[WriteLog] DVK Looking for a good circuit

[Marty Tippin]

At 10:02 PM 6/11/2001 , PTSMANTUA@aol.com wrote:
>Looking to build a good circuit for Field Day use. Will use a Kenwood TS440,
>and a Dell Laptop. Standard connectors, looking for a circuit, so I don't
>have to think, just build. We'll Operate 2B, and only one radio on at a time,
>but SO2R capability would be a plus for the future.

If all you want to do is interface the Writelog voice keyer to the rig, the 
absolute simplest way to do it is to just run the speaker output from the 
laptop to the phone patch input on the rig, with a simple RadioShack 1:1 
isolation transformer in the middle to eliminate any RFI back at the PC. 
The drawbacks here are that the microphone will most likely be "live" 
whenever you're transmitting from the DVK, so the operator will have to be 
quiet, and it's difficult to make new recordings in the DVK unless you've 
got an external mike attached.

Now, if you're lucky enough to be using a Heil headset, things can also be 
pretty easy. Instead of plugging the headset microphone into the Heil 
adapter cable that goes to the rig, put the microphone into the computer's 
MIC input, and take the speaker output from the computer to the Heil 
adapter cable, with a 1:1 isolation transformer and possibly a voltage 
divider (described on the Writelog web site under Support). Your audio will 
then route from the headset mike to the computer and back out to the rig. 
Recording a new item for the DVK is simple -- hit Shift-Fkey and start 
talking, then hit ESC to end the recording.


Now, before you get the soldering iron out...

You'd be well advised to run the SBrdChk.exe program (available on the 
WriteLog web site) on the computer you intend to use, to verify that the 
soundcard supports the features needed to make the DVK useful. If you get a 
score other than 7F from the SBrdChk program, you probably won't be able to 
use the laptop as your source computer for the DVK functionality.  I've 
just gone through a lot of pain in this area so sort of know what I'm 
talking about -- it prompted me to sell the Dell Insprion 4000 I bought 
just a few weeks ago, in favor of a Compaq Presario 1800T, which I've 
verified has the correct sound card support.

If the laptop has the "ESS Maestro 3i" sound system in it, it won't work. 
If it has the "ESS Maestro 2E" sound system, it *will* work. I don't know 
what other sound systems are in the Dell laptops, so you'll have to check 
it out for sure...

Good luck!

-Marty


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