Directive Systems & Engineering DS 88-8 User manual

The DS 88-8 eight element high performance FM yagi has been designed to complement the capabilities of
modern FM stereo tuners and minimize any reception problems due to heavy overcrowding of stations, the norm
in most areas of the country. A good antenna, like a good tuner, can make a tremendous difference in your FM
reception.
The DS 88-8 has been computer optimized for the best possible pattern and gain characteristics from 88 to 92
MHz to help alleviate interference from stations broadcasting on the same frequency or channel from different
directions. The use of a rotator, is a must with this antenna. and will illuminate the amazing flexibility that the
DS88-8 will add to your reception capabilities.. A high gain rating provides about thirteen times (11 dBd) the
improvement over simple dipole antennas. Improved signal to noise ratio for stereo signals will result.
In short, the DS 88-8 has been designed to meet every severe FM reception problem likely to be encountered by
the discriminating listener. Other models are available to cover other band segments above 92 MHz. Models are
also available for full band coverage. Call the factory for details.
The DS 88-8 is constructed of high strength 6063-T832 aluminum tubing. All elements are thick walled
high strength construction with stainless steel hardware throughout for long life. Compare the construction with
other FM broadcast antennas on the market and you will be convinced of our commitment to value, performance
and quality.
seamless
The DS 88-8 eight element high performance FM yagi has been designed to complement the capabilities of
modern FM stereo tuners and minimize any reception problems due to heavy overcrowding of stations, the norm
in most areas of the country. A good antenna, like a good tuner, can make a tremendous difference in your FM
reception.
The DS 88-8 has been computer optimized for the best possible pattern and gain characteristics from 88 to 92
MHz to help alleviate interference from stations broadcasting on the same frequency or channel from different
directions. The use of a rotator, is a must with this antenna. and will illuminate the amazing flexibility that the
DS88-8 will add to your reception capabilities.. A high gain rating provides about thirteen times (11 dBd) the
improvement over simple dipole antennas. Improved signal to noise ratio for stereo signals will result.
In short, the DS 88-8 has been designed to meet every severe FM reception problem likely to be encountered by
the discriminating listener. Other models are available to cover other band segments above 92 MHz. Models are
also available for full band coverage. Call the factory for details.
The DS 88-8 is constructed of high strength 6063-T832 aluminum tubing. All elements are thick walled
high strength construction with stainless steel hardware throughout for long life. Compare the construction with
other FM broadcast antennas on the market and you will be convinced of our commitment to value, performance
and quality.
seamless
DS88-8 PATTERNDS88-8 PATTERN
F= 88.9 MHzF= 88.9 MHz
DS 88-8DS 88-8
FM BROADCAST BAND YAGI ANTENNAFM BROADCAST BAND YAGI ANTENNA
SPECIFICATIONS
FREQUENCY:
FORWARD GAIN:
IMPEDANCE:
BEAMWIDTH:
FRONT TO BACK RATIO:
BOOM LENGTH:
ELEMENTS:
WEIGHT:
FREQUENCY:
FORWARD GAIN:
IMPEDANCE:
BEAMWIDTH:
FRONT TO BACK RATIO:
BOOM LENGTH:
ELEMENTS:
WEIGHT:
88 -92 MHz (88-108 useable)
13.1 dBi (11.0 dBd)
75 ohms balanced feed
41 degrees
20+ dB
17.25 ft.
8
13.5 lbs (assembled) 17 lbs. Shipping wt.
88 -92 MHz (88-108 useable)
13.1 dBi (11.0 dBd)
75 ohms balanced feed
41 degrees
20+ dB
17.25 ft.
8
13.5 lbs (assembled) 17 lbs. Shipping wt.
DS88-8
-3dB 41
MAXIMUM SIGNALMAXIMUM SIGNAL
177 DIXON RD.
LEBANON, ME. 04027
TEL: [phone] FAX: [phone]
177 DIXON RD.
LEBANON, ME. 04027
TEL: [phone] FAX: [phone]
www.directivesystems.com

ASSEMBLY INSTRUCTIONS DS 88-8ASSEMBLY INSTRUCTIONS DS 88-8
1. Observe the parts list and diagrams ( fig 1 thru 4.) below, and verify that all parts required for assembly are included. The
hardware is packaged in a separate plastic bag. all elements and mounting blocks are supplied ready for assembly.
2. observe Figure 1 & 2, and identify each element. Elements are marked with black marker for proper position on the
boom. Assemble the boom as shown in FIG #1. Insert tubing to the alignment marks provided. Use 2" machine screws and
worm clamps to attach boom sections. Start assembling the elements in accordance with figure 1, and fasten the #1, and 4
thru 8 elements to the boom as shown. Use 1/4-20 U bolts and 1/4" hardware with element bracket. Start from the rear,
locate el #1 1" from the end of the boom. The two holes drilled in the boom are for elements 2 & 3. These holes should be
nearest the longest element. The remaining element locations
3. Assemble the two driven elements as shown in figure 3 and place them on the boom as well. These two elements are
connected together with the two 3/8" wide x 10 3/4" long PHASING STRAPS as shown in figure 4. Note that your lead in
wire will connect to element #3. ( toward the front )
4. Attach the boom to mast plate at the balance point of the antenna. (See FIG 2.) Attach a 75 ohm coaxial lead in cable to
the #8-32 machine screw terminals on element #3 (See Fig. 4). Prepare the cable as shown, and tape the cable to the
supporting mast to avoid movement in windy weather. Place the antenna on your support mast and tighten U-bolts to lock
antenna in position. The antenna elements should be parallel to the horizon for proper horizontal polarization. Maximum
pickup will be as shown in Fig #1, in the direction away from the coax cable attachment point.
