In reply to G4ERP:
I made myself a small adaptor a while ago using a 3.5mm plus, an RJ-45 connector, a non-locking push to make switch, a small plastic box from Maplin and about a meter of cat-5 cable.
The idea was to allow me to use a standard set of headphones + boom mic together with a PTT switch in my pocket while walking around with my hands in my pockets during winter activations.
I guess the short answer to your question is no. You suspect you’ll have have few problems with a Skype-style head-set. For added simplicity and reduced weight you could of course use the built-in VOX rather than a PTT switch. Personally I think I’d prefer to stay in control over what gets transmitted!
Don’t have the details of the circuit I used at hand, but it involves a couple of resistors and a capacitor. Most headsets I imagine use an electret mic. The headphones I use have an impedance of around 32 Ohms per channel. I have them both wired in series which doesn’t seem to cause any problems. Don’t forget to use the FT817’s SP/PH switch!
The following link may be useful
While I don’t use it much I have received nothing but favourable reports as to audio quality etc. I find headphones are less practical when you are in company since the other parties can’t hear what is going on and tend to talk over the critical bits!
If you do go the route of employing a box to house a PTT switch (and as I did 3.5mm sockets to allow an unmodified set of headphones to be used) then you could consider adding some sort of passive audio/CW filter. Of course to reduce the weight to a minimum and remove the reliability issues associated with having multiple connectors it might make sense to cut off the 3.5mm plugs and hard wire the headset.
PS If anyone can find a way to interface a bluetooth earpiece/mike to an FT817 I’d be interested to know.