Diamond Antenna HF6CL Instructions

Amateur Radio Communication Antenna
50MHz 1/2 wave Radialless Center Loading Mobile Antenna

（50-54MHz can be operated）

HF6CL

Fold over whip element structure

Operation Instructions

To use the antenna properly, read these instructions
thoroughly before using it. Keep this manual carefully
at hand for later use.

HF6CL is for amateur use. Please transmit on the amateur
bands.

<<Warning>>

To avoid inviting accidents, please follow the following
notices.

①Nuts and screws can be loosened by vibration during

driving. Be sure to check those fastening devices from
time to time and refasten if necessary.

②Strong impact can cause to break the antenna and may

invited accidents by falling the element. It is
recommended to drive away from those obstacles such
as branches.

③Strong vibrations caused by diesel engines may damage

the antenna. It is recommended to install the antenna at
the location where has least vibrations as possible.

④Touching the antenna during transmission may cause to

electrify. Be sure to confirm to see if there in no one
around the antenna if transmission is taking place while
the car is parked.

⑤Don’t drive a car with the antenna tilted. Driving the car

with the antenna tilted may cause serious human
accident.

⑥To install the antenna, be sure to take those things such

as local traffic regulations, and physical length of the car
in account, and especially it has to be installed the
location where is not easily reachable by people.

⑦Adjust the antenna thoroughly on operating frequency

before operation. Using unadjusted antenna my
damage transceiver.

⑧If the thunder seems to rumbling the vicinity, do not touch

the antenna and coaxial cable to avoid electrocuted by
lightning.

⑨Select strong enough place to install the antenna to avoid

damaging the car body falling the antenna.

cause to

・Installation location

Since this antenna is designed to install on car body only,
VSWR of the antenna may not be lowered when it is
installed on the place where has different grounding
condition such as on balcony railings.

・Parts number

The unit is consisted of the antenna following parts.

Upper element (M67001)

Set Screw (M4x4) (M67005)

Loading coil (M67002)

Set Screw (M4x4) (M67005)

・Description

①Center loading type that is high performance is employed

in the HF6CL (length: 2.2m 1/2wave radialless mobile
antenna)

②It is easy to adjust the frequency by changing the upper

element. 50-54MHz can be operated.

③Fold over whip element structure eliminates troublesome

antenna detachment when the car is parked in your
garage. Whip element section of the antenna can be
tilted for desired direction by pull the element up and
incline for any direction.

Lower element (M67003)

Set Screw (M4x4) (M67005)
Fold over section

(in matching section)

Matching section (M67004)

・Assembly and Adjustment

①Set the upper element in the upper part of the loading coil

and fasten the set screw temporally.

②The element of HF6CL is adjusted to lower frequency of

amateur band at initial condition. Please check the
resonated frequency with SWR/power meter.

③Calculate the difference between the resonated

frequency and the desired frequency after confirming the
resonated frequency. Referring to the below frequency
change amount, calculate the element adjustment
length. If the frequency is lower than the desired one, cut
the element. If the frequency is higher than the desired
one, set the element at higher position.

   Frequency change amount: Approx. 75 KHz/cm

Lock nut

Loosen the lock
nut and pull the
element up.

Hold the element
and take it down
softly.

Element holder

<<Attention>>

・Do not touch the antenna during transmission to avoid

electrocuting.

・Since VSWR of an HF antenna varies depending on

installation locations, be sure to adjust at the place where
the antenna is operated in practice.

・Adjustment has to be take place at the place where is no

obstacles or power line, and where does not hinder other
cars and pedestrians.

・Due to insufficient earth capacity correct adjustment can

not be performed at the place where has vast space
under the car such as on a bridge or in the multi-level
parking lot.

・To avoid interfering other stations, adjustment has to be

performed with least RF power and shortest time as
possible.

<<Warning>>

・Setscrew for the bracket must be connected to car body

directly to have electrical interconnection. VSWR cannot
be lowered if the bracket and car body are insulated.

・VSWR may not be lowered if installing the antenna at

gutter mount or roof carrier where is away from car body.

・The place mounted with antenna bracket may get the

rusty and make the rust-proof on it.

・Be careful not to have the waters into the car from the

entrance of coaxial cable to the car.

・Wire the coaxial cable without any problem when driving.
・DonÕt install antenna, bracket and coaxial cable at the

place where is close to other wire, terminal box of the car;
otherwise, fatal accident should happen.

・Fold over whip element structure

①Loosen the lock nut and pull up when turned down.
②When setting up, raise the antenna vertically, set the

element into the element holder, and fasten with lock nut.

<<Attentions>>

・Don’t drive with the antenna turned down; otherwise, fatal

accident should happen.

・In case the antenna stretches out from the car body when

turned down, detach the antenna otherwise, fatal
accident should happen.

・When using the tiltable whip, pay attentions not to pinch

your fingers.

・VSWR

2.0

1.5

1.1

-6.5MHz  -0.4MHz     fo    +0.4MHz  +0.65MHz

・Specification

Frequency 50MHz (50-54MHz)
Max Power Rating 250W (SSB),80W (FM)
Impedance 50Ω
VSWR Less than 1.5 (at resonated frequency)
Length 2.2m
Weight 550g
Connector M-J
Type 1/2 wave radialless center loading

 Though the product being purchased is manufactured

under strict quality control, if damage is caused by
transporting, ask your dealer promptly.

 Design and specification of these products will be

changed for future improvement without advance notice.

DIAMOND ANTENNA Products are distributed by RF PARTS COMPANY

435 S. S treet San Marcos, CA 920 78 [phone]

www.diamondanten na.net