1. Observe the parts list and diagrams ( fig 1 thru 4.) below, and verify that all parts required for assembly are included. The
hardware is packaged in a separate plastic bag. all elements and mounting blocks are supplied ready for assembly.
2. observe Figure 1 & 2, and identify each element. Elements are marked with black marker for proper position on the
boom. Assemble the boom as shown in FIG #1. Insert tubing to the alignment marks provided. Use 2" machine screws and
worm clamps to attach boom sections. Start assembling the elements in accordance with figure 1, and fasten the #1, and 4
thru 8 elements to the boom as shown. Use 1/4-20 U bolts and 1/4" hardware with element bracket. Start from the rear,
locate el #1 1" from the end of the boom. The two holes drilled in the boom are for elements 2 & 3. These holes should be
nearest the longest element. The remaining element locations
3. Assemble the two driven elements as shown in figure 3 and place them on the boom as well. These two elements are
connected together with the two 3/8" wide x 10 3/4" long PHASING STRAPS as shown in figure 4. Note that your lead in
wire will connect to element #3. ( toward the front )
4. Attach the boom to mast plate at the balance point of the antenna. (See FIG 2.) Attach a 75 ohm coaxial lead in cable to
the #8-32 machine screw terminals on element #3 (See Fig. 4). Prepare the cable as shown, and tape the cable to the
supporting mast to avoid movement in windy weather. Place the antenna on your support mast and tighten U-bolts to lock
antenna in position. The antenna elements should be parallel to the horizon for proper horizontal polarization. Maximum
pickup will be as shown in Fig #1, in the direction away from the coax cable attachment point.
DESCRIPTION
Boom, 1 3/8" x 72" ( Rear section drilled 3X)
Boom, 1 1/2" x 72" ( Mid section )
Element block ( aluminum)
Insulator block
Phasing strap, 3/8" x 10 3/4" long
Aluminum half washer
8-32 x 2" machine screw
8-32 X 1 1/2" machine screw
8-32 hex nut
#8 lock washer
#8 Solder lug
1/4-20 x 1 1/2" U-bolt
1/4" lock washer
1/4-20 Hex nut
5/16 X 2" U bolt
5/16 Hex nut
5/16 Lock washer
Boom to mast bracket 3" X 5"
Element #1 (Reflector) 1/2" OD X 66"
Element #2 (Dipole 1) 1/2" OD X 28 15/16"
Element #3 (Dipole 2) 1/2" OD X 29 1/8"
Element #4 (Director 1) 1/2" OD X 60 1/4"
Element #5 (Director 2) 1/2" OD X 58 13/16"
Element #6 (Director 3) 1/2" OD X 57 7/16"
Element #7 (Director 4) 1/2" OD X 56 9/16"
DESCRIPTION
Boom, 1 3/8" x 72" ( Rear section drilled 3X)
Boom, 1 1/2" x 72" ( Mid section )
Element block ( aluminum)
Insulator block
Phasing strap, 3/8" x 10 3/4" long
Aluminum half washer
8-32 x 2" machine screw
8-32 X 1 1/2" machine screw
8-32 hex nut
#8 lock washer
#8 Solder lug
1/4-20 x 1 1/2" U-bolt
1/4" lock washer
1/4-20 Hex nut
5/16 X 2" U bolt
5/16 Hex nut
5/16 Lock washer
Boom to mast bracket 3" X 5"
Element #1 (Reflector) 1/2" OD X 66"
Element #2 (Dipole 1) 1/2" OD X 28 15/16"
Element #3 (Dipole 2) 1/2" OD X 29 1/8"
Element #4 (Director 1) 1/2" OD X 60 1/4"
Element #5 (Director 2) 1/2" OD X 58 13/16"
Element #6 (Director 3) 1/2" OD X 57 7/16"
Element #7 (Director 4) 1/2" OD X 56 9/16"
QUANTITY
2
1
6
2
2
4
4
4
8
8
2
8
16
16
2
4
4
1
1
2
2
1
1
1
1
QUANTITY
2
1
6
2
2
4
4
4
8
8
2
8
16
16
2
4
4
1
1
2
2
1
1
1
1
PARTS LISTPARTS LIST
At this time, check all elements for tightness and position. Seal the
end of the coax cable with RTV. Locate the antenna away from metal
objects, otherwise some de-tuning and loss of performance will
result.
