M2 Antenna Systems 393CP18 User manual

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
Tel: [phone] Fax: [phone] Web: www.m2inc.com
©2022 M2 Antenna Systems Incorporated 8/17/22
Rev.00
Model .........................................393CP18
Frequency Range.......................389-396 MHz
*Gain ..........................................14.39 dBi
Front to back ..............................22 dB Typical
Feed type ...................................“T” Match
Feed Impedance. .......................50 Ohms Unbalanced
Maximum VSWR........................1.6:1 Typical
Input Connector..........................“N” Female
Power Handling..........................1 kW
Boom Length / Dia......................80” / 1”
Maximum Element Length..........16”
Turning Radius: ..........................Call
Stacking Distance.......................Call
Mast Size....................................1-1/2” to 2” Nom.
Wind area / Survival ...................1.0 Sq. Ft. / 100 MPH
Weight / Ship Wt.........................7 Lbs. / 9 Lbs.
M2 Antenna Systems, Inc.
Model No: 393CP18
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd
FEATURES:
The 393CP18 is high performance circular polarized antenna with a remarkably clean pattern. The pattern is important in
order to match the antenna’s noise temperature with modern low noise preamps. This antenna is ideal for satellite work
but is also excellent for terrestrial uses like ATV, repeater operation, and long haul tropo DX.
The CNC machined driven element module is O-ring sealed and weather tight for low maintenance and long-term peak
performance. Internal connections are encapsulated in a space-age silicone gel that seals out moisture and improves
power handling. The 3/16” 6061-T6 rod elements are centered to minimize interaction and maintain good ellipticity.
Insulators are UV stabilized and locked in place with stainless keepers. Rugged construction, uncompromising
performance for the boom length: that’s the M2393CP18 !

393CP18 ASSEMBLY MANUAL
TYPICAL TOOLS REQUIRED: measuring tape, phillips screwdriver, 5/16”, 11/32, 7/16, and 1/2 spin-tite,
end wrenches and / or sockets. Heavy duty models may require larger sizes.
1. Lay out the boom sections and assemble using the DIMENSION
sheet as a guide for position and hardware.
2. Install the 8-32 x 1/4” set screw into each button insulator using
the 3/32” Allen wrench supplied.
3. Cut a strip of masking tape about 6” long. Fold the ends under and
stick the tape to a flat surface, stickey side up. Lay out the
elements by length and position as shown ON the DIMENSION
SHEET. Remove the REFLECTOR and find the rough center by
balancing it across finger. Push on a black button insulator to
about 1/2” from center. Insert the element through the holes at the
rear of the boom and install the second button. Install the 3/16”
rod DRIVEN ELEMENT as you did the reflector. Then continue
with the installation of the DIRECTORS. Note that the Director
Elements may not consistently diminish in length from rear
to front, so pay close attention to length and position.
4. Now begin centering the elements. Use a tape measure to
EQUALIZE the amount the element sticking out on each side of
the boom. Once centered, tighten the set screw in the insulators
on each side. After all are centered, sight down the antenna from
the rear and compare tip symmetry. Look for any obvious
discrepancies and correct if found. REPEAT THESE STEPS AND
INSTALL THE OTHER PLANE OF ELEMENTS. NOTE THEY ARE SHIFTED FORWARD ON THE BOOM
BY 1/4 WAVELENGTH.
5. Mount the special REAR DRIVEN / POLARITY SWITCH FEED BLOCK to the boom using two (2)
8-32 X 1-1/4" screws. Orient with feed and balun connectors as shown on the Dimension Sheet. The ‘T’ block
unit mounts just behind the rear REFLECTOR element with one more 8-32 x 1-1/4” screw
7. Thread a 3/8” SEAL-NUT fully onto each ‘F’ connector on each block, with black Neoprene side facing out.
Generally the balun is installed in one loop. Attach balun to the block connectors and tighten gently using a
7/16" end wrench. The two medium length cables are the !/2 wave baluns. Then back the Seal Nuts out and
finger-tighten firmly up against the face of the connectors (or tighten gently with 1/2" end wrench). Later,
after the phasing lines are installed form the balun coax and phasing lines close to the boom and secure with
cable ties (snug but not crushing or kinking the coax).
8. Install the 8-32 x 1/4” set screws )using the 3/32” Allen) wrench into the SHORTING BARS. Slide the bars
onto the 3/16” rod driven element tips and the 1/8" Feed Block Rods. Position the Shorting Bars as specified
on the DIMENSION SHEET: the distance given is between the outer face of the Feed Block and the inner
face of the Shorting Bar. Align the bars and rods with each other and tighten the sets crews. NOTE: the
shorting bar dimensions may be different on the OPTIONAL circular switched driven element.
9. Now attach the phasing cables. The long, 3/4 wavelength coax cable goes to the the front driven element. And
the short cable goes to the rear driven element. Tighten the connectors lightly with a 7/16” end wrench and
then run the seal nut up against the face to the connector and tighten just one turn past finger tight with a 1/2”
end wrench.
10. Route the cables close to the boom and avoid crossing or touching the element butts to minimize detuning.
This is a critical area if the antenna match is to be preserved. Because the cables can couple into the field of
each element set, it is important to route the cables as shown and use the cable ties provided to keep the
cables tight against the boom. THIS COMPLETES THE ANTENNA ASSEMBLY.
MASKING TAPE
OR EQUIVALENT
FACE UP
ELEMENT PREPARATION
ELEPREP
M. STAAL
5-24-05
FRONT DIRECTOR
REFLECTOR

