MFJ-1895

2 Element Moxon Beam for 15 meters

INSTRUCTION MANUAL

CAUTION: Read All Instructions Before Operating Equipment

300 Industrial Park Road

Starkville, MS 39759 USA

Tel: 662-323-9715 Fax: 662-323-6551

GENERAL DESCRIPTION

The Moxon Rectangle is a close-spaced 2-element Yagi consisting of a driven element and a reflector with the element tips folded toward each other to reduce turning radius.

The Moxon features a broad cardioid pattern with roughly 3.3 dBd of foward gain and front to back ratio measuring -30 dB or more. Spanning just over 17 feet and weighing only a few pounds, it is well suited for rooftop installations using lightweight TV hardware.

Choosing a location

For best performance on receiving and transmitting, mount the antenna in a clear location above or away from buildings, towers, feedlines, utility wires, and other antennas. While your own ingenuity and particular circumstances will determine the final mounting method, we’ll pass along a few ideas for both permanent installation and portable operation.

Never mount this antenna in a location that will permit unsuspecting people to come in contact with the antenna elements.

Never mount this antenna where a mechanical failure might allow the antenna to contact power lines or other utility wires.

Always ground the feedline at the point where it enters a building to a good earth ground for lightning protection.

WARNING Always mount this antenna so that it is out of reach of adults and children.

The elements can cause injury and/or severe RF burns.

WARNING

WHEN INSTALLING YOUR SYSTEM, TAKE EXTREME

CARE TO AVOID ANY ACCIDENTAL CONTACT WITH

POWER LINES OR OVERHEAD OBSTRUCTIONS.

FAILURE TO EXERCISE THIS CARE COULD RESULT

IN SERIOUS OR FATAL INJURY

Permanent Installation

The ideal installation is a rigid pole or roof mount that puts the antenna completely in the clear. If the ideal installation is not possible, choose the best compromise.

TV mast, heavy-duty rigid electrical conduit, and steel water pipes are suitable mast materials. The use of soft or thin wall mast is not recommended.

Portable Operation

The MFJ-1895 may be easily transported to temporary locations for portable, emergency, and contest operation. Even for temporary or portable operation, do not be casual about selecting a suitable mast. If the antenna falls, it can be damaged and may cause serious injury. Whatever type of installation you choose, remember that the antenna should be installed where it cannot be contacted by people or animals or come in contact with power lines.

2

Antenna Assembly

Assemble the antenna on a flat level surface. Avoid assembly over grass as you may drop some of the parts and never find them again. You may use a couple of saw horses or other means of support to aid assembly. Loosely assemble the #1 and #2 brackets using the 1/4-20 nuts, bolts and washers as shown in figure 1. Don't forget the square nuts that go inside the brackets.

36,38

30,37

2

28

Assemble the boom to mast bracket as shown. The 2 boom tubes should meet in the middle of the bracket. You don’t have to put the bracket on a mast yet if your using saw horses to support the antenna. Tighten the 1/4-20 bolts securely.

2

2 1-1/4 x 39 boom tube

28 1/4-20 x 3/4 bolt

30 1/4-20 hex nut

36 5/16 nut

37 1/4 lock washer

38 5/16 split washer

29

28

Allow the tube to protrude

1 inch from the edge of the bracket.

19

2

33

29 1/4-20 x 3/8 bolt

28 1/4-20 x 3/4 bolt

2 1-1/4 x 39 boom tube

37 1/4 internal lock washer

30 1/4-20 hex nut

33 1/4-20 square nut

19 #2 element bracket

29 37

30

Figure 1

3

Install the 7/8 elements into the bracket while it is loose on the boom. Tighten them enough to hold the element but allow for the bracket to rotate on the boom as you will have to align the elements with the mast when the antenna is fully assembled.

