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Related Manuals for MFJ MFJ-1775W
Summary of Contents for MFJ MFJ-1775W
- Page 1 WARC Bands Rotatable Mini-Dipole Model MFJ-1775W 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 2006 MFJ ENTERPRISES, INC. VERSION 1D...
- Page 2 A 6'-8' rigid mast or other mounting pipe between 1" and 1.5" outside diameter. (suitable materials include TV mast sections, galvanized iron pipe, or heavy duty rigid conduit.) • Quality low-loss 50-Ohm coax with a PL-259 from antenna to transmitter. An Antenna Analyzer (MFJ-259B or similar), or SWR meter and transceiver...
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Page 3: Specifications
MFJ-1775W 4-Band Rotatable Mini-Dipole Introduction The MFJ-1775W is a mini 14-foot rotatable dipole that is almost invisible from across the street. With its tiny 7-foot turning radius, it fits on the smallest roof and is perfect for town houses, apartments and condos. -
Page 4: Choosing A Location For The Antenna
1-1/2" OD. The use of soft or thin wall masts is not recommended Portable Operation The MFJ-1775W may be disassembled as necessary for transporting to a temporary location. Ideally, just remove the two HF loading coil assemblies leaving the two main elements intact. Some retuning may be required after moving the antenna. -
Page 5: Tools And Time Required For Assembly
MFJ-1775W Rotatable Mini-Dipole Instruction Manual TOOLS AND TIME REQUIRED FOR ASSEMBLY The estimated assembly time is two hours. Antenna assembly requires the following hand tools • #2 Phillips screwdriver • 5/16" nut driver for #6 nuts and hose clamps. •... - Page 6 MFJ-1775W Rotatable Mini-Dipole Instruction Manual Step-By-Step Procedure 1) Set up saw horses or other stable supports (plastic trash cans, chairs, folding tables, etc.) to support the antenna during assembly. 2) Prepare a temporary 6-8’ ground-level mounting mast for easy initial testing and adjustment.
- Page 7 MFJ-1775W Rotatable Mini-Dipole Instruction Manual AL Radiator (2 pcs) Slot Fiberglass Rod ¼-20 hdwr Balun Balun wire (2 plcs) (2 plcs) Figure 3: Radiator Tube Assembly – Top View 7) Slide one hose clamps over each aluminum tube. IMPORTANT: Use a 5/16” nut driver to tighten the capacitance spokes in place. Tighten by hand only.
- Page 8 17) Mount the antenna in the final location. Slight re-tuning may be necessary. FREQUENCY AND SWR ADJUSTMENT An SWR analyzer such as the MFJ-259B or equivalent is highly recommended when tuning the MFJ- 1775W. While a transceiver and SWR meter can be used, an SWR analyzer will significantly decrease the time and effort necessary to tune the antenna.
- Page 9 MFJ-1775W Rotatable Mini-Dipole Instruction Manual The entire antenna must be accessible during initial coarse tuning and testing. Any repair or adjustment to the antenna after it is installed on a tall support will make adjustments difficult and time consuming. It is best to install the antenna on a short temporary mast or pipe that is located in a reasonably clear location for tuning.
- Page 10 MFJ-1775W Rotatable Mini-Dipole Instruction Manual CAUTION: Use a pair of pliers to hold the outer piece of each spoke that is to be cut off so as to keep the cut piece from flying off and causing injury. The following tips will help you obtain a better SWR on 60 meters than the tuning method used on other bands.
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Page 11: Grounding Considerations
MFJ-1775W Rotatable Mini-Dipole Instruction Manual 6) When all tuning is complete, install the plastic end caps on the outer ends of all spokes. Note that the plastic end caps will lower the resonant frequency on all HF bands by 30-50 kHz. The plastic end caps should fit snugly on the spokes. -
Page 12: Maintenance
MFJ Technical Service at 662-323-0549 or the MFJ Factory at 662-323-5869. You will be best helped if you have your unit, manual and all information on your station handy so you can answer any questions the technicians may ask. - Page 13 MFJ-1775W Rotatable Mini-Dipole Instruction Manual...
- Page 14 MFJ-1775W Rotatable Mini-Dipole Instruction Manual NOTES:...
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Page 15: Full 12-Month Warranty
MFJ Enterprises, Inc. warrants to the original owner of this product, if manufactured by MFJ Enterprises, Inc. and purchased from an authorized dealer or directly from MFJ Enterprises, Inc. to be free from defects in material and workmanship for a period of 12 months from date of purchase provided the following terms of this warranty are satisfied. - Page 16 MFJ ENTERPRISES, INC. MFJ-1775W Manual 300 Industrial Park Road Version 1D Starkville, MS 39759 Printed In U.S.A.