M2 Antenna Systems 6M HO LOOP User manual

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
Tel: [phone] Fax: [phone] Web: www.m2inc.com
©2011 M2 Antenna Systems Incoporated 11/02/11
Rev.01
Model ........................................6M HO LOOP
Frequency Range......................50 To 50.3 MHz
Gain, Typical @ 11 ft.................4.2 dBd @ 25 deg.
Gain, 2 Stack @ 40 & 52 ft........8.2 dBd @ 6 deg.
Polarity ......................................Horizontal Omni
Impedence.................................50 Ohms Unbalanced
Power Handling. ........................800W, 1.5 kW for Stack
Feed Connector.........................SO-239
Mounting ....................................3/8-24
Vehicle Mounting Height............30” or more
Stack Distance Btwn Loops.......9ft to 12ft
Maximum Element Length.........0.1 sq ft.
Turning Radius:..........................2 lbs.
M2 Antenna Systems, Inc.
Model No: 6M HO LOOP
FEATURES:
Our new HO LOOP is a result of a continued evaluation and development on reduced size, omnidirectional HORIZONTALLY
polarized loops. This new design is easy to match in any situation. Performance is better than anything we have ever seen and its wide
bandwidth makes it immune to all weather conditions except heavy ice. Power handling is usually a problem with small loops but again
this design can handle 800 Watts with ease and a stacked pair could easily handle 1.5kW. The patterns will give you a good idea how
well the 6M HO LOOP will perform in your system. As with all horizontally polarized antennas, performance is usually tied to height
above ground but even at 10 feet the HO LOOP yields an amazing 3.8 dBd at an angle of 27 degrees. On a vehicle at 11 feet above
ground, the gain jumps to 4.2 dBd at 25 degrees! Twelve foot spacing is optimum for base station or portable use. Note the gain jumps
over 3 dB for a stacked pair with this unique antenna.
Physically the HO loop is 29.5 inches square with a wind area of just 0.1 square foot. The 3/8” diameter tubing keeps it light but
plenty rugged for mobile operation. The feed block is sealed and potted with silicon gel for extreme reliability and low loss. The feed
blocks slide on the tubes for frequency adjustment and the shorting bar adjusts for a perfect match into 50 Ohm feedline.
Two HO LOOPS can be stacked using odd quarterwaves of 75 Ohm coax into a “T”. Phase can be inverted by simply reversing the
feed block mounting as required.
Optional items include various lengths of mobile masts, our BIG FOOT monster mag base,”‘Universal Mast Mounting Kit” with ‘L’
bracket, U-bolts and misc. hardware for tower mounting. We also offer phasing cables and T connector for stacking.
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd
SUPPORT
BRACKET KIT
6M HO ONLY
MIDDLE OR TOP MOUNTING
ON 1-1/4 TO 2" MAST
UNIVERSAL MAST
BRACKET KIT
INCLUDES:
UNIVERSAL 'L' BRACKET
1-1/2 AND 2" UBOLT
3/8-24 X 1-1/2 BOLT
AND LOCKNUT

