I think this is the last post I'll be doing on this radio. Which for some of you I'm sure is the best part of this post.
Things did not fit together the way I thought they should. Then there was that wonky channel display problem, which turned out to be a broken trace with a floating solder pad. Which meant moving or reterminating that wire. And since I was going to have to tear stuff apart...
Built a second board, this time I copied the VCO buffer amp circuit and moved a few other components around to accommodate it. (So now I'll call that little amplifier the VFO buffer.) Completely pulled the old PLL board and carefully moved wires from the old VFO board to the new one, then added a wire to replace the out of lock detector output that I had hotwired on the old PLL board.
Fired it up and it failed immediately.
Which, as you can imagine, was not the result I was hoping for.
Checked voltages, output from the +5V regulator was low. Touched the regulator, painfully hot. OK, must be a short somewhere. Started checking, no shorts. Plugged Arduino into the PC, board lit right up. Hooked frequency counter to the output of the VFO buffer and got the 19.whatever MHz I was expecting.
Which I found to be a bit odd considering it didn't work at all a few minutes before.
Took radio back to bench to recreate the problem, and it started working. So whatever was shorted was unshorted when I moved stuff around. Which tells me I need to insulate the entire board since I don't know which part was shorted.
But the channel display problem seems to be fixed.
