Related Manuals for MFJ hamProAudio MFJ-654
Summary of Contents for MFJ hamProAudio MFJ-654
- Page 1 Model MFJ-654 INSTRUCTION MANUAL CAUTION: Read All Instructions Before Operating Equipment MFJ ENTERPRISES, INC. 300 Industrial Park Road Starkville, MS 39759 USA Tel: 662-323-5869 Fax: 662-323-6551 COPYRIGHT MMVI MFJ ENTERP RISES, INC. VERSION 1A...
- Page 2 Customers using this manual should report errors omissions, recommendations for improvements, or other comments to MFJ Enterprises, 300 Industrial Park Road, Starkville, MS 39759. Phone: (662) 323-5869; FAX: (662) 323-6551. Business hours: M-F 8-4:30 CST.
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Page 3: Table Of Contents
INTERNAL HEADERS b. INTERNAL JUMPER BLOCK c. CABLES d. POWER e. HEADPHONES RADIO AUDIO 7. THEORY OF OPERATION 8. MFJ-654 EASY-START INSTRUCTIONS 9. IN CASE OF DIFFICULTY 10.TECHNICAL ASSISTANCE LIST OF FIGURES Figure 1 Front Panel Jacks and Controls Figure 2... - Page 4 2. Standard 8 pin round chassis connector for the majority of the radios produced in the last 25 years. 3. MFJ’s own input consisting of a 3.5 -mm jack that allows the user to choose from feeding audio, audio and a PTT function for use with the Heil...
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Page 5: Introduction And Features
Audio Pass Through from your Radio: No need to switch the headphones from the MFJ-654 to the radio. At the push of a button you can instantly switch from normal operation to a test mode that allows you to adjust the settings without going on the air with the built in monitor amplifier. -
Page 6: System Controls
OUTPUT LEVEL POWER MFJ-654 10 11 12 13 Figure 1: MFJ-654 Front Panel Jacks and Controls Bottom Rows 1. 8 pin Microphone Input Jack: Accepts input from any standard 8 pin microphone. 2. RJ-45 Microphone Input Jack: Accepts the input from a standard RJ-45 Microphone. - Page 7 Great to hold the audio open between syllables and words. 10. Power On LED: Instant visual identification if you are using the MFJ-654 or just the standard microphone. 11. Monitor Gain: Control the audio level in the headphones when in the test position.
- Page 8 1. Power: Accepts 2.1 –mm power plug to supply 12-15 Vdc to the unit. 2. From Radio/From MFJ-654: This switch allows the audio to be fed from the radio to the headphones or in the test mode for the audio from the microphone to be fed to the headphones for setting the MFJ-654.
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Page 9: System Setup
J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual SYSTEM SETUP INTERNAL HEADERS Figure 3: Internal Headers 1. Header 1: This sets the input of the unit to your specific microphone. Default 1-2 is set to 680 ohms the standard impedance setting for most stock microphones. If you need low impedance then move the jumper to positions 3-4. -
Page 10: Figure 4-10 Internal Jumper Blocks
J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual SYSTEM SETUP Figure 4: Internal Jumper Blocks Refer to Table 1 for common microphones. Consult your owner’s manual to determine your specific microphone pinout. 1. Jumper 2: PTT from the Microphone. Place a jumper on the pin number that corresponds to the pin of your microphone that supplies the PTT line to the radio. -
Page 11: Internal Jumper Block
The Jumper Installation diagrams within this instruction manual will help you in setting up your MFJ-654 to match your radio. If your radio is not listed with the diagram, it means that we have not verified your radio to use that diagram. You can try to install jumpers as indicated. - Page 12 If there are any Questions concerning the information provided, please refer to your RADIO INSTRUCTION MANUAL. MFJ is neither liable nor responsible for any mistakes or errors in the information provided. Receive Audio is taken from the Headphone Audio Output.
