as long as it
delivers 2 A on peaks (12 Volt supplies will work fine but at reduced RF output). Use a 5.5mm OD x 2.1mm coaxial
type power plug (Radio Shack 274-1567) with (+) connected to the center pin.
