Earseals This EM-1 headset is designed to be used with the silicone gel earseals provided. Extra-thick earseals are not recommended and may cause some loss of anr strength due to the additional volume inside the earcup assembly.

Battery life A high quality 9V battery should last approximately 15-20 hours. To guard against accidentally leaving power on, unplug the power cable from the battery case when unit not in use. Use only high quality 9v batteries. We recommend Dura-Cell , Energizer, or Ray-O-Vac.

When battery voltage falls below approximately 7.5 volts the noise control system will automatically turn off. The effect is the same as manually switching the power source to the off position. The audio (radio) speakers are independent from the anr system and will continue to operate without 9 volts.

Optional power sources The EM-1 headset requires a very stable power supply. Use of non approved power supply systems may cause malfunctions, possibly damaging the circuitry and voiding the warranty.

Do not attempt to power the headset directly from your aircraft electrical system without using our panel mount power unit. The voltage spikes & background static from most aircraft are enough to damage the very sensitive integrated circuits in the headset. Our panel mount power supply unit has dual voltage regulators and is isolated with a DC/DC converter.

Boom mic location Your EM-1 headset is set up at the factory for a left side boom mic location, and we recommend you keep the boom mic on your left side. If you desire to wear the boom mic on the right side, you may do so. However, the headset will be slightly more subject to malfunction (oscillate or emit a squealing sound).

Audio input A standard aircraft radio is all that is required to supply audio to the EM-1. When power is applied, the audio (radio) volume will be amplified by about 2-3 db. Be prepared to reduce or adjust volume levels accordingly.

An audio signal is not necessary for the active noise reduction circuit to operate. Supplying 9 volts to the headset will activate the noise canceling system.

Volume controls Because the audio is slightly amplified when power is switch on, volume levels will probably be excessive unless your volume controls are reduced to about 75% of maximum. Then, to further adjust the volume, adjust the intercom volume control.

Extreme temperatures In cold conditions (below 32 f) remove the headset from the aircraft after each flight. If headset becomes cold soaked it is more subject to moisture condensation. Although summertime cabin temperatures will not damage or degrade the unit, we recommend removing the headset from the aircraft if left outside in direct sunlight. Never place the headset or battery pack above the glare shield beneath windshield where temperatures get extremely high.

Prolonged use (3+ hrs) under extremely cold conditions (under 20 degrees f) can result in moisture condensation inside the headset causing temporary malfunction. Allow unit to warm & dry before resuming use.

Pre-flight testing It is wise to test the anr system on the ramp prior to each use. Place the headset on your head and allow it to gently settle. Insert the DC plug into the battery case and activate power. Be prepared to switch power off immediately if there is any indication of a malfunction. In such case the power should remain off and the headset used conventionally.

Avoid clapping Use care when placing headset on or removing it from your head. When putting on headset do not mash the earcups onto your head. If this occurs, or if earcups are allowed to forcefully spring-back against your head or against each other, any of the 4 speaker diaphrams can be easily collapsed. See Service Difficulties: oil canning

Keep fabric inserts in place Inside each earcup you will find a black/white earpad, held in place by hook-velcro. This ear pad is intended to keep dirt & debris out of the speaker elements and to acoustically dampen the noise

Experience in the operation of the headset, particularly the active noise control system, will help you confirm that the headset is functioning properly. If a problem arises, the following outline should assist you in determining if factory service is necessary.

Difficulty: Audio/communication is operable but no noise canceling.

Remedy: Anr system probably has no power. Check to see that switch on battery case is turned to "on" position; check battery.

Difficulty: Active noise control system operates but no audio (radio) communication is heard.

Remedy: Check headset volume controls and intercom volume control.

Difficulty: Audio (radio) is heard in one ear only.

Remedy: Move the mono/stereo switch to the mono position.

Difficulty: Headset emits 'squealing' or 'whistling' sound when power turned on.

Remedy: This condition may occur if black/white earpads are not in place.

This condition also may be caused by moisture build-up in earcups. Allow headset to air dry before continuing use.

Also check to see if your headset is properly oriented (i.e.. left earcup should be on your left side and right earcup on your right side).

If the condition persists, return the headset to the factory for servicing.

Difficulty: Headset emits a low frequency 'hum' or oscillation.

Remedy: A low frequency 'hum' or oscillation is usually caused by sudden ambient pressure change such as cabin door opening, landing gear extension and rapid descents. A loose fitting headset, or a weak battery may also cause this condition. Applying light pressure to earcups will usually stop oscillation. Replace battery if strength is suspect.

If the condition persists, return the headset to the factory for servicing.

Difficulty: Headset buzzes when power is turned on, or emits a sound that is similar to an oil can being squeezed ("clink-clink") when user moves head side to side.

Remedy: This condition usually occurs when a speaker diaphram becomes partially collapsed. It is usually caused by allowing earcups to clap together when placing headset on or removing from your head.

Return headset for factory service.

A technician is generally available M-F from 10:00 A.M. to 5:00 P.M. (Central Time) at (806) 358-6336.

Refer to the limited warranty at the back of this booklet for specific warranty information. Please keep your proof of purchase. We recommend you attach your purchase receipt to this booklet and retain for future reference.