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MFJ-1795 Vertical Antenna

Instructions

6

[ ] 10.

Place one of the hose clamps around the aluminum tubing and snug the clamp using a
5/16” nut driver .  The center conductor of the coax will be connected to the antenna using
a solder lug placed under the clamp. Refer to figure 2.

[ ] 11.

Install the short 6/32” screws in the rings of the loading coil assemblies and place a 6/32”
nut on each screw.  Put the four medium capacitance spokes in the four holes on the rings
of the coil assembly. Then, tighten the screws 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 use a high torque electric screwdriver to mount the capacitance

spokes. The screw heads will be sheared off if too much torque is applied.

[ ] 12.

Install four short capacitance spokes in the next 3 sets of rings. Again, tighten these spokes
as was done in step 9. (See Figure 3)

[ ] 13.

Slide a hose clamp over the top radiator.  Mount the top coil assembly to the antenna by
inserting the fiberglass insulator in the top radiator.  Tighten the metal strap from the coil
assembly under the hose clamp. See Figure 4.

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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