MFJ MFJ-9417 Instruction Manual

Model MFJ-9417

INSTRUCTION MANUAL

VERSION 1A

CAUTION: Read All Instructions Before Operating Equipment

MFJ ENTERPRISES, INC.

300 Industrial Park Road

Starkville, MS 39759 USA

Tel: [phone] Fax: [phone]

CO PY RIGH T 20 12 MFJ ENT ER PR IS ES, INC .

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MFJ-9417 Installation Manual 17-Meter SSB Travel Radio

INTRODUCTION

Congratulations on your choice of the MFJ-9417 17-Meter transceiver. The MFJ-9417 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. Lets begin with
an introduction to some special features we think you’ll like!

FEATURES

EASY TO OPERATE: The MFJ-9417 is an easy-to-operate,” back to basics" radio. Operate the
unit with ease in minutes!

GREAT SENSITIVITY: A quiet double-balanced mixer front end and lots of overall gain for
great sensitivity. If the signal is there, you will hear it!

ANALOG S-METER: Adjust your 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. Fine Tune lets you zero-in
smoothly.

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 2SC3133 PA runs cool, tolerates 3:1 VSWR, and
won't fail from an accidentally opened or shorted feedline.

MADE TO LAST: Conservative design, with a premium plate through pc board, quality
components, handsome brushed panel, and a tough vinyl-clad case ensure years of dependable
service.

At home or on the go, you will enjoy countless hours operating the MFJ-94217. 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!

MFJ-9417 Installation Manual 17-Meter SSB Travel Radio

QUICK START INSTRUCTIONS:

You will need three things to get your MFJ-9417 on the air fast:

[ ] 12-14 Volt 2-Amp Power Source
[ ] 600 Ohm Dynamic PTT Microphone
[ ] 17-Meter Antenna

1. POWER SUPPLY: The MFJ-4114 AC/NiCd Portable Power Pack or MFJ-4110 AC wall­adapter supply are Especially designed to run the MFJ-9417. However, you may 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
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.

2. MICROPHONE: The MFJ-9417 speech processor circuit was designed around the

companion MFJ-290 600 Ohm Dynamic Microphone. Radio Shack's 21 1172 replacement
microphone also plugs in without modification and works well. If the mic you select requires a
plug, install a 5 Pin DIN connector (Radio Shack 274 003) as shown:

Pin 3: PTT Line
Pin 4: Mic Line
Pin 1,2,5: Ground

3. ANTENNA: We recommend using your MFJ-9417 with any efficient 17-Meter antenna
exhibiting a VSWR of 2:1 or less. AVOID USING ANTENNAS WITH UNKNOWN OR HIGH
VSWR. The MFJ-9417 PA is rugged, but not protected by high VSWR shutdown circuitry and
you may generate out-of-band parasitics if a high VSWR load (3:1 or greater) is present.

IMPORTANT OPERATING NOTES

Your MFJ-9417 features a very potent speech processor. PLEASE RESIST THE
TEMPTATION TO SHOUT OR "CLOSE TALK" INTO THE MICROPHONE IN ORDER TO
BE HEARD! Instead, hold the mic about 2" away and speak normally. The S-Meter should
deflect about 1/2 scale as you speak -- although this may vary somewhat with antenna load.
When operating in noisy environments, you may find it necessary to turn down the mic gain
control (a screwdriver adjustment located on back panel) to reduce background noise.

The MFJ-9417 uses an analog VFO tuning dial that is inherently less accurate than digital
readouts (on the plus side, the analog VFO reduces phase noise, lowers power consumption, and
saves you money). As the licensed operator, you are responsible for staying inside your
authorized band allocation. Please take the potential for dial error into account when operating
near the band edge.

