WARNING
THIS ANTENNA IS AN ELECTRICAL CONDUCTOR. CONTACT WITH POWER LINES CAN RESULT IN DEATH, OR SERIOUS INJURY.
DO NOT INSTALL THIS ANTENNA WHERE THERE IS ANY POSSIBILITY OF CONTACT WITH OR HIGH VOLTAGE ARC-OVER FROM
POWER CABLES OR SERVICE DROPS TO BUILDINGS. THE ANTENNA, SUPPORTING MAST AND/OR TOWER MUST NOT BE
CLOSE TO ANY POWER LINES DURING INSTALLATION, REMOVAL OR IN THE EVENT PART OF THE SYSTEM SHOULD ACCIDENTALLY
FALL. FOLLOW THE GUIDELINES FOR ANTENNA INSTALLATIONS RECOMMENDED BY THE U.S. CONSUMER PRODUCT SAFETY
COMMISSION AND LISTED IN THE ENCLOSED PAMPHLET.
ASL670
1
Your Cushcraft VHF/UHF antenna is designed and manufactured to give top performance and trouble free service. The antenna will perform
as specified if the instructions and suggestions are followed and care is used in assembly and installation. When checking the components
received in your antenna package, use the parts lists in each section. It is easiest to identify the various dimensions of tubing by separating
them into groups of the same diameter and length. If you are unable to locate any tube or component, check the inside of all tubing.
IMPORTANT: save the weight label from the outside of the carton. Each antenna is weighed at the factory to verify the parts count. If you
claim a missing part, you will be asked for the weight verification label.
There is a master parts list on page 2.
LOCATION
For best "line-of-sight" performance, position your ASL670 as high as possible consistent with safe installation practices. Avoid surrounding
obstructions such as trees, power lines, and other antennas--close proximity may reduce gain, alter directivity, or degrade VSWR.
Important
Warning: Never mount your antenna where humans and pets may contact it accidentally.
Protruding elements and hardware are injury
hazards, and contact with RF-energized conductors may cause injury, severe burns, or even death. Also, never mount transmitting antennas
in locations that expose humans to intense RF fields. The effects may be harmful, and the FCC now has specific guidelines for determining
safe RF exposure levels. For details, refer to FCC Part 97.13, to any current amateur radio handbook covering the topic of RF exposure, or
contact the ARRL web site at
http://www.arrl.org/news/rfsafety/.
Finally, never install antennas without assistance. Plan work carefully and
use only qualified persons to monitor your safely or help you. If you doubt your ability to complete the job safely, obtain the services of a
professional installation company.
MOUNTING
The ASL670 mounting bracket accepts mast diameters to 2.5" (6.4 cm) O.D., but your antenna may be supported safely with 1.5" (3.8 cm)
tubing. When installing multiple antennas on a single pipe, use a heavier mast with adequate strength to support the added load. Also,
maximize spacing between antennas to reduce interaction. Your ASL670 package contains hardware for either horizontal or vertical mounting.
For VHF operation, horizontal polarization is typically used for weak-signal CW, SSB, and AM, while vertical polarization is normal for FM
and Data modes. In some regions, different conventions apply, so check local standards.
SYSTEM GROUNDING
Direct grounding of the antenna, mast and tower is very important. This serves as protection from lightning strikes, static buildup and high
voltage which is present in the radio equipment connected to the antenna. A good electrical connection should be made to one or more
ground rods (or other extensive ground system) directly at the base of the tower or mast, using at least #10AWG ground wire and non-
corrosive hardware. For details and safety standards, consult the National Electrical Code. You should also use a coaxial lightning arrester.
Cushcraft offers several different models, such as LAC-1, LAC-2 and the LAC-4 series.
ASSEMBLY
Assemble your antenna carefully, following the directions and illustrations provided in Steps 1-6. When finished, verify all elements are
installed in the correct LPA alternating pattern, and confirm the tip-to-top length of each element matches those specified by the instructions.
Finally, to avoid unwanted noise or detuning after installation, verify that all hardware is tight and worm clamps are secure.
TUNING PROCEDURE
When assembled according to instructions, no further tuning of the ASL670 is required. Element spacing and length were determined by
computer model, and ham-band performance was further optimized using a HP-8753E network analyzer. Attempts to alter element lengths
will likely degrade the overall balanced performance of the antenna.
If VSWR exceeds 2:1 on any ham band, check for assembly errors,
incorrect element sequencing, loose hardware, interfering obstructions within the near-field of the antenna, incorrect feedline routing, or a
feedline fault. Feedline faults may include a short or open cable, sharp bends or kinks, and moisture or corrosion accumulation in connectors
and lines.
Because the ASL670 spans the entire VHF spectrum (50-450 MHz), select only high-quality low-loss feedline and keep cable runs as short
and direct as possible to minimize attenuation. The antenna's feedline is terminated in a low-loss female type-N connector. While N-to-UHF
(SO239) adapters are readily available at most electronic supply sources, type-N connectors are recommended for operaton above 144 MHz.