MFJ MFJ-1762 User Manual

MFJ-1762 Instruction Manual

Six-meter Yagi

MFJ-1762 Instruction Manual

INTRODUCTION

Thank you for purchasing the MFJ-1762 three-element six-meter Yagi. The MFJ-1762 is a light-weight directional antenna especially designed for installation with readilyavailable TV-type masts, mounts, and hardware. The driven element employs a "no-tune" hairpin impedance matching system, and all elements are cut to exact length at the factory. No adjustment should be needed for coverage of the 50-MHz SSB band (see page 8 for FM-segment tuning instructions). Because of its compact size, light weight, and unique construction, the MFJ-1762 is also a excellent choice for six-meter portable or "rover" operation. In weak-signal DX applications, two MFJ-1762s may be stacked for increased capture area and 3-dB additional gain. The MFJ-1762 has been computer modeled on both ELNEC and YA to confirm design integrity, and has been thoroughly field tested in northern climates for winter survivability.

TYPICAL SPECIFICATIONS
Boom length	6'
Turning Radius	5' 8"
Longest Element	117-1/2"
Weight	2.5 lbs.
Feed Impedance	50Ω
Resonant Frequency	50.3 MHz
1.5:1 VSWR Bandwidth	1.7 MHz
Forward Gain	6.0 dBd (8.2 dBi)
Front-to-Rear Ratio	>18 dB measured
Maximum Power	150 Watts

SAFETY PRECAUTIONS

Before assembling, please read the following safety notice:

This antenna is an electrical conductor--do not handle or mount near power lines, service entrances, or other dangerous power sources. Mount out of the reach of adults, children, and animals. Antenna elements develop lethal voltages and may cause severe RF burns during transmitter operation. For lightning protection, always ground your supporting mast to two or more outdoor ground rods. Disconnect the feedline from your radio when not in use. Do not expose pacemakers or other bio-medical equipment to strong RF radiation. To avoid personal injury or damage to the antenna, plan all mechanical aspects of your installation carefully. Avoid handling heavy or unwieldy masts by yourself, and make sure a second person is available to assist you in an emergency. Never work on a roof or climb a tower alone!

1

MFJ-1762 Instruction Manual

Six-meter Yagi

MFJ-1762 PARTS LIST

To begin, confirm that all necessary parts have been supplied with your antenna package:

(1) - 6' x 1-1/8" OD boom

(2) - 54" x 1/4" OD element section (director)

(2) - 54-1/2" x 1/4" OD element section (driven element)

(2) - 59-1/4" x 1/4" OD element section (reflector)

(1) - 5/16" x 1/4" OD spacer

(1) - hairpin inductor

(2) - "L" bracket

(1) - 1 3/4" x 6-32 screw

(6) - 1/2" x 10-32 screw

(2) - 1/2" x 6-32 screw

(1) - 6-32 Kep-nut

(2) - 6-32 nut

(2) - 6-32 flat washer

(2) - 6-32 lock washer

(4) - Insulated polyethylene element-mounting grommets

(2) - #6 solder lug

(1) - 1 - U-bolt mounting hardware kit (U-bolt, mast clamp, nuts)

(1) - Tube of Locktite

If any parts are damaged or omitted, please contact MFJ Technical Service at 601-323- 0549 or the MFJ Factory at 601-323-5869 to arrange for replacement.

TOOLS

You'll need a selection of common household tools to construct your antenna:

•Phillips-head screw driver (#2)

•Straight-blade screw driver

•Pliers

•	Utility knife or Ex-acto knife with #11 blade
•	Soldering Set-up

SUGGESTED ANTENNA MATERIALS

•RG8-M Coax (also RG59 if stacking antennas)

•Sealant (Seal-All ) or equivalent

•Plastic electrical tape

SUGGESTED TEST EQUIPMENT

• MFJ-259 RF Analyzer or VSWR bridge

2

MFJ-1762 Instruction Manual

Six-meter Yagi

CONSTRUCTION:

[ ] Begin by laying the boom on a flat surface. Find the driven-element holes and the two sets of mast-mount holes (one for vertical and one for horizontal mounting). The mast-mount holes are toward the reflector end of the antenna. Identify the director and reflector ends of the boom before starting assembly.

[ ] Find two (2) 54" director element sections and identify the tapped end of each. Insert the tapped ends into the 1/4" holes drilled at the director end of the boom. Secure each in place with 10-32 screws. If you do not anticipate disassembling your beam, apply a drop of Locktite to each screw. Grip the element section gently with pliers when tightening.

35-1/4"

35-1/4"

	Director	Driven Element	Reflector
			117-1/2" tip-to-tip
	107" tip-to-tip	108-1/4" tip-to-tip

Driven Element

Mounting Holes

		Mast
		Mounting Clamp
#10 Screw	Hairpin Inductor	Boom

3