Here’s a question: If this kind of thing was easier to do on handhelds because of a ready-made interface that wasn’t OTT for something you may not want to do forever, would people be interested? Especially if holding a HT up to a phone is too much of a pain. I just ordered a PCB version of that circuit I’ve been using and they’ll arrive soon. I’ll have spares… Cost me £6.85 for 5 from JLCPCB.
It’s for 2-pin Kenwood jacks and you’ll need to supply cables. I cut the mic off a cheap Baofeng mic for mine and that cost me a fiver. But If I can find a cheap source of those cables then great. But also those cables look hard to make up if they don’t have the 2-pin jacks on, and I have no real kit for doing that myself.
You also need a TRRS lead (which I think means it’ll work with laptops AND Android phones/tablets?). I just bought one of those off Amazon for a fiver, which was a bit much. Total cost all in is probably £15 instead of the £30-50 quid ones (Easy Digi?) But those come in a fancy box.
There is an optocoupler for USB-to-Serial control too, but I won’t be using that so I have implemented a hard slide switch for TX as on the prototype.
People, get into making PCBs, I’m still addicted to it and I have learned so much.
Edit: on second thoughts Easy Digis are cheaper than I thought.