Comet CA-F72GF User manual

Instruction Manual
MODEL
Thank you for purchasing our products.
For your safety :
Read this manual carefully for proper handling and operation before using.
Keep this manual in a safe place for future reference.
CA-F72GF
【Specifications】
Frequency : 440-480MHz [Tunable element]
Gain : 5.5dBi [Two 5λ/8 waves in phase]
VSWR : 1.5 or less (8MHz bandwidth after
tuning)
Impedance : 50 ohms
Connector : N-Female
Max.Power : 150W(FM)
Weight : approx. 1kg
Length : approx. 1.12m
【Features】
●High-gain : 5.5dBi base station antenna.
●1-piece heavy-duty fiberglass , durable against weather and pollution.
●Frequency can be easily adjusted following the element cutting chart.
Heavy duty, high-gain base station antenna
for 440 - 480MHz
Power
Feeding
Section Lock bolt & spring
washer
Connector
M-P (for M-J)
N-P (for N-J)
Specifications or appearance is subject to change without notice.
Note2 : For long-term use, water-proofing with glue, self-fusing tape,
and/or vinyl tape is highly recommended.
Mount
support pipe
③Fasten
Mount
support pipe
Radial
Hex. Nut
Spanner
!Precautions for using
● This antenna is only for ham radio. Do not use this for other purposes.
● Operation outside the specification might damage the antenna.
● Adjust the antenna correctly. Elevated SWR could damage the antenna.
● Never attempt to modify or fix the antenna by yourself.
● Do not touch the antenna while transmitting.
Hex.Nut M6
Spring
Washer
U-Bolt
Hex.Bolt
M6x30
Mount
Bracket
◆Mount Bracket & U-Bolt
Spring
Washer
Your mast
(φ30～62mm)
Make one or two loop,
and fix cable and mast.
Your 50Ω
coax.cable
【How To Assemble】
1. Assemble three radials. Fasten radial-lock Nuts securely with spanner etc....
2. Put two mount brackets on the mount support pipe. Pass the coax cable through the
pipe,and attach it to power feeding section. Be sure to fasten hex bolts firmly.
Then, attach support pipe onto the antenna.
3. Mount all assembled antennas on your mast.
This antenna is so long. Keep your eyes on balance of this antenna and use as strong
mast as you can, between 30 to 62mm dia.
*Make sure to use low loss coax cable.
Mount
Bracket
Copyright (C) 2020 COMET CO.,LTD. All Rights Reserved.
②Insert screw
3rd edition. May 2020. Printed in JAPAN.
Note 1 : Hybrid hexagon bolt with locking function is used for this product.
Compared to conventional hex bolts, a large tightening torque is required for
tightening work. Please tighten firmly until the end.
(Note:1)
Hex. Nut(M5)
①Insert the hexagon nut as far as it
will go into the radial thread.
Put one for each radial.
Hex. Nut
【Parts List】
1. Main antenna
2. Radial
3. Hex. Nut (M5)
4. Mount bracket
5. Mount support pipe
6. Lock bolt w/ sp.washer M6x10
7. Hex.bolt w/ sp.washer M6x30
8. U-Bolt w/sp.washer & Hex.nut
- 1
- 3
- 3
- 2
- 1
- 1
- 2
- 2
(Note:1)
This antenna requires adjusting the element length to set the tuning frequency.
Refer to the instructions on page 2 and match the lengths of L-1 and L-2 to the
lengths in the table before installing.
Note 3
●Because high UHF frequency, please use high quality coax.cable and connectors.
●Kindly provide sufficient water-proof works, on connector joint section, for long priod use.

L-1 L-2
Element Adjustment chart
Lower Element Length Upper Element Length
Hollow set screw TOP→
Tuning Section
Fig.1
Fiber Glass
Power feeding
section
Set-Screw
Connector
Slide out
Loosen
the screw
Phase shifter
Section
Tuning Section
Fig.2
How to adjust frequency
1. Loosen the set-screw at the low end of power-feeding section. (Fig.1)
2. Then, slide out the entire inside wiring assembly as shown in Fig.2
3. Please adjust the length of L-1 and L-2 according to the element adjustment chart.
4. When both elements have been trimmed, reinsert the element into the fibreglass and
tighten the set-screw.
5. Before insertion, silicone at the connector section is recommended for complete
water-proof.
351mm
322mm
303mm
217mm
206mm 198mm
L-2
L-1
2.0
1.5
1.0 fo fo+2 fo+4
fo-4 fo-2 [MHz]
VSWR Bandwidth 360
340
300
220
200
180
380
320
440 450 460 470 480
[mm]
[MHz]
Important safety information:
The following instructions and any safety instructions that came with the equipment you are installing must be followed.
●Make sure all the tools and equipment you are using are in good condition. Use non-conductive ladders and all recommended
●safety equipment. Place equipment on level ground.
●Know the phone # to the local power company before installation begins.
●Look over the installation area and be sure there are no power lines overhead or anywhere contact can be made with them.
Assume that all overhead lines are power lines.
●Always work together with an assistant. In case of emergency, this partner could save your life.
●Let falling towers or antennas fall, do not attempt to catch them.
●If anything comes in contact with a power line, leave it there and call the power company for assistance
●Foul weather days are not antenna or tower installation days.
Warning — Outdoor Installations
Contacting power lines can be deadly:
Be sure no power lines are anywhere possible contact can be made. Antennas,towers and all supporting
wires etc must be kept away. To make sure there is no possibility of contact with the tower, mast or
antenna, the horizontal distance to the electrical line should be twice the total length of the mast/antenna.
This safety measure will ensure that the mast will not contact electrical power during installation or later.
!
If a person comes in contact with electrical power and cannot move:
●Do not touch that person or you could be electrocuted
●Use a non-conductive dry board, stick or rope to push or pull the person away from contact with the electrical power.
●Once they are not contacting electrical power or you feel you cannot safely move them CALL 911, or summon
professional assistance immediately.
●If certified, begin CPR until help arrives.
Make sure all towers and masts are securely grounded and cables connected to antennas have lightning arrestors.
This will help prevent electrical and fire damage as well as human injury in case of a lightning strike, static build-up
or short-circuit within equipment connected to the antenna.
Refer to the National Electrical Code for grounding details