MFJ MFJ-9606, MFJ-9606X User Manual

MFJ-9606 Instruction Manual

6-Meter FM Transceiver

Introduction:

Thank you for purchasing the MFJ-9606 six-meter FM transceiver. This back-to-basics radio is especially designed to cover your favorite simplex, repeater, or packet frequency at low cost. However, low cost doesn't mean low performance! Your MFJ-9606 uses specialized Motorola FM-communication IC's and quality components throughout. You'll enjoy advanced receiver features like a sensitive low-noise front end, dualconversion selectivity, and a selectable-mode squelch. You'll also deliver a solid signal with crystal-clear audio and plenty of power. For even higher-power operation, you can add a Mirage A-1015-G 150-watt or Mirage A-1030-G 300-watt RF-power amplifier without modification. Operating controls are simple--even a beginner can set up and run the MFJ-9606 on voice or packet in a matter of minutes without wading through pages of complex microprocessor programming instructions. At home, or on the road, we think you'll like the way the MFJ-9606 keeps you in touch.

The MFJ-9606 operating frequency is crystal controlled. Unless specified otherwise, your radio comes from the MFJ factory with crystals pre-installed for 52.525-MHz. This is the six-meter national FM calling frequency, and the most widely-used channel for simplex communication. To operate on 52.525 MHz, simply follow the hook-up instructions outlined in the manual. If you wish to change the radio's operating frequency to a repeater or new simplex channel, the manual provides complete easy-to-follow instructions for ordering and installing new crystals.

Typical Specifications:
Receiver:
Frequency Coverage	51-54 MHz
Sensitivity	0.3 uV or less
Selectivity	12.5 KHz
Frequency Control	3rd overtone crystal
1st IF	10.7 MHz
2nd IF	455 KHz
AF Output	200 mW
Squelched current	22 mA
Transmitter:
Frequency coverage	51-54 MHz
Frequency control	Fundamental-mode crystal x 3
Modulation	Variable-reactance NBFM
Deviation	5-KHz
RF output power	10 Watts
VSWR tolerance	3:1 VSWR
Transmit current	2.2 Amps Maximum

MFJ-9606 Instruction Manual

6-Meter FM Transceiver

Set-up Instructions:

Power Supply: The MFJ-9606 may be powered from any well-filtered 13.8-volt DC power source capable of 2.2 amps ICAS. It will also run from any comparable 12-volt source at slightly-reduced RF output. Power supply connection is made through a 5.5mm OD x 2.1mm ID coaxial plug. You may obtain extra plugs at RadioShack as part number 274-1569. Positive [+] voltage is connected to the plug's center pin. Negative [-] voltage is connected to the outer barrel. The MFJ-9606 has a built-in "crowbar" protection circuit to prevent damage from accidentally-reversed power leads. See page 10 for crowbar fuse replacement instructions.

Selecting a Microphone: MFJ-290 and RadioShack 21-1172 CB microphones plug directly into your MFJ-9606 without modification. You may also use any other low-Z (600Ω ) dynamic microphone outfitted with a standard 5-pin DIN connector (RadioShack 274-003) as shown below:

Pin 3 = PTT Line			MIC		4
Pin 4	= Mic Line			PTT
					3
Pin 2	= Ground	3	1
					2
		5	4

			2
		Front Panel View

If you use the MFJ-9606 as a base station, you may take full advantage of the transmitter's exceptional transmitter audio reproduction quality by installing a pro-audio grade dynamic desk microphone or a self-powered electret microphone in place of the hand mic.

Choosing an Antenna: Most six-meter FM stations use vertical polarization. A simple ground plane antenna may be the most economical and practical choice for local-area base-station coverage. For long-range links, a vertically-mounted 3-element yagi can add up to 6 dB of signal strength in the desired direction. On the highway, most six-meter FM mobile operators use a simple 54" trunk or roof-mounted quarter-wave whip. A variety of 6-meter vertical antennas are available from MFJ or through your amateur radio dealer. If you choose to build your own, consult The ARRL Antenna Book or ARRL Antenna Compendium for design and construction details.

