Adjustable
headstrap
Volume control
Push-To-Talk (PTT) button (yellow)
Proper Fit
When worn properly, this headset will provide significant hearing protection. If it is not worn
properly, the headset’s effectiveness in reducing harmful noise is severely compromised.
•
The length or vertical fit of the headset ear dome is adjusted by the headstrap. Adjust as
necessary to achieve a fit that ensures the headset ear dome completely covers the ear.
•
When switching between right and left dress, rotate the mic boom in an upward direction
ONLY,
as shown in the diagram below.
Rotating the mic boom in the wrong direction may damage the boom or wiring.
•
The metal headband should be rotated in an upward direction
ONLY,
as shown in the
diagram below
.
Damage to the headband cable may result from rotating the metal headband in the
wrong direction.
•
For maximum comfort, wear the headset as far back on the head as possible, while ensuring
the ear dome still completely covers the ear. If discomfort is felt in the jawbone, you are
wearing the headset too far forward.
Microphone Placement
Place the microphone in front of the mouth and
NO MORE
than 1/8" away from the lips as
shown in the diagram below. Placement of the microphone is
CRITICAL
for proper operation.
If the microphone is positioned incorrectly, you may experience a reduction in
volume and clarity of intercom and radio communication
.
Headset Volume
Turn the intercom volume down. Preset each headset volume to the highest setting (full clock-
wise). Set the intercom volume to a level above the normal comfortable listening level, but at a
level which does not cause distortion. Reset the individual headset volume for best listening level.
Intercom Communication
The UH-40 headset has a yellow Push-To-Talk (PTT) button on the ear dome. Press and
release this button to activate the microphone for intercom communication. Press and release
the button again to turn the microphone off.
Radio Transmit
The UH-40 will not transmit on the radio, it is for intercom communication
ONLY!
Mic Muffs
The headset microphone is covered with a washable, replaceable foam mic muff. This mic
muff helps prevent the “pops” and “hisses” that can occur from speaking into a microphone
that is close to the mouth.
To clean or replace the mic muff:
1. Remove the o-ring.
2. Slip the mic muff off the microphone.
3. At this time, you can decide whether to clean
or replace the mic muff.
If you clean the mic muff, use a mild detergent, rinse it out well
and let it dry completely before re-installing it on the microphone.
4. Slide the mic muff on the microphone.
5. Install the o-ring on the mic muff to secure it.
Replacement mic muffs may be ordered from your local Firecom dealer.
Replacement Parts & Accessories
Description
Part Number
300 Ohm Speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0008-00
Acoustic Foam Set, 3 pieces (internal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0027-00
Boom Assembly (flex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0015-00
Cloth Covers (a dozen pairs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0003-00
Coil Comm Cable (single plug) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0018-10
Ear Seals - Standard (pair) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0012-00
HE-150, 15 foot Headset Extension Cord . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0675-00
Headset Hanger Hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0676-00
Mic Muffs with O-Rings (dozen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0004-00
PTT - Yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108-0010-40
Volume Control, Potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151-0001-00
Volume Control, Knob . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551-0001-00
Specifications
Headsets
Sensitivity . . . . . . . . . . . . . . . . . . . . . . . 104dB re .0002 microbar @ 1000 Hz, 1 mW
Frequency Response . . . . . . . . . . . . . . . . . . . . . 100-17,000 Hz +5 dB in 6 cc coupler
Impedance . . . . . . . . . . . . . . . . . . . . . . 600 ohms nominal, 150 to 1200 ohm source
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.6 oz.
Noise Reduction Rating (NRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24dB
Microphone
DC Bias Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16 volts, not polarity sensitive
Source Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 to 2200 ohms
Output Voltage . . . . . . . . . . . . . . . . . . . . . . . 370 mV @ 114 SPL re .0002 microbar
Frequency Response . . . . . . . . . . . . . Optimized for speech clarity and noise reduction
Max. Amb. Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . 125dB SPL re .0002 microbar
Mic muff
O-ring
Mic boom
Rotate the headband
ONLY
in an upward
direction as shown.
Rotate the mic boom
ONLY
in an upward
direction as shown.
Adjustable headstrap
No more than
1/8" from lips
