Directive Systems & Engineering DSEFO222-16 User manual

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DSEFO222‐16Rev12/13
DirectiveSystems&Engineering
2702RodgersTerrace
Haymarket,VA20169‐1628
www.directivesystems.com
703‐754‐3876

16Element3.9wl.K1FODesignedYagi,ModelDSEFO222‐16
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ELECTRICALSPECIFICATIONS
Frequency range: MHz ...................... 222-224
Gain: dBd........................................... 14.0
Impedance: Ohms.............................. 50
Connector type................................... Type N (F) UG-58/U
Front -to- back ratio: dB...................... 22
SWR: Typical at resonance................ ≅1.2:1
Beamwidth: degrees
E- Plane ................................. 31°
H- Plane ................................. 33°
Sidelobe level: decibels
E- Plane ................................. -18
H- Plane ................................. -16
Power rating, Continuous: Watts ...... 1000
Stacking Distance: ft.(m)
E- Plane.................................. 8’9” (2.667)
H- Plane................................. 8’ (2.438)
MECHANICALSPECIFICATIONS
Boom length: in. (m.)........................... 17’4” (5.28)
Turning radius: in. (m.)........................ 10’4” (3.15)
Weight Assembled: Lbs (kg.).............. 9.5 (4.32)
Max mast size: in. (cm.)....................... 2 (5.08)
Wind surface area: Ft (m. ) ................. 1.4 (.13)
Wind Survival: Mph (km/hr)................. 100 (160)
PARTSLIST
Boom BAG #2
1 1/4" OD x 0.058 x 72" rear boom 1 Element Insulator 34
w. coax/ balun assy. attached Keepers, s.s. 3/16" 36
1 3/8" OD x 0.058 x 72" front boom 1
BAG #3
Element bundle U-bolt , s.s. 5/16-18 x 2” 2
16 elements w. 2 T-match rods 1 U-bolt, s.s. 1/4-20 x 1 1/2” 2
Nut, hex, s.s. 5/16-18 4
HARDWARE BAG #1 Lock washer, split, s.s. 5/16” 4
Hose clamps, stainless steel 2 Lock nut, s.s. 1/4-20 4
8-32 x 1 3/4" machine screw 2
8-32 s.s. hex nut 2 Boom to Mast plate 1
#8 split s.s. lock washer 2 Assembly instructions 1
Brass T match bars 2

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DSEFO222‐16Rev12/13
CAUTION: Whilewestrivetoremoveallburrsfromallmachinedparts,thereisalwaysthepossibilityof
sharpedges.Westronglysuggestcheckingtheedgesanduseafinefile,or400grit
sandpaper,toremoveanyburrsthatmayhavebeenleft.

Toolsneeded: #2Phillipsscrewdriver
¼”flatbladescrewdriver
solderinggunorlargeiron
rosincoresolder
largeneedlenosedpliers
keeperinstallationtool(suppliedwithkit)
rulerwithmetricmillimetermarkings
markingpencil
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ASSEMBLYINSTRUCTIONS
The antenna components should be removed carefully from the shipping container and
the individual parts counted and checked for completeness. Be careful to check all tubing
pieces for elements and hardware that may be packed inside.
The boom consists of three pieces of tubing. The rear boom section has the driven
element connector and balun already preassembled and attached. The larger diameter center
boom section (1 3/8" dia.) must be connected to the rear section. Insert rear section where
marked "JOINT A" and adjust to the marking line. Align the #8 hardware mounting holes and
slide the stainless steel worm clamp over the slotted portion of the center boom piece. An 8-32
X1 1/2" machine screw, lock washer and hex nut complete the process. Tighten all hardware
then proceed with the front boom piece. That connection with the mid boom piece is marked
"JOINT B".
The element bundle contains all of the elements needed for assembly. Take time to
inventory each one and check off each dimension with Table 1. Some elements vary by 1 or
2mm in overall length, so extreme care in measuring is called for here. Arrange elements in
order of descending size and mark each element with a scribe for proper location of the
"keeper" (see Table 1 and Figure 1). The reflector is the longest element, and each
succeeding director is slightly shorter. DIR # 14 is the shortest. The keeper must be installed
as shown in Fig. 2.Using the aluminum tubing tool supplied, slide the keeper to within 1/8" or 3
mm. of the scribed line. Final adjustment will be done on the antenna. Note that the keeper is
a one way device only. If you go past the scribed line you must continue to the element end
and start the process over. Place the first keeper on all elements.
.
The element bundle contains all of the elements needed for assembly. Take time to
inventory each one and check off each dimension with Table 1. Some elements vary by 1 or
2mm in overall length, so extreme care in measuring is called for here. Arrange elements in
order of descending size and mark each element with a scribe for proper location of the