For best performance, always mount your antenna high and in the clear--well away from large metal obstructions or dense vegetation. To prevent excessive feedline loss, keep the coax run as short and direct as possible. For cable runs up to 60 feet, RG8X (sometimes called mini-8 or RG8M) provides excellent performance. For longer runs, use a largerdiameter low-loss cable such as RG8 foam-dielectric or Belden 9913. Always adjust your antenna carefully for minimum VSWR. Normally, the VSWR of a properly-designed and installed VHF antenna system should never exceed 1.5:1.

MFJ-9606 Instruction Manual

6-Meter FM Transceiver

MFJ-9606 Controls and Functions:

Front View

SQUELCH VOLUME MIC/TNC

POWER

PWR XMIT

	MFJ-9606 SIX-METER FM TRANSCEIVER			6
2	3	4	5

1.POWER Switch: Turns power on to the transceiver.

2.PWR LED: Indicates when radio is turned on.

3.XMIT LED: Indicates when the radio is transmitting.

4.SQUELCH: Adjusts threshold level for squelch circuit.

5.VOLUME: Adjusts speaker volume level.

6.MIC/TNC: 5-Pin DIN connector accepts microphone plug or TNC patch cable.

Rear View

MFJ Enterprises, Inc	ANT
Starkville, MS USA
AMP POWER
+

1.AMP: RCA jack for keying an external RF power amplifier.

2.POWER: 2.1mm x 5.5mm coaxial power connector for 13.8-Volt source.

3.ANTENNA: SO-238 Jack accepts standard UHF antenna connector.

Setting Controls:

1.Squelch: Eliminates unwanted limiter noise when no stations are being received. With no signal present, turn knob fully counter-clockwise--then slowly rotate clockwise until background noise cuts off . Squelch Mode selection is explained on page 8.

2.Volume: Set the volume control for a comfortable listening level.

MFJ-9606 Instruction Manual

6-Meter FM Transceiver

FM-Deviation Level:

What is Deviation? On FM, the audio waveform from speech or tones is used to vary the transmitter's operating frequency. The amount of frequency variation is called the radio's deviation level. The deviation for a VHF-FM amateur station should never exceed +/- 5 kHz with speech or +/- 3 kHz for packet or DTMF tones. If you underdeviate, your modulation will sound weak and thin in voice mode and your packet mode signals may not "connect". If you over-deviate, your modulation will sound un-naturally loud and distorted--and may even appear to break up or splatter onto adjacent channels. By the same token, your packet signal waveform may clip and fail to decode properly.

Maintaining correct deviation is important--and may become especially critical when communicating through repeater stations. Repeaters using converted commercial twoway FM equipment may be less tolerant of over-deviated signals than less sophisticated amateur equipment. However, this doesn't mean you need expensive test equipment to check your modulation level. Simply ask other stations for on-air audio reports--and follow their suggestions. If your audio is thin and weak, turn deviation level up. If your audio is un-naturally loud and distorted, turn it down. If you sound natural, the deviation control is probably set correctly for your particular voice and microphone.

How to Adjust the Deviation Control:

Remove the radio's top cover and set it aside, taking care not to pull the speaker wires. Find trimpot R24, marked DEV for "deviation". It is located at the center of the pc board, as shown the diagram on Page 7. To decrease deviation level, turn the trimpot adjustment counter-clockwise. To increase deviation, adjust clockwise.

Minimum	Maxmimum
Deviation	Deviation
	R24

If you have a way to measure deviation, set R24 for a 5-kHz indication on peaks while speaking in your normal style--or 3 kHz for packet. If you do not have access to a deviation meter, simply ask another station for an on-air audio check--and adjust the deviation control accordingly. Once a good level is established, avoid yelling or talking more closely than normal. The MFJ-9606 does not have a speech-clipper circuit to prevent over-deviation (one reason for its exceptional audio quality).

IMPORTANT NOTE: If audio reports indicate that your audio is distorted at all deviation control settings, the problem may be that your transmitter frequency is misadjusted and you are transmitting slightly "off-channel". In this case, please refer to the transmitter frequency calibration section of the manual.

+ 9 hidden pages