Military headsets in civvy aircraft
 

I wish to use a military bone dome in a civvy aircraft with twin mic-tel sockets. Is this just a case of getting the appropriate splitter lead or am I going to be faced with an impedance matching problem? Seem to recall the Fireflys at JEFTS having some sort of problem with this.

It's not a simple splitter lead you want, but the lead with the 'adaptor' box fitted to it (available from transair or any of the other avionics/aviation suppliers).

I use a military Racal headset with one of these attached and, although it seemed pricey at the time, the headset works fine with this on.

CM

If You're handy with sticking wires together just replace the carbon mike with an electret type mike and then use a standard splitter. Even with the headset services type impedance adaptors (heath robinson at his best), they may not work on all western radios

We use splitters with an adapter box at JEFTS, which then work with other twin socket headsets in the P2 position no problem. If you have no joy email me and I'll try and find out more from the engineers.

Some good FAQs (Frequently asked questions) on this subject at www.headsetservices.co.uk - who can supply adapters, etc.
They are based at Shoreham.

No, I dont work for them, but had cause to buy from them recently. Seemed a friendly bunch.....

I had my DC's serviced by Headset Services at Shoreham. Phoned them on thursday, dropped the headsets off on Friday morning and they were fixed by friday PM. So on that basis, I'd recommend them.

The simplest way is to use an adapter available from Adams Aviation at Biggin Hill 01959 576129.Part No EMCC Mk II. Changing mics is not as simple as it sounds.

Military mic is moving coil low level output. The civil mic is DC fed which stops mil mic working, and has an output level 100 times greater so a matching amplifier with DC isolation is essential. The headphone impedance on Mil Headset is around 75 ohms compared to 300 ohms on civil headset, this may give unequal volume levels if headsets are mixed.