Directive Systems & Engineering DSE2455LY User manual

DSE2455LY Rev 4/21
Directive Systems & Engineering
2702 Rodgers Terrace
Haymarket, VA 20169-1628
www.directivesystems.com
703-754-3876
24cm Loop Yagi, Model DSE2455LY
SPECIFICATIONS
Frequency Range: 1.24 to1.27 GHz
Number of elements: 55
Boom Length: 180 inches
Boom diameter: 1 inch
Mast diameter: 2 inches max.
Weight: 7 ½ pounds assembled
Connector: Type N female
Gain: ≅21 dBi
3 dB Beamwidth (E Plane) : ≅14º
F/B ratio: >20 dB
Maximum Power: 550 W. average
Stacking distance: 27 inches’vertical
30 inches’horizontal
Note: All hardware is Stainless Steel unless otherwise noted.
BEFORE INSTALLING YOUR NEW ANTENNA, PLEASE BE SURE
TO READ THE ENCLOSED WARNING PAMPHLET.
ASSEMBLY INSTRUCTIONS
1) Unpack antenna and locate the three preassembled antenna sections and the hardware
package. The boom is broken between elements D21 and D22 & D42 and D43. Remove D22 &
D43 from the boom pieces and slide boom pieces together to alignment marks. Replace D22 &
D43 and retighten. (D22 is the element approximately 0.5 inch from the end of the boom section; it
will only fit together one way.) The booms are marked for your assembly.
2) Straighten any misaligned elements and tighten hardware if necessary. But do not touch
R1, DE or D1, as these have been factory set for minimum SWR.
3) Attach the boom to mast plate to the boom with the hardware provided. Install the U-bolts
so that the mast comes up directly under the boom. Note that the bracket can be installed for
either vertical or horizontal polarization. (See drawings below)

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DSE2455LY Rev 4/21
(Can be up or down) (Can be left or right)
4) Attach the feed line, and tape it to the bottom of the boom. The connector should be sealed
with electronic grade RTV or equivalent.
5) As shipped, the antenna SWR will be less than 1.5:1. Additional tweaking can be
accomplished by adjusting the distance between the driven element and R1 and D1, or by
adjusting the shape of the driven element. NOTE: Do not attempt this adjustment unless the
proper equipment and qualified personnel are available.
6) If antennas are to be stacked, see "Instructions for Stacking Loop Yagis".
Refer to photos in the next few steps for clarification on the Sub Boom:
7) Mount the boom to mast bracket (square tubing piece) to the center boom section,
using 8-32 X 2" screws, lock washers and nuts. Mount the boom to mast plate to this bracket
using 8-32 x 1 ¼” screws, lock washers and nuts. Note: There may be extra holes in the plate that
may be used for different applications.
8) There are two sub-boom brackets consisting of ½” aluminum angle and sub-boom
plates. Mount the angle brackets on the front and rear boom sections using 8-32 x 1 3/8”
screws, lock washers and nuts. Mount the sub-boom plates to these brackets using 8-32 x ½”
screws, lock washers and nuts.
9) Mount the sub-boom (3/4” thick wall aluminum square tubing) to the sub-boom brackets
and boom to mast plate using 8-32 x 1 ¼” screws, lock washers and nuts. NOTE: Do not
tighten any of this hardware until sub-boom assembly is complete.
DO NOT, UNDER ANY CIRCUMSTANCES, APPLY ANY TYPE OF SEALANT OR COATING TO THE
DRIVEN ELEMENT, T-ARMS OR CONNECTOR ASSEMBLY, OTHER THAN KRYLON®
CLEAR COAT. ANY OTHER COATING WILL ADVERSELY AFFECT THE SWR AND VOID YOUR
WARRANTY.

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DSE2455LY Rev 4/21
Boom to Mast Bracket
Boom to Mast Plate
Sub Boom
Sub Boom
Sub Boom Plate
Sub Boom
Bracket

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DSE2455LY Rev 4/21
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
the defective part, free of charge, to the original purchaser. 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.
URN.