I'm a member of a lot of Yahoo Radio "Groups", one of the more fervent being the FT-817 group. If you have questions, it's a good place to get answers (search the message base before asking though), especially when it comes to the type of portable antennas that are being used, along with associated tuners and their "Pros & Cons".
-It wasn't long ago that someone started a "WISH" thread - something they'd like to see on the next generation of 817's. There were many additions to the original wish, but I didn't recall seeing something that I'd like to see, and could possibly be done by either Yaesu or a 3rd party manufacturer. My wish: a deluxe external microphone, similar to the MH-29 speaker/mic (which is why I used my picture of the MH-29 to reference what I wanted).
The microphone would have a display on it which would indicate frequency, signal strength, mode, voltage, and whatever internal features were activated (in my example I just have the noise-blanker on-screen). The up/down buttons on top of the mike would change frequency in either direction, and you'd have a double row of buttons below the display, each having their own function with 2 programmable buttons. The "AMP" button would activate or deactivate the microphone amplifier (a circuit similar to the One Big Punch), while the Dx/Bx button would allow the operator to choose between two different internal microphone elements (imagine an HC-5/4 combo). This would let the portable wanderer have his trusty FT-817 slung from a shoulder strap or secured on backpack, and be able to talk and walk without having to actually fumble around with the transceiver. Yeah, I know - it's pipe dream, however, it's MY pipe dream....