393CP18 ASSEMBLY MANUAL
OPTIONAL MANUAL AZ-EL SYSTEM ASSEMBLY
1. Connect the two MAST CLAMPS SHELLS together loosely with four (4) 1/4-20 x 3/4” bolts.
2. Attach the mast clamps to the “TACO SHELL” ELEVATION U BRACKET using two (2) more
1/4- 20 x 3/4” bolts. Add two more 1/4-20 x 3/4 bolts, lock washers and flat washers to control the
elevation tilt angle.
3. Secure THE SPECIAL 3” X 8” X 1/4” PLATE to the elevation tilt bracket with two 1/4-20 X 3/4”
BOLTS Then add 2 SETS OF 1” SADDLES and loosely attach with 1/4-20 x 1-1/2” bolts and
locknuts.
4. Mount the AZ-EL assembly on the top of the PORTABLE FOLDING STAND and tighten the mast
clamp bolts. Now insert the rear of the antenna boom into the saddles to about 3” behind the
reflector, orient the antenna so the rear set of elements are horizontal and tighten the saddle bolts.
GENERAL GUIDELINES
For optimum performance, mount antenna high and in the clear. Always use high quality coax
and connectors. Old, corroded, or poor quality materials can SERIOUSLY affect VSWR, gain, and
pattern. If possible, test the antenna, connectors and feedline BEFORE installation. At 6' in height,
the antenna will exhibit performance approaching the specifications. If it doesn't, check feedline
and connectors for continuity and shorts. Check antenna shorting bars, element placement and
length, against Dimension Sheet.
Rear mounted antennas can generally be mounted in any polarization to any type of mast,
conductive or non-conductive.
M2ANTENNA SYSTEMS, INC.
4402 N. Selland AVE.
FRESNO, CA 93722
[phone] FAX: [phone]
www.m2inc.com Email: [email protected]

393CP18 PARTS LIST
393CP18 PARTS LIST
6-29-05
DESCRIPTION QTY
BOOM SECTION #1, 1 X .058 X 54" ............................. 1
BOOM SECTION #2, 1X .058 X 54" SOE TFS* ............. 1
ELEMENT, 3/16” ROD X SEE DIM” SHEET .................. 18
DRIVEN ELEMENT ASSEMBLY, .................................. 2
”T” BLOCK ASSEMBLY ................................................. 1
BALUN CABLE , 1/2 WAVE RG-6U ............................... 2
PHASE LINE, LONG, 3/4 WAVE RG-6U........................ 1
PHASE LING, SHORT, 1/4 WAVE RG-6U..................... 1
ASSEMBLY MANUAL..................................................... 1
IN HARDWARE BAG:
SHORTING BAR, 1/8 AND 3/16 HOLES......................... 4
BUTTON INSULATORS, SPECIAL FOR SET SCREW... 36
SCREW, 8-32 X 1-1/4 SS ................................................. 4
SET SCREW, 8-32 X 1/4, SS ........................................... 44
LOCKNUT, 8-32 SS.......................................................... 2
SEAL NUTS, 3/8-32 .......................................................... 5
CABLE TIE, NYLON ........................................................ 5
ALLEN HEAD WRENCH, 5/64” ........................................ 1
*TFS = TO FIT ITSELF
OPTIONAL CIRCULARITY SWITCH PART LIST
DESCRIPTION QTY
DRIVEN ELEMENT / POLARITY SWITCH ASSEMBLY............... 1
SCREW, 8-32 X 1-1/4” , SS.......................................................... 2
SEAL NUT, 3/8 X 32, GOLD.......................................................... 3
OPTIONAL AZ-EL MOUNTING SYSTEM
DESCRIPTION QTY
MAST CLAMP HALF......................................................... 2
ELEVATION U BRACKET (TACO SHELL) ...................... 1
COUNTERWEIGHT, 3-1/4” X 1-1/2” 4 LB ........................ 1
PLATE, 3 X 8 X 1/4” ALUM............................................... 1
SADDLE, 1”....................................................................... 4
BOLT, 1/4-20 X 4”, SS ...................................................... 1
BOLT, 1/4-20 X 1-3/4, SS ................................................ 4
BOLT, 1/4-20 X 1-1/2”, SS................................................ 4
BOLT, 1/4-20 X 3/4” ......................................................... 4
BOLT, 1/4-20 X 3/4 FLATHEAD ....................................... 3
LOCKNUT, 1/4-20, SS...................................................... 5
FLAT WASHER, 1/4”, SS ................................................. 2
LOCK WASHER, 1/4” SPLIT RING , SS .......................... 2
M2ANTENNA SYSTEMS, INC.
4402 N. SELLAND AVE.
FRESNO, CA 93722
[phone] FAX: [phone]
www.m2inc.com Email: [email protected]