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DSEFO222‐16Rev12/13
"keeper" (see Table 1 and Figure 1). The reflector is the longest element, and each
succeeding director is slightly shorter. DIR # 14 is the shortest. The keeper must be installed
as shown in Fig. 2.Using the aluminum tubing tool supplied, slide the keeper to within 1/8" or 3
mm. of the scribed line. Final adjustment will be done on the antenna. Note that the keeper is
a one way device only. If you go past the scribed line you must continue to the element end
and start the process over. Place the first keeper on all elements.
You are now ready to install the elements on the boom. You must start at one end and
work your way, in order, to the far end of the boom. Lay out the elements in ascending or
descending order as appropriate. Install a black insulator in each side of the boom piece at
the starting end, and slide the correct element through the two insulators. Obtain a second
keeper and install that keeper on the opposite end of element #1 from the pre installed keeper.
(See Figure 3) Check that the element is centered before you snug up both keepers. A
positioning error of +/- 1mm. or 0.040" is acceptable. At this point, if you tighten the keepers
and the element is not centered, you will have to cut one of the keepers to remove the element
and start again. Some extra keepers are supplied, but care is definitely required here. Check
your work as you go! Proceed with the next element in similar fashion. Note that the driven
element is brass tube, but otherwise is installed as the other elements. Check off each
element on Table 1 to monitor your progress. Double-check element lengths one last time
before final installation on the boom.
The driven element and T-Match assembly are built as shown in Figures 4 & 5.

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DSEFO222‐16Rev12/13
Locate the two brass T-arms. Both are preformed- one is straight with a flattened end,
while the other is bent and flattened on one end. Locate also the brass T-match bars, and
position them on the brass driven element as shown in figure 4.Match bars and position them
on the brass driven element as shown in Figure 4.
Install the two T-match rods on the T-match bars and connect the formed and flattened
ends to the preassembled standoff insulators (Figure 4 &5). Solder the flattened T-match rod
ends to the standoff insulators only. The bent or formed T-match rod is inserted into the solder
cup of the Type N(UG-58/U) connector and soldered. If you are installing multiple antennas in
an array, be sure you locate the formed wire on the same T-Match side for each antenna.
Proper phase relationship here is important. Align the two brass T-Match bars on the driven
element parallel with the edge of the connector and bracket. Adjust the T-Match dimensions
as shown in Figure 4 & Figure 5 by sliding the bars carefully along the driven element to the
proper point. Be careful to not apply force to the standoff insulators (easily broken!) You may
have to bend the connector bracket slightly to achieve the dimensions listed in the figure.
Carefully form the pre trimmed balun center leads around the T-Match rods as shown in
Figure 4 and 5. Be careful to bend the stiff center conductor without deforming the rods. Use
needle nose pliers. Solder the balun connection on each side.

