Long time, no ham

 I haven't done anything radio related in quite a while.  The past few weeks though I have started poking at stuff again.

I started off building a QRP Labs QDX.  Build went ok, but I keep having an issue where it restarts when I transmit.  I need to debug it more.  But I didn't feel like debugging it, so instead I thought it would be fun to just build the transmit chain.  

Not working great, either.  Probably the stray wires are a bad idea.  Should have built it ugly/Manhattan.

But I got enamored with the drive chip.  I had some 74AC240's sitting around, so built one like was done here.  

I figured while I was at it I should try it out by itself, so put together a 20M lpf, and built up a little board with an SI5351, and made a little wspr transmitter using the gist here.  Pretty sure I used the same one years ago.  

Didn't expect much since I just threw an old efhw antenna around my office.  Checked with my vna and saw it was resonating low (more like 13.5MHz), and was like 2.5:1 at the wspr frequency, but tried anyway.

When I going into a dummy load, it was doing around 1.4V rms, so I think it was only doing 40mw, and with the mismatch less than that.  Still, got picked up.  WSPR is pretty much magic.

I might try to put a transformer after the `240 to lower the impedance it is seeing to get more power out, but ran out of time.  

Also somewhere in the past few weeks, I got a neat BM83 dev board.  I wanted to see if I could use iFTx working via a bluetooth connection.  Unfortunately, I didn't really fully understand the various BT profiles.  The only bidirectional one (before the latest BLE "gamer" profile) is the headset profile (HSP), which is pretty low quality.  I think it would have been enough, but the iPhone won't use that except when answering a call.  (You could access it via your own program, but that isn't what I wanted.)  I found a program that lets you route audio to it, but it doesn't use the microphone.  The only other option would be to use two bluetooth devices in A2DP mode (one source and one sink), but the iPhone apparently won't act as a A2DP sink for some reason.  ::sigh::  Wish I would have understood all of this before buying the dev board, but going through the exercises of trying to get this to work made me understand all of this a lot more than reading would have I think.