Purchasing Specifications

MH180-H Tactical Headset System Purchasing Specifications

A two-way radio communications headset using one or two bone vibrating transducers for receiving audio signals, and a waterproof/noise canceling electret microphone mounted on a 5 inch articulated boom for transmitting audio signals. The transducers are to be integrated with housings that permit them to be worn over the temporal bones of the face, directly in front of the ears, with no speaker hardware required in, on or over either ear, in order to permit completely unobstructed natural hearing of ambient auditory sounds. The transducers are to work as a closed (bone mass) vibrating system, not requiring air as a conducting medium. The transducers are tuned specifically for response to the human voice band.

To minimize user discomfort, and to eliminate the need for adjusting the transducer(s) to the user’s temporal bones, the transducers will be integrated into a sidepiece housing in such a way that the entire surface of the housing emits audio vibrations. To be compatible with helmets and helmet suspension systems, or other head gear including protective masks and eyewear, the transducer housings shall be rigidly attached to a non-corrosive stainless steel headset frame that extends horizontally around the back of the head and nape of the neck. The headset frame of the MH180-H will not exceed .076 inches in thickness; the sidepieces of the headset which position the vibrator(s) onto the face will not exceed 2.5 inches in height and 7/8 inches in width on the microphone sidepiece housing and 1 7/8 inches in height and 7/8 inches in width on the non-microphone sidepiece housing. To prevent undesirable downward movement of the headset frame, a vertical retention strap, designed to pass over the top of the wearer’s head, will be provided. The strap will be constructed of .750 wide nylon web gear material and shall be attached to the frame via stainless steel snap assemblies. The strapping system will feature hook and loop fastener material to allow for adjustment of up to 2 inches in order to lower or raise the head frame according to user requirements. Positioning of hook and loop adjustment will be configured in such a manner as to be positioned on the top of the user’s head to avoid potential conflict with helmet suspensions.

The headset will be designed in such a manner so as to allow an end user the choice of having the headset manufactured with the microphone positioned on the left or right side of the face to avoid potential cheek weld issues.

Each inner sidepiece housing will include cushions affixed to only those areas of the housing that make contact with the user’s face. The cushions will be designed to provide user comfort while providing a preferred level if hygiene. Each sidepiece cushion will feature an adhesive backing for ease of user application and removal. Replacement sidepiece cushions will be available from the manufacturer.

Transmitting is to be through an adjustable microphone featuring an articulated boom arm measuring 6.7mm in diameter and 5 inches in length. The microphone is to be noise canceling and waterproof up to and including three feet (1 meter) of water. The boom arm will feature a Velcro mounting ring at the element end of the arm, as well as a rubber ‘o’ ring, to secure the supplied windscreen over the microphone element.

For headset applications for radios featuring side tone capabilities, an alternative style of electret microphone will be made available featuring an ‘air baffle’ between the microphone element and the bone conductor sidepiece housing, preventing the mechanical coupling phenomenon associated with a traditional waterproof/noise canceling microphone when used with a bone conducting headset and side tone enables transceiver. Aside from the ‘air baffle’ feature, the alternative microphone will possess features identical to the traditional waterproof/noise canceling microphone, including; a 6.7mm diameter, 5 inch long, articulated boom arm and microphone element that is noise canceling and waterproof up to and including three feet (1 meter ) of water.

To enable intelligible communications when the wearer is using a gas mask or SCBA, a breathing apparatus adapter kit (featuring custom components specifically designed for the various makes and models of masks), which mechanically and acoustically couples the microphone to the voicemitter portion of the mask, will be available from the manufacturer.

In order to provide options flexibility for general and/or mission specific operations, the following options and accessories will be made available from the manufacturer:

1. Six different styles of body mount push-to-talk assemblies
2. Two different styles of remote finger switches
3. Three different styles of headset cable inline quick disconnect
4. A fully adjustable front/back head strap assembly
5. A remote radio volume control

Headset and associated PTT assemblies must be designed in such a manner as to allow dual comm/radio capabilities when requested, including the ability to receive two different radio transmissions simultaneously or have one radio’s transmissions take precedence over a secondary radio. PTT response must be configured in such a manner so as to allow the user to choose from dual PTT switches or a toggle enabled mechanism for use with a single PTT switch.

All metal hardware must be of stainless steel or treated to eliminate corrosion and allow use in saltwater environments.

All cables and strain reliefs must be made of a material that will remain flexible in cold temperatures and be resistant to petroleum based products and insect repellants.

ELECTRICAL:

Microphone:

(For Both Standard and ‘Air Baffle’ Models)

Noise Canceling Electret

Frequency Response: 150 Hz to 5KHz

Bias: 1.3V (1~20V)

Impedance: 3 KOhm

Current Drain: 30 uA at 1.3V (10~60 uA)

Rs: 16 KOhm Nominal

Preamp Options:

02: Two Wire Connectors

R: 2.2 KOhm

Supply Voltage: 2 V

Current Drain: 170 uA

Distortion (1% THD): 120 dB SPL

04: HIGH SPL “A” Model

Internal Rs omitted RX: 30 KOhm

Supply Voltage: 12 V

Distortion (1% THD): 145 dB SPL

Current Drain: 500 uA

Waterproof to 1 Meter of Water

Push-To-Talk:

(6 Styles Body Worn and Two Remote Switches Available)

Submersible to 1 meter: includes the “J” and “K” body worn assemblies and “WP” remote finger switch

Surface Water Applications: includes the “J”, “K”, “L”, “M”, “R” and “V-P/CCS” body worn assembles and “WR” and “WP” remote finger switches

Temperature Range: -55C to +85C

Operating Cycles: 30,000 to 100,000 depending on style of PTT

Snap Action Style

Transducers:

Operating Temperature: Meets or exceeds operating temperature of all current law enforcement and military transceivers

Input Impedance: 10 ohms to 1200 ohms as required to match transceiver output, specifically tuned to response of the human voice band

Receiver Response: 250 to 4000Hz

Mechanical:

Transducer Housings (a.k.a. sidepieces)

Specific Gravity: ASTM D 792 tested – (1.37 Value)

Tensile Strength Break (psi) ASTM D 636 tested – (26.227 Value)

Tensile Elongation Break (%) ASTM D 638 tested – ( 4 Value)

Flexural Modulus (psi) ASTM D 790 tested – (1.287,000 Value)

Notched Izod Impact ASTM D 266 tested – (3.0 Value)

Unnotched Izod Impact ASTM D 4612 tested – (22.0 Value)

Heat Deflection ASTM D tested – (424 Value)

Sidepiece Cushions/Adhesive:

WS-1 SBT Synthetic Chloroprene / Black

Butadiene Rubber – 24 to 65%

Styrene Butadiene Rubber – 15 to 20%

Nature Rubber – 10 to 15%

Testing Procedures (including adhesive): PSTC-33, ASTM-D-1000, TAPPI-T-411, M-44, Fasson TM-2