HALVES AND TIGHTEN THE
STEP #4
CAREFULLY ALIGN THE LOOP
SET SCREW LIGHTLY AT FIRST.
MAST (NOT SUPPLIED
6-32 X 1-1/4" SCREW
STEP #5 ATTACH THE SECOND
SUPPORT CLAMP ON ONE END
OF THE 3/8"SUPPORT TUBE. ADD
1 6-32 X 1-1/4" SCREW AND LOCK-
NUT. ADD THE 1/4-20 X 1" BOLT.
STEP#6 CONNECT THE OTHER END
OF THE SUPPORT TUBE TO THE
OTHER SUPPORT CLAMP WITH
A 6-32 X 1-1/4" SCREW AND
LOCKNUT. 1/2 TO 3/4" DIA.
3/8"SUPPORT TUBE
& LOCKNUT.
2-3/8" TYP.
ADJUST FREQ.
SUPPORT TUBE
THESE TUBE ENDS
ARE NOT CRITICAL AND
CAN BE CUT OFF IS
NECESSARY FOR
MAST MOUNTING.
THE ANTENNA
STOPS HERE.
3.5 TO 4" TYP.
(ADJUSTS MATCH)
& LOCKNUT 2PL.
6-32 X 1" SCREW
6-32 X 1-1/4" SCREW
& LOCKNUT.
SUPPORT CLAMP
SO-239 CONNECTOR
SUPPORT CLAMP
ADJUST UP OR DOWN
TO MAKE HO LOOP
LEVEL.
1/4-20 X 1" BOLT
STEP #2
INSTALL THE 1/4-20 X 1/4"
SET SCREWS IN THE
CONNECTOR BLOCKS
AND SLIDE ONTO THE
TUBES TO 1-1/2" TYPICAL.
3/4" X 5" POLYETHYLENE
STEP #1 SLIDE ON ONE SUPPORT
CLAMP AND CENTER AT 2-1/4"
ON TO THE WHITE CENTER
INSULATOR. INSTALL A 1/4-20 X 1/4"
SET SCREW. INSERT THE HO LOOP
TUBES INTO THE CENTER
INSULATOR. INSTALL SCREWS
AND LOCKNUTS AND TIGHTEN.
SHORTING / MOUNTING
BAR AND SET TO 4".
STEP #3
INSTALL THE 1/4-20 X 1/4"
SET SCREWS IN THE
CENTER INSULATOR.
2-1/4"
1/4-20 x 1/4"
SET SCREW
6M HO LOOP ASSEMBLY MANUAL

DURING THE TUNE UP PROCEDURE, YOU MUST BE AT 20 FEET
FROM WALLS AND OTHER LARGE OBJECTS. REMEMBER THIS IS
AN OMNI DIRECTIONAL ANTENNA AND IT HAS A LARGE FIELD.
RESONANCE AND MATCH WILL BE AFFECTED.
THE FINAL POSITION OF THE
SHORTING BAR DETERMINES
THE MATCH. A PERFECT MATCH
CAN BE ACCOMPLISHED BY
CAREFUL ADJUSTMENT.
DROPLETS OF WATER WILL
CAUSE THE LOOP TO GO DOWN
IN FREQUENCY. WE SUGGEST YOUR
BEST MATCH WHEN DRY IS AT OR
SLIGHTLY ABOVE 50.200.
1:1
1.2:1
49.0
1.5:1
50.0 51.0
TYPICAL VSWR CURVE
2:1
3-1/4 TO 4" TYP.
1/2 TO 3/4" MAST
(NOT SUPPLIED,
SOLD AS OPTIONAL ITEM)
SECOND FOR BEST MATCH
MOVE SHORTING BAR
DESCRIPTION QTY
HO LOOP 3/8" BENT TUBES 2
SUPPORT TUBE, 3/8X23.5" 1
FEED BLOCK ASSEMBLY 1
SHORTING BAR 1
CENTER INSULATOR 1
SUPPORT CLAMP 2
BOLT, 3/8-24 X 1" SS 1
LOCKWASHER, 3/8 SPLIT RING SS 1
BOLT, 1/4-20 X 1" SS 1
SET SCREW, 1/4-20 X 1/4' SS 7
SCREW, 6-32 X 1-1/4" SS 2
SCREW, 6-32 X 1" SS 2
NUT, 6-32 NYLOCK 4
ALLEN WRENCH 1/8" 1
ASSEMBLY SHEET 1
PART LIST
SUPPORT CLAMP
ADJUST UP OR DOWN
TO MAKE HO LOOP
LEVEL AFTER FINAL
TUNING ADJUSTMENTS
ARE COMPLETED.
FREQUENCY ADJUSTMENT
MOVE BLOCKS FIRST FOR
3/8 X 24 X 1" BOLT
AND FLAT WASHER
6M HO LOOP ASSEMBLY & PARTS LIST

UNIVERSAL MAST
BRACKET KIT
SUPPORT
BRACKET KIT
6M HO ONLY
INCLUDES:
UNIVERSAL 'L' BRACKET
1-1/2 AND 2" UBOLT
3/8-24 X 1-1/2 BOLT
AND LOCKNUT
BIG FOOT MAG MOUNT WITH
OPTIONAL HO LOOPS FOR
OTHER BANDS.
UNIVERT MAST BRACKET KIT
FOR 1-1/4 TO 2” MASTS
MOUNTING AND OPTIONAL KITS