MFJ-9417 Installation Manual 17-Meter SSB Travel Radio

A

V

TYPICAL SPECIFICATIONS

RECEIVER SECTION:

Frequency Coverage: 18.068 to 18.168 MHz
Receiver Type: Single conversion superhet
VFO Frequency: 5.8 MHz Range
IF Frequency: 12.288 MHz
IF Selectivity: -6 dB at 2.5 KHz
AGC: Audio-derived
Sensitivity: < 0.5 uV for 12 dB S/N
Audio: > 1 Watt into 8 Ohms at 10% THD
Receive Current: 50-100 mA typical

TRANSMITTER SECTION:

RF Power Output: 12W PEP (8-10W CW)*
VSWR Tolerance: 3:1 VSWR
Maximum Current: 2.0 Amps peak at 13.8 VDC
Audio Enhancement: RF compression processor

* Requires CW adapter module

BLOCK DIAGRAM:

VFO

RX BPF

L1-L2

SW-Q6

RX MXR

U1

FILTER

BUF

Q1

XTAL

IF AMP

U2

BFO /

PROD DET

U3

M

F S

PTT

SW-Q5

AF AMP

GC

Q2-Q4

U4a

SW-Q7

AF PWR

U5

OL

T / R

K1

MIC AMP

U4b

BAL MOD

U6

SW-Q8

TX MXRU7TX BPF

L5-L6

PRE-DRVQ9DRV

Q10PAQ11

LPF

MFJ-9417 Installation Manual 17-Meter SSB Travel Radio

THEORY OF OPERATION

RECEIVER:

Four-pole bandpass filter L1-L2 preselects incoming 17-Meter signals. Active mixer U1
amplifies and converts them to 12.288 MHz using a self generated 5.8 MHz VFO signal. Crystal
ladder filter Y1-Y6 sets the message-channel bandwidth (diode switching routes transmit and
receive signals through the filter and U2). IF-amplifier U2 provides AGC controlled IF gain in
RX and RF compression speech processing in transmit.

The DC amplifier Q3/Q4 drives the AGC input of U2 and the S-meter circuit. In RX, AGC is
audio derived from AF pre-amp U4a (switch Q2 sets slow AGC decay for SSB reception). On
transmit, processor control voltage is derived from PA level detector D9 (Q2 sets fast decay for
syllabic processor).

Receiver product detector U3 demodulates incoming SSB signals (12.288-MHz LO is self
generated by U3). U3's audio output feeds U4a, a preamp and active LP audio filter. U4a drives
ACG detector D6/D7 (input to U4a is killed by switch Q5 during TX to disable the AGC path to
U2). U4a also drives AF power amplifier U5 through the volume control. U5, which powers the
speaker during RX, is gated into standby during TX to prevent residual feed through.

TRANSMITTER:

Microphone speech amp U4b drives balance modulator U6 during TX (switch Q6 kills U4
output to prevent mic bleed through via U6/U2 during RX). LO for U6 is derived from U3's
BFO oscillator. Q8 is used to unbalance U6 for carrier or CW generation. DSB output from U6
is routed to Y1 Y6 via switch D1/D2 for removal of LSB products and carrier artifacts. After
undergoing dynamic compression in U2, the processed USB signal is routed to transmitter mixer
U7 by switch D3/D4 where it is mixed with 5.8-MHz VFO (VFO signal is sampled from U1's
oscillator and buffered by Q1). Bandpass filter L5-L6 selects the 18.1 MHz mixer product and
feeds it to pre-driver Q9. Q9 feeds driver Q10. Q10 drives PA stage Q11. Q11 operates in
single-ended class AB with bias generated by clamping diode D10. T5 matches PA output to a
50 Ohm system, and low pass filter L7-L8 suppresses harmonic content. Level detector D9
tracks the SSB speech envelope and generates feedback to Q3/Q4 and U2. Syllabic compression
of the speech waveform optimizes average transmitter output power. The MFJ-9417 is
especially designed to operate from lightweight constant current power sources such as NiCd
cells or the MFJ wall-adapter AC supply.

SWITCHING AND REGULATION:

Q7 activates relay K1, which routes the antenna line and activates the +T and +R buses (+T and
+R buses power some stages, key switch nodes, and bias Q11 on during TX). Adjustable
regulator U8 sets Vcc for low-level stages. Fixed regulator U9 sets U1 operating voltage to
ensure VFO stability. Crowbar diode D11 and a pc track fuse protect the radio from reverse
polarity.