D.
SQUELCH
Squelch is a receiver adjustment that determines how much RF signal is necessary
before your radio receiver will open. If squelch is wide open, you will hear all the
random atmospherics in the form of a loud, annoying, background hiss. If squelch is
set too tight and isn't sensitive enough, you will reduce the effective range of your
Earmark radios. Squelch is preset at the factory and should rarely need adjustment.
If it does require readjustment, for any reason, contact Earmark.
Ill THE MICROPHONE ASSEMBLY
Getting the most from your Boom Microphone requires using it properly.
The Boom Microphone is flexible and adjusts to accomodate any normal positioning.
To preserve the microphone's flexibility, always bend it gently and let it form its own
curve. Do not kink the boom or attempt to force it into a sharp angle. Damage may
result from abuse.
Position the microphone approximately 1/4 inch away from your lips. "Close talking"
the mic, by keeping it tight to your lips, makes using VOX easier and assures you will
always get maximum advantage from the mic's noise cancelling design. Keep the
red side of the mic toward your mouth. If the mic gets turned around, you'll lose
many of the mic's features.
The windscreen provides two advantages. First, the windscreen absorbs wind and
breathing noises so these noises aren't very loud when heard over the radio.
Second, they help keep the microphone capsule clean. Windscreens can be
removed and cleaned or replaced. Clean with ordinary soap and water; rinse
thoroughly and allow to dry before replacing. Spare windscreens are available from
Earmark.
IV CONTROLS AND OPERATION
A. ON/OFF VOLUME SWITCH
This switch turns the Headset ON and provides a continuous volume control, from
min to max. Located behind the receiver earcup, the switch is easy to find and large
enough to control with a gloved hand.
8.
BATTERY CONDITIONINDICATORLIGHT
The red light on the back of the receiver battery box is an indicator of battery
condition, the brighter the light the stronger the batteries. When the light fades to a
pale red, it is time to change the battery(s). If the light goes out completely, you have
very little operating time remaining.
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C. MODE CONTROL
The Mode Control is beneath the transmitter battery box. This switch selects the
two operating modes, "VOX ON" or "VOX OFF".
Duplex, Repeater and Repeating
Headsets
offer a selection of "Continuous Transmit (VOX OFF}" and "VOX with
PTT override (VOX ON)". In the "VOX OFF" mode everything you say is picked up
by the microphone and transmitted into your network. In other words, you are
transmitting all the time. In VOX you only transmit your voice when you speak loudly
enough to trip the VOX setting or push the PTT (Push To Talk) button switch on the
back of the cup.
Simplex and Half-Duplex Headsets
offer a selection of PTT (Push-to-Talk} or
VOX. To operate in the PTT mode, switch VOX to the off position and press the
button switch on the back of the cup. To operate in the VOX mode, switch to the
"VOX ON" position and speak loudly enough to trip the VOX setting. Remember in
Simplex you will not be able to hear anything said by another person on your
network while the PTT switch or VOX is activated. So, remember to release the PTT
switch when you have finished speaking.
V ACCESSORIES
A. HARD HAT MOUNTS
8.
If you need a hard hat, you should equip your Series 4C Headset with Earmark's
hard hat and hard hat brackets. Supplied as a package, the wide hard hat with
ratchet suspension and the spring mount headset adapters assure the best fit and
comfort. Contact Earmark for further information.
RECHARGEABLE POWER SYSTEMS
Rechargeable battery systems are available for the Series 4C Headsets (see
Section 11). Contact Earmark for further information.
C. REPLACEMENT PARTS
From time to time all devices need refreshing, especially soft parts such as headband
pads, windscreens, and earmuffs. Replacement parts are available from your local
Earmark Distributor or from Earmark. Please specify your Headset model when
ordering.
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