M2 Antenna Systems 2M7X, Быстрый старт

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8. Install the 8 - 32 x 1/4” set screws (internal Allen head - tool supplied) into the SHORTING BARS.
Slide the bars onto the 3/16” rod driven element tips and then onto the Driven Element Block
Rods. Position the Shorting Bars as specified on the Dimension Sheet: 2 - 9/16” from the outer face
of the block to the inner face of the bar. Align the bars and rods with each other and tighten the set
screws.
9. The boom to mast plate is normally mounted at the balance point. Since the feedline represents
significant weight it is best to have it attached and fastened along the boom with cable ties before
final mounting of the plate. Use two 1" U - bolts and the stainless nuts and lock washers provided
(no cradles are used). DO NOT OVER TIGHTEN. 2” U - bolts are provided for mounting the
antenna to your mast. Never mount to a metallic mast or cross boom in the same plane as the
elements. Pattern and performance will deteriorate. See next step.
10. INSTALLATION AND TESTING STACKING INFORMATION
A . To protect your investment in this high performance antenna, always use high quality coax and
connectors. Old, corroded, or poor quality materials are common sources of serious performance
losses.
B . Test the antenna, connectors and feedline, BEFORE installing to your mast or tower. At 6 feet
or more the antenna will exhibit VSWR similar to higher mounting heights. Set antenna on a
ladder or temporary mast. Check for continuity and match across the band. It should be close to
“ spec ” across the rated bandwidth. When satisfied, add the second SHAFT RETAINERS as
described in step 5.
C. STACKING REMINDERS:
1. All driven element blocks MUST be oriented to the same side of boom.
2. All boom - to - mast plates MUST be mounted at the same point on the boom.
3. Feed / phasing lines MUST be of equal electrical length or multiples of 1/2 wavelength in order
to maintain equal phasing in the array. Improper phasing can severely deteriorate performance.
4. As a general rule, you never want to have metallic structures, such as a mast or feed lines
parallel to the elements unless it is behind the reflector. Having metallic structure in the same
plane as the elements in front of the reflector element can cause VSWR problems and or skewed
patterns.
FOR HORIZONTAL POLARIZATION , the antenna may be mounted to a METALLIC vertical mast
or a horizontal NON - METALLIC cross boom. If mounted to a horizontal cross boom, route the
feedline forward to the boom - to - mast plate, loop down, and bring back to cross boom at least 6”
beyond element tips. Antennas are typically stacked one above the other in horizontal polarity.
SEE SPEC SHEET FOR STACKING DISTANCE. See Stacking Reminders.
FOR VERTICAL POLARIZATION , the antenna may be mounted to a NON METALLIC
VERTICAL MAST or a horizontal METALLIC cross boom. If mounted to a NON METALLIC
vertical mast, Turn the driven element 180 degrees so the feed line and “ N ” connector is facing to
the rear of the antenna, route the feed line to the rear of the antenna keeping 4” to 6” behind the
reflector element. Let the cable droop at least 6 inches BELOW THE VERTICAL ELEMENT TIPS.
Re - attach the feed line to the mast below the element tips. A simple structure can easily be
fabricated if you want something to support the feed line. See M2 “ L ” brace kit for ideas. Vertically
polarized Antennas are typically stacked side by side on a horizontal cross boom. See Stacking
Reminders.
If you are unsure about stacking multiple antennas, please call M
2
and let us help you DO IT
RIGHT! Visit our website, https://www.m2inc.com/blog/ for other tips.
2M7X ASSEMBLY MANUAL