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DSEFO222‐16Rev12/13
Trim the excess T-Match rods as shown in Figure 4. 10.90" or 277mm is the proper
dimension as measured from the midpoint of the connector to the end of the wire. The T-
Match bars should be now set to the indicated position in Figure 4. Note that they are slightly
tilted.
If you wish to check your work, now is the time to apply power to the antenna. Any
workaround RF energy should be done carefully. We do not recommend standing next to an
antenna with many watts of 222 MHz energy radiating around it. The best method involves
using a low power return loss bridge and SWR indicator along with a signal generator. A
power level of 1milliwatt is all that is required. The T-Match bars may be adjusted with power
applied and the point of best match can be found quickly, easily and more accurately than that
with an amateur transmitter and wattmeter connected. Generally, good watt meters can
reliably indicate SWR down to about 1.2:1. A high directivity bridge or coupler can increase
accuracy, but 1.2:1 is more than adequate for any installation.
The aperture of this antenna is large enough, so that you must elevate the antenna a
minimum of about 8 feet or 2.5 m above the ground. Point the antenna so that there are no
"reflectors" or obstructions for 100 feet directly in front of the beam. A better method would be
to point the antenna straight up toward the sky. Support the antenna on a wooden or metal
pole or tube, and tie or guy the antenna boom with very light string or line. Now the driven
element will be at arm level, and ground effects are removed. Most locations are pretty clear
straight overhead as well!
Install a short length of coax (1/2 wave is ideal... The antenna impedance will repeat
each half wave from the antenna regardless of coax imperfections) between the coax
connector and your bridge or wattmeter. If you utilize your 222 MHz transmitter as an RF
source, apply power and observe the reflected power. Turn off the power and adjust the T-
Match bars equally in small increments - 1/8" or 3 mm. is a good starting point. Apply power
again and observe results. If it got better, keep going. If it degraded, change the direction of
your T-Match movement program and recheck your SWR. At some point, you will observe a
null in reflected power. When you have found it, mark the point on the driven element, then
solder the T-Match bars to the brass driven element and T-Match rods. A propane torch or
large 250 watt solder gun or iron is required here. Clean off excess flux. Non lead solders are
available for plumbing uses that oxidize less in the outdoors than conventional lead solders.
Brass, copper and tin lead solder will oxidize in the weather and over the years
performance can degrade. It is a good idea to spray your handiwork with a good grade of clear
paint sealant. As a general rule, the slower drying sprays tend to be more enduring.
Rustoleum "Clear Seal" or Krylon clear sprays are recommended. A few light coats work
better than one big one. Be sure to cover the connector before spraying.
You are now ready to install your new antenna. Be careful when you dress the coax
down the boom. Keep the coax away from any elements. Tape the cable tightly and securely
to the boom. The Boom-to Mast plate has V shaped grooves to fit mast sizes up to 2"
maximum. The small 1/4" U bolts are used to attach the boom to the mounting plate. Use the
supplied lock washers. It is a good idea to apply a small amount of white lubricant grease to
the stainless steel threads under the hex nuts to prevent galling of stainless steel. If you don't
have it, don't worry about it.

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DSEFO222‐16Rev12/13
Directive Systems Warranty Policy
All Directive Systems antennas are built with the finest materials available. We take great pride in building a
quality product that will give years of good service and performance. If there is a defect in materials or
workmanship within 90 days of purchase, Directive Systems will repair or replace, free of charge, the
defective part. DO NOT RETURN ANYTHING WITHOUT PRIOR AUTHORIZATION FROM DIRECTIVE
SYSTEMS. Please contact us either by phone or email describing the problem and we will work to resolve it.
If, after examining a new antenna you received, you are not satisfied, contact us immediately for return
authorization and refund. ANY ANTENNA THAT HAS BEEN MODIFIED WILL BE SUBJECT TO A
RESTOCKING CHARGE. IF AN ANTENNA IS SO MODIFIED AS TO MAKE IT UNUSABLE, DIRECTIVE
SYSTEMS RESERVES THE RIGHT TO REFUSE TO ACCEPT THE ANTENNA FOR RETURN.