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MFJ-1795 Vertical Antenna

Instructions

8

Figure 5

[ ] 16.

Ground radials should be attached

 

to the U-bolts on the Base Mounting Bracket.

[ ] 17.

The antenna should be

 

fed using a good quality 50-Ohm low-loss coax such as RG-8 or

RG-58.   Approximately 4 inches of the outer insulation should be removed.   The center
conductor of the coax should be soldered to the solder lug that was placed on the _” bolt in
step 10 of the assembly.  The outer shield of the coax should be soldered to the additional
solder lug supplied in the parts bag.  Place this solder lug onto one of the U-bolts located
on the mounting bracket Secure it using one of the _ “nuts supplied with the U-bolts.

WARNING:  

Serious burns can be received with improper use of a soldering iron.

[ ] 18.

Tune the antenna by following the instructions under the section “Frequency and SWR
Adjustment”.

[ ] 19.

Mount the antenna in its permanent location.  Slight retuning and height adjustment may 
be necessary.

USING THE MFJ 

GROUND-COUPLED™

 PORTABLE ANTENNA BASE WITH THE

MFJ-1795

The  antenna  base  should  be  assembled  using  the  instructions  supplied  with  the  unit.  The
following instructions will explain the installation of the MFJ-1795 to the antenna base.

[ ] 1.

The U-bolts should be attached to the base through the holes as indicated in Figure 5.

[ ] 2.

The So-239 connecter, supplied with the base, should then be installed on the top of the
base  plate  mount  as  indicated  in  Figure 6  using  two  6/32”  x  3/8”  screws and kep nuts
supplied with the base.  One of the feed-points at the bottom of the base may also be used.
The insulated wire supplied with the MFJ-1904 will be long enough for this application.
This will increase the radiating length of the antenna.

Summary of Contents for MFJ-1795

Page 1: ...nts while the CW ratings are generally determined by the components heating The following chart lists the power rating and the 2 1 VSWR bandwidth of this antenna Band Power Bandwidth CW SSB RTTY 40m 7...

Page 2: ...require the antenna height to be reduced An example may be the installation of the antenna inside a backyard fence for concealment Height adjustment will be discussed in the assembly section of this m...

Page 3: ...suitable eye protection In addition you will need two stable supports at least 30 tall i e saw horses or trash cans and a short 6 to 8 feet temporary mast 1 to 1 1 2 inches outside diameter for tempor...

Page 4: ...rdy enough to support the weight and the wind load ASSEMBLY AND INSTALLATION PROCEDURE During assembly of this antenna refer to the figures in this manual and the picture on Page 1 NOTE Wear safety gl...

Page 5: ...inum and place at a minimum 2 inches into the long aluminum element 5 x 1 1 8 The end of the long 5 piece used should be the one without the hole drilled in it See Figure 1 7 A hose clamp should be pl...

Page 6: ...ews until the spokes are snug Now you should be able to turn the coil assembly over and they should balance on the long spokes See Figure 3 6 32 screw Loading Coil Assembly Figure 3 IMPORTANT Do not u...

Page 7: ...dware you installed Then mount the antenna on the short temporary tuning mast or the MFJ Ground Coupled Portable Antenna Base 15 Secure the mounting bracket to the fiberglass insulator as shown in Fig...

Page 8: ...8 Tune the antenna by following the instructions under the section Frequency and SWR Adjustment 19 Mount the antenna in its permanent location Slight retuning and height adjustment may be necessary US...

Page 9: ...ushing SO 239 Anetnna Base 3 The plastic bushing supplied in the parts should be placed in the hole under the SO 239 connector 4 Now the 15 piece of insulated wire should be passed through the plastic...

Page 10: ...berglass insulator may necessary REMOVING THE ANTENNA FROM THE BASE OR BRACKET The antenna may be quickly removed to be hidden from view This is easily accomplished by loosening the hose clamp at the...

Page 11: ...he antenna to test the feed line If the SWR checks good the antenna assembly will have to be checked for proper assembly shorts or openings at the feed point of the antenna If the antenna operates nor...

Page 12: ...the frequency change 40 M 1 trimmed off each of the spokes equals approximately 130 KHz 20 M 1 trimmed off each of the spokes equals approximately 500 KHz 15 M 1 trimmed off each of the spokes equals...

Page 13: ...MFJ 1795 Vertical Antenna Instructions 13...

Page 14: ...f the manual does not reference your problem or your problem is not solved by reading the manual you may call MFJ Technical Service at 662 323 0549 or the MFJ Factory at 662 323 5869 You will be best...

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