5. If you are using a rotator, be sure that you align the front of your
DS 88-8 to coincide with the indication on your rotator controller.
Maximum signal is shown in Figure 1. at right.
At this time, check all elements for tightness and position. Seal the
end of the coax cable with RTV. Locate the antenna away from metal
objects, otherwise some de-tuning and loss of performance will
result.
5. If you are using a rotator, be sure that you align the front of your
DS 88-8 to coincide with the indication on your rotator controller.
Maximum signal is shown in Figure 1. at right.
177 Dixon Road
Lebanon, ME. 04027
Tel [phone]
177 Dixon Road
Lebanon, ME. 04027
Tel [phone]
DS888-2
ELEMENT SPACING
element #1element #1
element #2element #2
element #4element #4
element #5element #5
element #6element #6
element #7element #7
element #8element #8
66"
28 15/16"
28 15/16"
60 1/4"60 1/4"
58 13/16"58 13/16"
57 7/16"57 7/16"
56 9/16"56 9/16"
55 13/16"55 13/16"
X2X 2
element #3element #3 29 1/8"29 1/8"
X2X 2
1"
7 9/16
7 9/16
17 5/16"17 5/16"
33 3/4"33 3/4"
67 1/8"67 1/8"
112 3/4"112 3/4"
162 15/16"162 15/16"
207"
MAX
SIGNAL
MAX
SIGNAL
ELEMENT LENGTHS
FIGURE 1.FIGURE 1.

177 Dixon Road
Lebanon, ME. 04027
Tel [phone]
177 Dixon Road
Lebanon, ME. 04027
Tel [phone]
DS 88-8 FM BROADCAST YAGIDS 88-8 FM BROADCAST YAGI
Direction sheet continued:Direction sheet continued:
The driven element section as
shown in Figure #4, is the most
critical area of the FM yagi antenna.
Observe the drawing for correct
assembly. Note that the longest
driven element (29- 1/8") is toward
the front of the antenna. Be sure to
place the phasing straps so that
they will not touch each other. Form
the straps with your hand so that a
1" (approx) space is evident where
the straps cross each other. The
antenna has been designed for a
direct 75 ohm feed impedance. The
coiled coaxial cable serves as an
effective "balun" to maintain proper
electrical performance. Do not fail to
coil the coax. Improper antenna
pattern may result! Have fun with
your new antenna!
The driven element section as
shown in Figure #4, is the most
critical area of the FM yagi antenna.
Observe the drawing for correct
assembly. Note that the longest
driven element (29- 1/8") is toward
the front of the antenna. Be sure to
place the phasing straps so that
they will not touch each other. Form
the straps with your hand so that a
1" (approx) space is evident where
the straps cross each other. The
antenna has been designed for a
direct 75 ohm feed impedance. The
coiled coaxial cable serves as an
effective "balun" to maintain proper
electrical performance. Do not fail to
coil the coax. Improper antenna
pattern may result! Have fun with
your new antenna!
ELEMENT BLOCKELEMENT BLOCK
BOOM
1/4-20 NUTS1/4-20 NUTS
5/16-18 NUTS5/16-18 NUTS
1/4" LOCK WASHER1/4" LOCK WASHER
5/16" LOCK WASHER5/16" LOCK WASHER
1/4-20 U-BOLT1/4-20 U-BOLT
ELEMENT
BOOM
TO
MAST
BRACKET
BOOM
TO
MAST
BRACKET
FIGURE 2.FIGURE 2.
Two antennas may be “stacked” for higher gain. The
vertical separation should be between 10 and 13 feet. For
stacked antennas, the feed cable must be installed
uniformly on both antennas. The “hot” lead must connect to
the same side (for instance: right side.) on both antennas.
FIGURE 3.FIGURE 3.
Solder lugSolder lug
8-32 nut & washer8-32 nut & washer
8-32 nut & washer8-32 nut & washer
8-32 nut
& washer
8-32 nut
&washer
Dipole elementDipole element
8-32 X 1 1/2" Screw8-32 X 1 1/2" Screw
8-32 X 2" Screw8-32 X 2" Screw
Insulator blockInsulator block
Half washerHalf washer
DRIVEN
ELEMENT
DETAIL
FIGURE 4.FIGURE 4.
TO RECEIVERTO RECEIVER
NOTE! PHASING STRAPS MUST CROSS
EACH OTHER.
ALLOW APPROX 1" SPACING BETWEEN STRAPS VERTICALLY.
DO NOT ALLOW STRAPS TO TOUCH EACH OTHER.
NOTE! PHASING STRAPS MUST CROSS
EACH OTHER.
ALLOW APPROX 1" SPACING BETWEEN STRAPS VERTICALLY.
DO NOT ALLOW STRAPS TO TOUCH EACH OTHER.
Coil 75 ohm coax 5 turns, 3" in
diameter. Tape to boom.
Coil 75 ohm coax 5 turns, 3" in
diameter. Tape to boom.
ELEMENT #3
TO
FRONT
TO
FRONT
29 1/8"29 1/8"
28 15/16"28 15/16"