Hard-wiring David Clark headset station to ICOM A110 radio

[Airtac1]

I've tried some Ham Radio forums with no luck. I was hoping you all could help me.
I was hoping I could get some advice about wiring a David Clark headset station directly to an ICOM A110 transceiver radio.

Here’s the issue: I work at an airport an we use these radios, which are fixed to our tugs, to contact the control tower to get clearance to tow aircraft on the taxiways. We currently have this David Clark headset station connected to these ICOM radios through a series of adapter cables and plugs. I wasn’t around when they made this setup but it seems like we are always having issues with poor connections and interference. In addition, the outside temps range from 0°F to 120°F throughout the year. The ICOMs are mounted inside a steel electrical enclosure that is supposed to be water tight but still leaks.

I want to propose a plan to my boss to remove the radio equipment from the tugs and make some “Go Boxes” so the radios can be removed from the extreme weather conditions when not in use. At the same time, I would really like to find a way to wire the David Clark headset stations directly to the ICOMs. Basically bypassing the two audio jacks.

Sorry for the long post and lack of information. I’m trying to piece together as much as I can. I was able to access one of the non-functioning radios to see if I could figure out the wiring but am not very experienced with electronics. Also, I can’t find much info online on wiring the David Clark headset stations. I did find a note from whoever installed the radio, that listed which colored wire went to which terminal. I was hoping to get some assistance and advise from you all. Here is what I have so far. The top picture is what I think needs to happen. The photo is from one of the radios we have now. The other diagrams come from the manual. Thanks in advance.

 

[Audioguru]

No technical details or schematics for the radios, the headphones, the stations or the cables.
Should we guess about them??

 

[Airtac1]

Well, I thought the links in my post would take you to the technical details. At least the ones I was able to find. Are the links not working?

 

[davenn]

No technical details or schematics for the radios,

a full service manual in the link he supplied

Well, I thought the links in my post would take you to the technical details.

unfortunately the headset link shows no wiring info .... we need to know the individual wires in the cable from that headset control box to the radio

without that there isn't much that can be suggested, which is probably why you didn't get help on the other forum



Dave

 

[73's de Edd]

Sir Airtac1 . . . . . . . .

Key up Mission Impossible theme music . . . . . .

Your mission . . . Agent Airtac 1 . . . . . should you accept it . . . .
(Show closeup of Cinnamon . . . .)

Is to initially check out the involved Tx and Rx paths which I have marked up for you as pale GREEN for xmit
and RED as receive.

You are wanting to seek out . . . and see . . . if the party of the first party involved . . .twice removed . . . . has
involved his mod by the altering / or / tieing into of any of these lines.

OR

Did his changes merely involve . . . just plugging into the J7 ext spkr jack at the top of the page and /or the J6 ACC audio mike input pin 3 and PTT input pin 5 of that connector . . . . . at the extreme top left corner of the schema . . . . the BLUE areas ?

Now . . . . . .I'se gots to further, FULLY cheks out those there " David Clark headsets" fully hoping them not to be the rip off that some of those Dr dre ear puffs are.

Is it currently using that 40380G-05 Headset Station connected to the I- coms ?


UNITS SIMPLIFIED SCHEMATIC REFERENCE :

http://i.imgur.com/kq9rjSR.png

73s de Edd

 

[Airtac1]

Thanks for the reply, 73s de Edd. I'll try to answer the questions to the best of my limited abilities.

Right now, there is a homemade 6-conductor cable? running from the David Clark 40380G-05 Headset Station to a PJ-068 plug and a PJ-055 plug (Standard Fixed wing aviation headset plugs)
From there, the plugs are connected to the ICOM OPC-871 headset adapter. This adapter is connected to the ICOM A110 radio at the J6 junction. There isn't anything connected to the external speaker jack.

I did finally hear back from David Clark. They sent me the schematics of the Headset Station. Hopefully, it will make this a little easier

 

[73's de Edd]

Sir Airtac 1 . . . . . . .

You say . . . .
Right now, there is a homemade 6-conductor cable? running from the David Clark 40380G-05 Headset Station.

Does that mentioned cable connect into the D Clark at P1 / P3 / P4 connectors OR into terminal board TB1
with its 28 connection points.
And what are those physically being, screw terminals or solder connection points ?

Slight hiccup . . . . on the PDF , which somewhere ? in its distribution history , has then been J-PEGGED and then yet again.
With it constantly picking up digital deteris and crusting . . . it is as inane as a Xerox of a Xerox of a Xerox copy in the end result and resolution and accompanying trash.
I will be cleaning that up and magging up our portion of most interest

73’s De Edd


.

 

[Airtac1]

I'm pretty sure the cable is connected at the TB1 connection point. There was a note I found inside the electrical enclosure that said the following:

Brown - 4
Yellow - 5
Blue - 6 (Jumper from 6 to 8)
Orange - 7
Blue - 8 (Jumper from 6 to 8)
Green - 9
Shield - 10
Black - 12
Red - 14

Unfortunately, I can't access the inside of the D-Clark box so I don't know how they are connected. I assume the Black and Red wires from 12 and 14 are the power. Also, It appears that the drawing was made in '94 so it may have been Xeroxed a few too many times before they sent it to me.

 

[73's de Edd]

.

Sir Agent Airtac1 . . . . . . . . baggage collector . . . . ticket agent . . . . . and sometimes co-pilot

This now gets all units information collected together between two shematics .
Your last supplied wiring info has also been incorporated within the second schematic.

Chicken Kit Referencing . . . . . . . ( Feathers cost extra )

73s de Edd



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