Installation and Operating Instructions
Although this product is intended for "self" installation into your headset, such installations requires reasonable skill in the use of soldering tool and a minimal understanding of electronics.
In the event purchaser has doubts about his/her ability to perform a proper installation, purchaser is advised to send this unit and the headset to ANR Headsets, for a professional installation. In this way, we can ensure that your new ANR system will last for years to come. In addition, your warranty will be automatically extended for one year.
Boom microphone is fixed" after installation. After the modules are installed into your headset, your boom microphone should thereafter remain on the same side. This is due to the design of our unit which locates the ANR microphone in the front end of the cavity, immediately surrounding the ear.
If you wish to change you boom microphone location from one side to the other, you should remove and swap the modules to the other side. Either way, the module marked "L" should be on the left, and the one marked "R" should be on the right. Failure to wear the headset with the ANR microphone correctly oriented may result in feedback (squealing) from the ANR system.
1.? Fine tip soldering iron (low watt)
4.?Small screwdriver set
3.? Power drill with 1/8", 3/16" and 1/4" bits
5.?Damp sponge - to clean solder tip
5.? Small to medium size wire cutters
Power Cable (1) - 60 Inch, two conductor, red = 9v (+), black = ground (-).
Set ANR Modules (1) - Marked "R" and "L". Each module contains and ANR speaker, audio speaker, microphone, and circuit board.
Crossover Cable (1) - A four conductor cable, 33" length.
Package Of Assorted Installation Materials (1) - Included 10" solder; (3) wires, 28 gage, (red, green, and black); (8-10) pieces of heat-shrink tubing; (8-10) tie-wraps; 1" of isocryl adhesive; (2) aramid fabric pads (white Oval); (1) rubber grommet.
Remove the earseals from each earcup and place them out of the way to avoid burning them with a hot soldering iron. The earseals stretch around the earcup flange and are easy to remove.
NOTE: It is mandatory that you use "gel" type earseals. The original earseals (dry or liquid filled) are not as airtight as gel seals, and in addition do not dampen sound and vibration as effectively. The result is that the ANR units will greatly under perform (20-50%) and will be more likely to malfunction.
The only earseals compatible with the ANR modules are the David Clark gel ear seals, the AvComm gel ear seals or the FlightCom gel-flo ear seals. We stock the AvComm earseal ($25).
Inside each earcup, surrounding the speaker, you will find two or three pieces of foam packing. Use tweezers to remove the top piece of foam (usually donut shaped).
After removing the foam, you will see two screws which hold each speaker in place. Remove the two screws. The speakers can now be lifted from the earcups. Disconnect the two speaker wires from the speaker.
Leave in place the deepest piece of foam insulation. The donut shaped piece should be cut in half and tucked under the edge of each earcup, after you have finished the wiring job described in the following steps.
Insert a module into each earcup to insure that a fit can be made. Generally, any make of headset which is similar to the David Clark "H-10 series" will accept the ANR module.
Some headsets have special installation prodecures. These include:
FlightCom model 4DX and 5DX have unusual method for wiring the volume control, requiring supplemental instructions. The model 5DX also has 1 circuit board in the LEFT earcup which can cause difficulty (depth problem). See the supplemental instructions included for those who specified this model.
SoftCom C-60 has PTT (push to talk) switch in right earcup, must be disabled, but the push button switch may be left in place.
David Clark H-10-13.4 has earcup which is shallower than most. Therefore the left side requires extra attention to tucking wires away when finally closing the LEFT earcup.
Using a pen or marker, mark a point at the base of the left earcup to drill a 1/4 inch hole to permit the power cable to enter the left earcup.
Dont drill the hole at the very bottom of the earcup, because the wall thickness here can reach almost inch, which is too thick for the grommet we provide. Instead, place the hole about 1/2 inch up from the base, similar to the location of the grommet for the cable going to the boom microphone.
Check inside the earcup to be sure you are not going to hit an obstruction (i.e., the post where original speaker was mounted). There is usually no need to remove the last (deepest) piece of insulation from the earcup before drilling this hole. If you find it necessary, you should take care not to bend the terminals on the volume control.
The David Clark terminals (later models only) are small and brittle (brass) and will break with very little flexing and are difficult to repair w/o replacing the entire volume control. Other makes with their steel terminals have had no problems. Breakage usually occurs when attempting to re-insert the foam piece under the wiring.
