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MFJ-1789 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. 

 

Small (4”-6”) adjustable wrench OR 

o

 

3/8" wrench for 6 and 2 meter stub nuts 

o

 

Two  7/16"  open-end  wrenches  (or  wrench  and  nut  driver)  for  U-bolts  and 
center insulator bolts. 

 

Heavy wire cutters for trimming capacitance spokes 

 

Pliers for holding the spoke ends as they are trimmed 

 

Safety glasses. 

 
You also need two stable supports at least 30" tall (saw horses, trash cans, etc) during assembly, and a 
short (6-8') temporary mast (1 to 1-1/2" OD) for temporary mounting during tuning. 

 
 

SAFETY PRECAUTIONS: 

 

WARNING!  You  can  be  killed  if  the  antenna,  feedline,  or  the  equipment  used  to  install  the 
antenna accidentally contacts any utility lines.  Never install an antenna near power lines! 

 

1.

    Be  careful  while  climbing  and  carrying  the  antenna.    It  is  heavy  enough  to  cause  you  to  lose  your 

balance if it is handled too casually or if the capacitance spokes are snagged on a gutter, ladder, tree 
limbs, etc. 

 

2.

    Mount  the  antenna  high  enough  so  that  it  is  out  of  reach.    The  ends  of  the  capacitance spokes can 

cause eye injury, serious RF burns or both. 

 

3.

    Make  sure  that  the  mast  is  sturdy  enough  to  support  the  15  pound  weight  and  the  wind  loading  of 

approximately 2 square feet.

 

 
 

ASSEMBLY and INSTALLATION PROCEDURE 

 

Refer  to  the  figures  in  this  manual  during  assembly.    Assembly  consists  of  putting  together  the 
balun/center  insulator  assembly,  then  connecting  the  aluminum  radiating  elements  to  the  balun/center 
insulator  assembly.    Next  the  6-  and  2-meter  stub  elements  are  installed.    Finally  the  loading  coil 
assemblies are assembled and installed on the aluminum radiating elements. 
 

Содержание 1789

Страница 1: ......

Страница 2: ...ket 4 805 1796 7 Fiberglass Stabilizer Insulator 4 807 1796 6 Aluminum Stub Channel Bracket 4 808 1796 5 1 x 12 Fiberglass Rod 1 808 1775 12 1 1 8 x 60 AL Tube 2 810 1796 2 1 8 AL ROD 27 IN 2 EXTRA 10...

Страница 3: ...st versatile rotatable dipole Each HF band uses separate efficient end loading coils wound on fiberglass forms with TeflonTM wire and capacitance hats no lossy traps 6 and 2 meters are full length hal...

Страница 4: ...ightning protection WARNING Always mount this antenna so that it is out of the reach of adults and children The capacitance elements can cause injury and or severe RF burns Permanent Installation The...

Страница 5: ...ent used to install the antenna accidentally contacts any utility lines Never install an antenna near power lines 1 Be careful while climbing and carrying the antenna It is heavy enough to cause you t...

Страница 6: ...4 After examining the antenna parts gather the following tools needed for assembly 2 Phillips screwdriver 5 16 nut driver for 6 nuts and hose clamps Small 4 6 adjustable wrench OR o 3 8 wrench for 6 a...

Страница 7: ...tube fiberglass assembly and through the balun lugs Add the 20 split lock washers and nuts and tighten securely See Figure 3 8 Slide four hose clamps over each aluminum tube Slide two hose clamps one...

Страница 8: ...rings of both loading coil assemblies loosely holding them in place with their associated nuts Position the screws so the threaded ends of the screws are pointed outward towards the two ends of each l...

Страница 9: ...clamp onto the aluminum radiator Slide the aluminum radiator tube until it contacts the mounting screw that was just loosened Slide the hose clamp over the tab and tighten the hose clamp to firmly at...

Страница 10: ...e the resonant frequency Conversely adding a longer capacitance spoke will lower the resonant frequency of a loading assembly Spare spokes are included in case you need to lower the resonant frequency...

Страница 11: ...l sections from the end of the spoke until the antenna resonates approximately 15 KHz below the desired operating frequency Use the chart below to approximate the amount of spoke to be trimmed Trimmin...

Страница 12: ...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 Should a cap fit too...

Страница 13: ...r the barrel of the coax connector The sealer should ONLY be placed near the junction of the threaded part of the chassis connector and the knurled area of the male connector This will leave the botto...

Страница 14: ...MFJ 1789 Rotatable Mini Dipole Instruction Manual 14 NOTES...

Страница 15: ...cover postage and handling 4 This warranty is NOT void for owners who attempt to repair defective units Technical consultation is available by calling 662 323 5869 5 This warranty does not apply to k...

Страница 16: ...MFJ 1789 Manual Version 1B Printed In U S A 300 Industrial Park Road Starkville MS 39759 MFJ ENTERPRISES INC...

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