[Elecraft] Digital connections made easy!

[Dan Barker]

I finally got around to putting my SSB adapter to use (the microphone =
still confuses me). I wanted something simple, and the 8-pin connector =
was necessary for Audio In and PTT. So, why not for Audio out too?

I couldn't find any shielded cable in the junk box or at Radshack, so I =
put the inner conductor of some old RG-62 in the vise and pulled real =
hard. I got the jacket and the shield and nothing else. Then I shoved =
two pair from some stripped Cat-5 cable up through the Coax.

I added a 2.2K resistor, a 2222 and a diode in-line, (with generous =
chunks of shrink-fit, and put Audio Out on pin 5 of the Microphone =
connector (Not used by the MH2). Now I have a single connection to the =
rig, and three plugs on the other end of the wire; Headphone, Line-In =
and Comm (DB-9). Very neat and no feedback or RFI.

To get Audio-Out on pin 5, I soldered a 2" wire to the fifth jumper, =
offset the jumper to the numbered side of the header pins (away from the =
FUNC pin), and connected the free end to the top of R36. This AF Out =
signal level is variable by the AF Gain control, but it doesn't need any =
amplification to drive my laptop. I find a very comfortable listening =
level drives the Digipan waterfall to a "just right" shade of blue =
speckles with yellow stripes (reminds me of the 60's - Never mind). It's =
still easy to plug/unplug the FP board as long as you remember the =
jumper! Maybe I should have stolen one of the grounds on P1/J1, but the =
wire/plug seems safer to me (and no etch cutting).

The doc with Digipan says to put a 100/1 voltage divider on the =
Soundcard output to the Mic jack, but I found that wasn't necessary with =
my particular laptop/earphone connection. YMMV.

All 3 interface components fit inside some 3/8 inch shrinkfit and with =
the braid bunched up, they are shielded FB. I should have photographed =
it before I sealed up the connections, but it's pretty simple. Just bend =
the collector of the 2222 up over the top, and feed the base and emitter =
to the ends of the diode. In (from DTR) via the 2.2K and about 6 grounds =
neatly tacked nearby.

Dan / WG4S / K2 #2456