Note: If you have a later model David Clark, we recommend that you leave the last piece of foam in place and treat wiring carefully.
Drill a 1/8" pilot hole, then enlarge to 3/16", and then 1/4". Carefully de-burr the edges of the hole with a small knife. Remove all debris. Install the rubber grommet, making sure it is fully seated inside the earcup.
Feed the power cable through the grommet and place a tie wrap on the cable about 3" inches from the upper end of the cable to prevent it from being pulled out. Remove the outer insulation (black casing) above the tie wrap. Pull down on the cable to seat the tie-wrap, pulling slowly so you dont unseat the grommet.
After the power cable is installed and seated, attach it to the main cable using the black 3" tie-wraps. Place a tie-wrap every 10 inches along the cables. Trim off the excess tie-wrap length. The two cables will quickly tangle if they are not bundled together.
The crossover cable is the cable that runs from your left earcup to your right earcup, and the original cable probably has only two leads. If so, it must be replaced with a cable having at least three leads.
Some headsets have a crossover cable containing two wires and a bare shield. By using the shield as a 3rd conductor, you may re-use this original crossover cable.
With this method, be sure and disconnect the crossover cable shield from the remainder of the shield system (notice the shields for the microphone, audio, and crossover cable all connect together in the LEFT earcup).
To use the shield as a third conductor, solder a 3" length of the 28ga wire to each end of the shield. Carefully twist both ends of the crossover shield and tin both ends (melt solder into). You may designate the shield as either 9v(+) or audio(+) or ground(-) (use the appropriate color wire provided to keep things straight). You will now have sufficient wire lengths to continue the installation.
IMPORTANT: Avoid loose strands of wire. Double check to see there are no bare strands exposed. Cover the splice with shrink wrap and heat gently.
If your headset does not have a shielded crossover cable, you must install the new cable provided. Using wire cutters, remove your existing cable and replace with the new crossover cable. The new cable should easily slide through and replace the old cable.
Some headsets require a four lead crossover cable. These include any headset which has a single volume control located in the right earcup (e.g. all Sigtronics models, Dave Clark H10-60). Figure "C" shows the layout for this arrangement.
After the original speakers have been removed and the new power and crossover cables have been installed, there will be eight (8) bare wires in the LEFT earcup and four (4) bare wires in the RIGHT earcup that need to be identified. It is very important to realize that colors cannot be relied on to identify the existing audio (+) and ground wires.
Refer to the wiring diagrams below:
Mono Headset with single volume control on left side.
Mono Headset with two volume controls.
Mono Headset with single volume control on right side.
Stereo Headset with two volume controls,
Mono Headset with no volume controls.
The key wires to be identified are audio (+) and ground (-). In stereo headsets, audio (+) will have two wires (RIGHT and LEFT). In mono headsets the audio (+) usually passes through the volume control as per figure "A".
The ground (-) wire will usually be black or white. Identity can easily be confirmed with a continuity tester applied to the audio plug and the unknown wire. The audio plug is the larger of the two plugs (audio and microphone). The tip of the audio plug is audio (+).
The base of the audio plug is audio(-). If there is a band of metal between the tip and base of the plug then you have a stereo headset. In stereo headsets the tip of the plug is usually audio (+) LEFT , and the 2nd band of metal is audio (+) RIGHT with the base of the plug being ground(-).
Dont assume the identity of wires in your headset based on color without confirming identity. Use the above method, along with the descriptions provided below, to identify the original audio (+) and audio (-) wires. Then organize the wires so they may be soldered into a "harness" in step X.
In The Left Earcup:
1. 9v+ (red)
2. 9v(-) (black)
Leads # 1 and 2 are from the new power cable installed in Left earcup.
3. Audio(+) (green)
This lead is the original audio(+) and can be identified as it usually goes directly to the volume control.
4. Ground(-) (black)
This lead is the original audio(-) and must merge with 9v(-) to form common ground. See "two grounds merge" in wiring diagram.
6. Audio (+)(green)
Leads 5-7 carry audio, power, and ground to the right side, respectively.
8. Optional (white )
Lead 8 is only used for Mono Headsets with two volume controls.
Note: Leads 5-8 are from the left end of the new crossover cable installed previously.
