Pocket PC in the cockpit question

[Brad Zeigler]

I've tried googling for answers, but have come up short. I am the proud new
owner of a Dell Axim X50V handheld PC that I intend to use for instructing.
In addition to keeping track of my schedule, contacts, and location via a
bluetooth GPS, I'm interested in using it as an inflight recorder.

I've found plenty of information regarding attenuated patch cables, but I
can't seem to find the appropriate connector to use with the Axim. It has a
four conductor 3.5mm audio jack that is used for both stereo headphones and
a microphone. Unfortunately, no one makes a headset that uses this
connector, nor do they make an adapter that spits the 3.5mm four conductor
plug into a 3.5mm mini stereo audio jack and a 3.5mm mono microphone jack.

Ideally, what I'd like to fashion is a two way line from the handheld that
could plug into a spare intercom headset jack combo. So the audio out from
the Handheld could be piped into the mike input on the intercom, and the
output from intercom audio (what would otherwise go to the headset) would be
be channeled (and attenuated) into the mike input of the four conductor
handheld plug.

The advantage of going both ways is that I can both record on the handheld,
and listen to the handheld (audio checklists, recording playback, reminders,
alerts, etc.)

Has anyone done this? Any advice or schematics? I'm willing to get out the
soldering iron and make something up, but I'm not sure I know which parts to
use.

Brad

[tscottme]

The 3.5 connector is a pretty standard item for cell phones. I'd go to Uber
Mart and buy one of their cellphone headsets with a similar plug. You
should be able to get one for $10 or less. My Nokia cellphone uses exactly
one of these 3.5 plugs to connect a cellphone headset. Once you have a
sacrificial cellphone headset, plug it into the Axim to confirm it works as
you hope. Then you can dissect the cellphone headset cable to sort out
which wires are for mic and which for earphone. Once you have the wires
labled it's a matter of attaching the proper plugs to the ends of the wire.
I've found the guys on the rec.electronics.basic news group to be polite and
helpful if you need to attenuate the signal.

Maybe Dell can tell you more about the mic/earphone plug, such as what
cellphone uses a similar plug. If you know what cellphone uses the same 3.5
plug you can buy an intercom/cellphone adapter which I've seen advertised in
AOPA Pilot. I think these cost approximately $100. These have the benefit
of being properly matched for cellphone and intercom, which my hack job
described above does not.

I have a Dell X3i that I use for notes and MP3 playback all night. I'd
suggest it might be better to use a dedicated digital recorder. These are
available at Uber Mart for well under $100 and provide 3 or 4 hours of
digital recording. Several times I've had the Dell lockup when
multi-tasking which causes me to lose the notes that were open at the time,
never info that was already saved.

--

Scott

[Joe Johnson]

"tscottme" > wrote in message
...

>... I'd go to Uber Mart...

LOL!

[Ray]

> The 3.5 connector is a pretty standard item for cell phones. I'd go to
Uber
> Mart and buy one of their cellphone headsets with a similar plug. You
> should be able to get one for $10 or less.

Most cellphones use 2.5mm headset plugs - so make sure to look carefully
before you buy. You might be able to get a 3.5mm 4 conductor cable from
Radio Shack. Digikey sells them for a few dollars:

http://makeashorterlink.com/?V26132F3A\

There probably are also places that sell pre-made adapters to split a 3.5mm
4 conductor cable into more standard mic/headphone jacks. Try a google
search for: 3.5mm "4 cond". You can also buy Dell's $25 headset and take it
apart for the connector.

- Ray