20

29

28

29 1/4-20 x 3/8 bolt

28 1/4-20 x 3/4 bolt

33 1/4-20 square nut

37 1/4 internal washer

30 1/4-20 hex nut

24 1-1/4 to 7/8 insulator

3 7/8 x 36 tube

27 #6 hose clamp

1 5/8 x 38 tube

24

3

33

27

1

29 37

30

Figure 2

Secure the driven element insulator to the other end of the boom also allowing 1 inch from the edge of the bracket to the end of the boom. Install the remaining two main elements to the insulator as shown in figure 2. Leave the bracket loose enough to align the elements when the antenna is finished.

Short end

37”

#4 hose clamp

Assemble the end elements as shown in figure 3.

Use the #4 hose clamps to secure the tubing together. The corner tubes have one side longer than the other. The short end should point toward the boom. Repeat this assembly again to make the other side of the antenna.

7/16 x 34”

7”

29”

7/16 x 26”

7/16 x 34”

Short end

Figure 3

Driven Element

4

190012 5/8 x 38”

190210 7/8 x 36”

#6 Hose

Clamp

REFLECTOR ELEMENT

190210 7/8 x 36”

#6 Hose

Clamp

DRIVEN ELEMENT

1 inch

Figure 4

Install the end pieces onto the elements using the #4 hose clamps. Sliding these end pieces in and out will be how you adjust the final length of each element. Measure the distance from the center of the boom to the outside of the element. This distance will be the same for all four elements. Use the antenna diagram on the next page to verify all your measurements. Place the 1-1/4 end caps on each end of the boom.

25

35

32

35 10-24 x 1” bolt

32 10-24 hex nut

37 #10 internal lock washer

25 7/8 tube clamp

37

Figure 5

3/4”

Attach the feed line to the driven element as shown in figure 5. Place the 7/8 clamps

3/4 inch away from the insulator. Use the 10-24 bolts nuts and lock washers to tighten the clamps to the tube. Place the feed line eyelets over the remaining section of the bolt and secure with another lock washer and nut. Secure the coax to the boom with electrical tape or other suitable fasteners.

5

37 xxxxxx 7/16 x 34”

29”

1-1/4 x 39”

72 inches

1-1/4 x 39”

DIRECTION OF

RF ENERGY

Figure 6

6

Final Assembly

Check the alignment of the elements and make sure all hardware is tight. Mount the antenna in the final location.

Connect the coax balun to a high quality low loss cable such as LMR-400 or equivalent.

SWR Check

Resonance can be checked with an MFJ-256 or MFJ-269. Alternately a transceiver and

SWR meter can be used. Resonance may be changed by adjusting the length of the elements.

If the resonance point is too low, shorten the element length. If the resonance point is too high, lengthen the element length.

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 fo 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 allowing hazardous voltages that could create a shock hazard.

Adequate protection can be accomplished by grounding the shield of the coax to a good earth ground where it enters the building, or directly burying the cable in the earth for several feet before it enters the building. For maximum lightning protection, the coaxial cable should be totally disconnected from the station during threatening weather conditions.