In The Right Earcup (All four leads entering the right earcup are from right end of crossover cable.)
1. 9v+ (red)
2. Ground(-) (black)
3. Audio (+) (green)
Leads 1-3 will be attached to the ANR Modules.
4. Optional (white )
Lead 4 is only used for Mono Headsets with two volume controls.
All of the splicing takes place in the left earcup. In the right earcup the soldering only involves attaching the three leads of the crossover cable to the p.c. board. Review the color sketch.
The red 9v (+) wire should be spliced into two red wires, per the color diagram. One will then attach to the crossover cable (use red), will pass over the headband and attach directly to the right p.c. board. The other red wire will attach directly to the left p.c. board. Don t attach any wires directly to the printed circuit boards until the wiring harness is complete.
The black 9v(-) wire and the black ground(-) wire must be spliced together in order to create a common ground. As the 9v(-) and ground(-) wires merge into one they form a common ground wire which should be divided (spliced) into two leads, one going to each module. Use black wire. Wait until the wiring harness is complete before making the final attachment to the printed circuit boards.
The original audio cable enters the left earcup. It carries at least four conductors:
* Note: Do NOT disturb the microphone circuit. Do not splice or tie in to the microphone circuit in any manner.
In all David Clark headsets, the audio (+) lead is the wire that passes through the volume control, thereafter spliced into two leads to form RIGHT audio (+) and LEFT audio (+) leads.
One audio (+) lead connects through the crossover cable to the RIGHT module and the other connects directly to the LEFT module.
In each earcup there should now be three exposed leads, ready to solder to the modules. Tin the ends of all six wires and trim them very short. This will maximize strength at this point by causing the wires insulation to run all the way to the board.
Study the color drawing and see that the red, green, and black wires attach to the printed circuit boards consistently. The printed circuit boards are not as delicate as they appear, but you should never splice wires so that two wires attach together at one point on the printed circuit board ("ganging up"). This could result in the circuit "trace" separating from the board itself.
After the modules have been attached, tuck away all wiring and insulation. Take extra time to insure that wires are tucked out of the way so far as possible. The donut shaped piece of insulation should be cut in one place to allow it to be tucked under the edge of the earcup. Drop the modules into the earcups. If they fit well (no more than 1/32" gap between flanges), divide the isocryl adhesive into four small pieces (BB size) and place two between the flange of each earcup/module.
Two (2) white oval pieces of fabric are provided with each set. This material is intended to keep dirt and debris out of the speaker elements and to acoustically dampen the ANR modules. One should be placed inside each ANR module, covering the speaker grill holes and the microphones.
IMPORTANT: Use of the fabric pads is mandatory. Failure to use these may result in feedback (squealing). If the pads are lost or become soiled, call for a free set of replacements,
Each module is labeled RIGHT or L. Next to this is a small electret microphone housed in a grommet. Your headset must be always be worn with these two microphones located in the forward part of each cavity surrounding the ear. They must remain in this position. This results in the position of the "boom-microphone" being fixed (right or left).
These instructions assume your boom microphone is worn on the left. If your boom microphone is worn on the right, you should install the right module in the earcup with the boom microphone.
Prolonged use (three hours or more) under extremely cold conditions (under 20 degrees f) can result in moisture condensation inside the headset causing temporary malfunction. Allow unit to warm and dry before resuming use.
In cold conditions (below 32 f) remove the headset from the aircraft after each flight. If headset becomes cold soaked it can be more subject to moisture condensation. Otherwise, summertime cabin temperatures will not damage or degrade the unit.
Test the active noise system on the ramp prior to taxiing out. If there is any indication of a malfunction the power should be turned off and the headset used conventionally.
Life of a high quality 9V battery should be approximately 20-25 hours. To guard against accidentally leaving power on, unplug power cable from battery case.
Cheaper 9v batteries will not provide a stable power source, causing malfunctions. Dura-Cell , Energizer, or Ray-O-Vac alkaline batteries are required.
When battery power is depleted the ANR system will turn off as though the power switch was turned off. Headset audio will continue to operate.
A continuity tester may be required to trace a malfunction.
A technician is generally available at Headsets, Inc., Monday through Friday from 10:00 A.M. to 5:00 P.M. (Central Time) at (806) 358-6336.