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MFJ-1768 Dual Band Yagi                                                                       Instruction Manual 

7  

10- Lay the antenna on a flat surface to install the thin capacitor plates for the 2 meter driven elements.  
Insert a 4-40 x 1/2" screw through the hole located in the middle of the element, pass it through a thin 
capacitor plate.  Thread a 4-40 nut on the screw and tighten.  Repeat this procedure for the second 
driven element (see Figure 3). 
 

IMPORTANT:  Make sure the capacitor thin plates form a 90 degrees angle with the 2 meter 
driven elements 
 

11- The antenna is ready now to be mounted on the permanent mast and ready to be used on the air. 
 

Note:

  

Make sure to dress the feed coax cable along the boom and run it along the permanent 

mast.  Hold it in place using either electric tape or black cable ties  

Tuning 

 
The MFJ-1768 is pre-tuned on both bands, additional tuning is not required.  The antenna bandwidth is 
very wide, it covers the entire 2 meter and 70 centimeter band with an SWR less than 2:1. 

Grounding Considerations 

 
Although this antenna is designed to operate efficiently without the requirement of an earth ground, 
SAFETY GROUNDING MUST STILL BE PROVIDED to protect equipment, property and persons 
from the hazards of lightning strikes and other weather related electrical discharges.  In addition the  
coaxial cable feeding the antenna should have the shield grounded to eliminate the risk of any indoor 
equipment failure from allowing hazardous voltages from appearing indoors and creating a shock 
hazard. 

 

FIGURE 6

 

 

FIGURE 5

 

Summary of Contents for MFJ-1768

Page 1: ...ruction Manual Table of Contents Introduction 2 Choosing a Location for the Antenna 2 Tools and Time Requirements 3 MFJ 1768 Parts List 3 Safety Precautions 3 Assembly and Installation 4 Tuning 7 Grounding Considerations 7 Maintenance 8 Technical Assistance 8 ...

Page 2: ... band antenna there is no need to switch antennas when changing bands With the use of a duplexer such as the MFJ 916 you can connect two different radios two different bands to the MFJ 1768 at the same time Choosing a Location for the Antenna The MFJ 1768 can be mounted on any 1 to 1 1 2 mast conductive or non conductive capable of supporting the weight of the antenna and the torque developed by t...

Page 3: ...One bag containing the following hardware Twenty 3 16 ID insulators 30 push nuts 3 16 ID Two 1 1 8 red end caps One U bolt and saddle clamp assembly Push nut assembly tool Two capacitor thin plates for 2 m elements Two 4 40 x 1 2 SST screws Ten 4 40 SST nuts One 1 1 8 diameter 6061 T6 aluminum tubing boom Safety Precautions WARNING This antenna is an electrical conductor Contact with power lines c...

Page 4: ...nstallation During assembly of this antenna refer to figures in this manual and the picture on the front cover The assembly instructions tell you step by step how to install the insulators the driven and parasitic elements and the U bolt assembly All parasitic elements for 2 meter and 70 cm band are color coded at their ends and alphabetically labeled on figure 1 and on figure inside front cover t...

Page 5: ... start the assembly of the driven elements as follows A The 2 meter driven element Align the holes drilled on the end of a 19 1 4 x 1 4 tube with the 4 40 screws located on the rear end of the feed plate see figure 3 for exact location Insert the 4 40 screws into these holes Thread 4 40 nuts over the two screws and tighten to ensure good connections Repeat the same procedure for the remaining 19 1...

Page 6: ...or section 7 and 8 refer to figure 1 figure 4 and figure 5 while assembling 7 Insert element A black end from GROUP 1 into its designated hole in the boom as shown in the figure on the inside front cover Assemble another push nut from the other side see figure 4 and figure 5 and slide it until it reaches the 3 16 black insulator Make sure that the element is secured in place with minimum free play...

Page 7: ...e boom and run it along the permanent mast Hold it in place using either electric tape or black cable ties Tuning The MFJ 1768 is pre tuned on both bands additional tuning is not required The antenna bandwidth is very wide it covers the entire 2 meter and 70 centimeter band with an SWR less than 2 1 Grounding Considerations Although this antenna is designed to operate efficiently without the requi...

Page 8: ...through the threads and protect the connectors from corrosion THIS IS THE SAME TYPE OF SEALER THAT COMMERCIAL ANTENNA INSTALLERS AND CATV COMPANIES USE WITH GREAT SUCCESS A less desirable but still adequate sealer is the automobile seam sealer commonly sold as coax seal This is a pliable black sealing compound When installing any coax seal NEVER completely cover the barrel of the coax connector Th...

Page 9: ... cashiers check or money order must be provided to cover postage and handling 4 This warranty is NOT void for owners who attempt to repair defective units Technical consultation is available by calling 601 323 5869 5 This warranty does not apply to kits sold by or manufactured by MFJ Enterprises Inc 6 Wired and tested PC board products are covered by this warranty provided only the wired and teste...

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