[TimeWave-AEA] Best Way to Interface PK-232MBX to ICOM IC-706MKIIG?

[Doug Reed]

At 02:52 AM 8/13/2004 -0400, you wrote:
>I recently purchased a used AEA/Timewave PK-232MBX with upgrades.  What are
>your recommendations on how best to connect this TNC up to my ICOM
>IC-706MKIIG?
>3.	DATA connection.  Use a cable to connect the TNC to the 706's DATA
>socket (6-pin).

My suggestion would be to use the DATA connection. It is designed for any
kind of AFSK (audio) operation and it has become a standard data connection
across most or all brands of radios. That means you don't have to make more
cables for new radios unless you want to. 

The standard PS/2 6-pin DIN connector on IBM keyboards and mice is the same
connector with wires already attached. I've been told the cable works for
our needs and just about everyone has a junk keyboard or mouse lying
around, ready to sacrifice a cable for ham radio. 

It is a bitch to solder wires to these DIN connectors so I highly recommend
pre-wired, molded cables!! If you don't have a junk PS/2 keyboard or mouse,
asking at work or on the air or at a computer store should provide as many
samples as you'd care to haul away. A brand new (cheap) mouse should cost
under $5.

Just to check, I cut the cable off a sacrificial mouse. (It was hard to
choose a victim without even testing them, but I did...) My sample had 7
wires but no shield. Perhaps if you choose a fairly fat wire from a
keyboard you'll find one with a shield. But this indicates it might be
smart to run the cord through some ferrite beads near the radio DIN
connector end. And keep the unshielded cable short or the audio impedance
low, in the 600 ohm range, to reduce hum pickup. 

The manual for my Yaesu says the DIN connector expects max 1 volt
peak-to-peak TX audio at 10K impedance. Driving it from a 600 ohm source
would not be an issue. The RX audio is said to be 300mv peak-to-peak at 10K
impedance so connecting it to a 600 ohm input might cause reduced audio
level. You may need to experiment there.... Just connect the cable to the
TNC and see what happens. 

Good luck!

73, Doug Reed, N0NAS.