- Page 13 If there are any Questions concerning the information provided, please refer to your RADIO INSTRUCTION MANUAL. MFJ is neither liable nor responsible for any mistakes or errors in the information provided. Receive Audio is taken from the Headphone Audio Output.
- Page 14 If there are any Questions concerning the information provided, please refer to your RADIO INSTRUCTION MANUAL. MFJ is neither liable nor responsible for any mistakes or errors in the information provided. Receive Audio is taken from the Headphone Audio Output .
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Page 15: Figure 12 Yaesu Mic Jack Pinout, Front View
J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual SYSTEM SETUP CUSTOMIZING INTERNAL JUMPERS If your radio is not listed above, you can create a custom jumper position table. Begin by removing the screws from the sides of the cabinet. Lift the cover off. Look from the front view and notice the group of pins and black jumpers on the left side behind the microphone connector and in front of the microphone output jack. - Page 16 J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual SYSTEM SETUP 1.) Jumper 4 and 9 should copy each other, and use the same jumper pin number for the center MIC wire. 2.) Jumper 2 and 7 also jointly share the same pin numbers as the PTT pin.
- Page 17 J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual SYSTEM SETUP Radio Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8 Alinco DOWN AUDIO VOLTS Icom UP/DOWN AUDIO VOLTS DOWN Kenwood AUDIO VOLTS Yaesu FT1000 DOWN FAST FT847...
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Page 18: Cables
CABLES Simply connect your microphone to the appropriate input and use either a MFJ- 5398 for 8 pin Round or MFJ-5397MX for 8 pin Modular connector to the output on the rear of the unit and attach to your radio. -
Page 19: Theory Of Operation
The average time for this feature is set by the Delay control on the front panel. Overall gain of the MFJ-654 is set by controlling the Vca through the front panel control. Gains of up to 20 dB are available. Compression is set by the front panel control and ratios of 1:1 up to 15:1 are possible. -
Page 20: Figure 14 Compression And Gating Characteristics
J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual THEORY OF OPERATION Figure 14: Compression and Gating Characteristics Figure 14 shows how the input levels are compressed for various levels of compression within the SSM2166. Compression is a method of signal processing that the loudest signals are made softer and the quietest signal are boosted this reduces the overall dynamics of the signal but this also makes the output appear louder to the ear. - Page 21 Instruction & Technical Manual EASY-START INSTRUCTIONS 1. Start with the MFJ-654 Bypass switch in the ON position. Using your microphone, set your radio’s mic gain, ALC and any other features to the proper operating condition. Set the front panel controls as follows: Compression: 9 o’clock...
- Page 22 12. Place the unit in the From Radio Position and set your audio until it is at a comfortable level in the headphone. You are now more familiar the MFJ-654, and you are almost ready to get on the air. It will take some to get familiar with the amount of Compression you need, as it is always a trade off between fidelity and the use of Compression to get that rare DX station you have been after.
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Page 23: Technical Assistance
Don’t forget to use the bypass switch often to make comparisons. You are now set to use the MFJ-654 on the air. It will take some to get familiar with the amount of Compression that you need as it is always a trade off between fidelity and the use of Compression to get that rare DX station you have been after. -
Page 24: In Case Of Difficulty
Ensure the Test/Operate switch on the rear of the unit is in the Operate position. [ ] Station PTT will not function: Check the PTT jumper block. Ensure that you have a ground between the radio and the MFJ-654 as the Mic Ground is isolated from the Chassis Ground. -
Page 25: Figure 15-16 Schematic
J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual Schematic (Equalizer) -24-... - Page 26 J-654 hamProAudio Microphone Equalizer/Conditioner Instruction & Technical Manual -25-...
- Page 27 MFJ Enterprises, Inc. agrees to repair or replace at MFJ's option without charge to the original owner any defective product provided the product is returned postage prepaid to MFJ Enterprises, Inc. with a personal check, cashiers check, or money order for $10.00 covering postage and handling.
- Page 28 MFJ-654 Manual 300 Industrial Park Road Version 1A Starkville, MS 39759 Printed In U.S.A.
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