7

19

20

7

8

21

22

3

4

1

2

5

6

190012

20-1895-1

190210

20-1895-3

20-1895-4

20-1896-5

20-1890-6

13-1890-1

165141

165138

385142-1

385144-1

PARTS LIST

Tube 5/8 x 38 swaged ----------------------------------------------

Tube, Boom, 1-1/4 .058 x 39”-------------------------------------

Tube, 7/8 x 36” swaged ---------------------------------------------

Tube, 7/16 x .028 x 34” slotted ----------------------------------

Tube, 7/16 x .028 x 26” slotted ---------------------------------

Tube, 3/8 corner ---------------------------------------------------

2

4

4

6

4

2

Rod, Fiberglass 3/8 x 9” -------------------------------------------

Balun Assembly ------------------------------------------------------

Bracket, # 2 ---------------------------------------------------------

Bracket, # 1 ----------------------------------------------------------

Boom Bracket --------------------------------------------------------

Boom Bracket --------------------------------------------------------

2

2

2

1

1

1

17-1895-1

32

33

34

35

28

29

30

31

36

37

23

24

25

26

27

38

745-3104S

463767

163312

455630

745-3106S

505266

500156

554099

711-1037S

554071

551367

540067

504069

555747

562961

564792

Parts Pack MFJ-1895

Hose Clamp #4 ------------------------------------------------------

Insulator 1-1/4- 7/8 ------------------------------------------------

Tube Clamp, 7/8 ----------------------------------------------------

Caplug, 1-1/4 ABS ------------------------------------------------

Hose Clamp #6 -----------------------------------------------------

Bolt, 1/4-20 x 3/4 ---------------------------------------------------

Bolt, 1/4-20 x 3/8 ---------------------------------------------------

Nut, 1/4-20 Hex -----------------------------------------------------

Washer, #10 Internal lock -----------------------------------------

Nut, 10-24 Hex ------------------------------------------------------

Nut, square 1/4-20 -------------------------------------------------

U-bolt ------------------------------------------------------------------

Bolt, 10-24 x 1 ------------------------------------------------------

Nut 5/16 --------------------------------------------------------------

Washer, 1/4 Internal lock ----------------------------------------

Washer 5/16 split -------------------------------------------------

4

20

2

2

4

4

20

4

20

4

16

2

2

2

4

4

8

SITE SELECTION

2. Add this length

3. Double

TOWER towers always use a safety belt made of

The safe distancef rom power lines should be at least twice the height of the antenna and mast combined.

MOUNTING

SUPPORT

METHOD

However is your first concern. Some

ROOF MOUNTEO nient mounting place. But the chimney must be strong enough to support the antenna in high winds. Do not use a good chimney foot, 1-114" course of bricks, and the lower bracket two or three feet below the upper bracket.

ets as far apart as possible.

NOTES

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.

1.

The purchaser must retain the dated proof-of-purchase (bill of sale, canceled check, credit card or money order receipt, etc.) describing the product to establish the validity of the warranty claim and submit the original of machine reproduction or such proof of purchase to MFJ Enterprises, Inc. at the time of warranty service. MFJ

Enterprises, Inc. shall have the discretion to deny warranty without dated proof-of-purchase. Any evidence of alteration, erasure, or forgery shall be cause to void any and all warranty terms immediately.

2.

MFJ Enterprises, Inc. agrees to repair or replace at MFJ's option without charge to the original owner any defective product under warrantee provided the product is returned postage prepaid to MFJ Enterprises, Inc. with a personal check, cashiers check, or money order for $7.00 covering postage and handling.

3.

MFJ Enterprises, Inc. will supply replacement parts free of charge for any MFJ product under warranty upon request. A dated proof of purchase and a $5.00 personal check, 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 tested

PC board product is returned. Wired and tested PC boards installed in the owner's cabinet or connected to switches, jacks, or cables, etc. sent to MFJ Enterprises, Inc. will be returned at the owner's expense unrepaired.

7. Under no circumstances is MFJ Enterprises, Inc. liable for consequential damages to person or property by the use of any MFJ products.

8.

Out-of-Warranty Service: MFJ Enterprises, Inc. will repair any out-of-warranty product provided the unit is shipped prepaid. All repaired units will be shipped COD to the owner. Repair charges will be added to the COD fee unless other arrangements are made.

9.

This warranty is given in lieu of any other warranty expressed or implied.

10.

MFJ Enterprises, Inc. reserves the right to make changes or improvements in design or manufacture without incurring any obligation to install such changes upon any of the products previously manufactured.

11.

All MFJ products to be serviced in-warranty or out-of-warranty should be addressed to MFJ

Enterprises, Inc., 300 Industrial Park Road, Starkville, Mississippi 39759, USA and must be accompanied by a letter describing the problem in detail along with a copy of your dated proof-of-purchase.

12.

This warranty gives you specific rights, and you may also have other rights which vary from state to state.

300 Industrial Park Road

Starkville, MS 39759 USA

Tel: 662-323-9715 Fax: 662-323-6551