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1.Insert the 1/4-20 x 1/4" set screws a few threads into the two connector blocks. Use the 1/8" Allen 
wrench provided. Insert the 1/4-20 x 1/4" set screws a few threads into the ends of the shorting bar.  
 
2. Refer to the 

HO-LOOP

 ASSEMBLY SHEET and insert the tubes into the two connector blocks as 

shown. Slide on the shorting bar, align the loops and GENTLY tighten the 1/4-20 x 1/4" set screw onto 
the tubes. Slight bending of the tubes will ensure that all tubes are straight and square to each other.  
Be sure the blocks are set to the starting ’A’ dimension. The ‘A’ dimensions controls the FREQUENCY. 
 
3. Set the shorting bar to the ‘B’ dimension shown and tighten gently.  When complete check match and 
tighten . The ‘B’ dimension controls the MATCH 
 
4. Once the loop is assembled either final tune it in its final position on your vehicle or if tower mounted, 
simulate the mast size and other conditions to minimize final tuning in position. 
 
4. That is about it. A 3/8-24 x 1" bolt and washer is provided to attach the 

HO LOOP

 to any standard 

mobile mast or any M2 mast available as an option. 
 

REMEMBER, HORIZONTALLY POLARIZED ANTENNAS ARE AFFECTED BY THE GROUND SO 
THE HIGHER YOU AND GET YOUR HOOP  LOOP
 THE BETTER. 

The ground can be your friend as 

well providing as much as 6 dB additional ground gain at some angle above the horizon. That angle is 
defined by the frequency and height above ground. At one wavelength, 80" at two meters, the typical 
angle of maximum radiation will be about 14 degrees. At two wavelengths, the angle is 7 degrees and 
at 4 wavelengths ( 27 ft.), the angle is 3.5 degrees. Net gain improves with height because the pattern 
hits the ground at a more grazing angle giving up less energy to the ground. 
 
In most mobile installations 10 to 11 feet is about the practical limit for most driving conditions. The HO 
LOOP works at just 18" above a vehicle roof and contacts out 200 miles are quite common. However 
you will find more people to talk to and longer if you can get the 

HO LOOP

 up at the 10 foot level. 

 
POWER CONSIDERATIONS : 10 Watts into the HO LOOP  will do well out to about 80 miles. 150 
Watts gets you into that 200 mile category and 350 to 400 Watts get to the 300-400 and you will enjoy 
much longer QSO's on a regular basis. From a hill top location 600-800 mile QSO's have been reported 
several times. We hope you enjoy your new 

HO LOOP

 and please keep an ear out for those rare but 

wonderful skip openings to other parts of the country! 
 
Contact M2 for optional items available for your 

HO LOOP

 
 

M

2

 ANTENNA SYSTEMS, INC. 

4402 N. Selland Ave. 

Fresno, CA 93722 

(559) 432-8873  Fax: 432-3059 

www.m2inc.com

 Email: 

[email protected] 

2M HO LOOP ASSEMBLY MANUAL 

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