[WT-support] Win Test sound card dvk ??

[alex]

THANKS MUCH FOR YOUR INFO--yOU MAY KNOW ME AS V47KP/V48M.  I AM SETTING 
THINGS UP HERE IN FL WITH A DELL LATITUDE C840 AND AN ICOM 781  & K3 SO THAT 
IT WILL BE TESTED (HOPEFULLY WORKING!!) BEFORE I GO TO V4 AGAIN.  THANKS 
MUCH FER YOUR INFO WILL KEEP YOU POSTED.  ALEX
----- Original Message ----- 
From: "KL7RA" <kl7ra at ptialaska.net>
To: <support at win-test.com>; <zephd at indy.rr.com>
Sent: Wednesday, March 31, 2010 2:05 AM
Subject: Re: [WT-support] Win Test sound card dvk ??


> >The Capacitor should NOT be used with Electret Microphones (like the Heil 
> >HC7 element)
>>since these require s DX Bias Voltage for proper operation
>
> None of the eight PC's here put DC on the soundcard mic and the Heil "IC" 
> headsets
> no longer work using the Win-Test DVK option unless I bypass the soundcard 
> by a
> relay.
>
> The Heil HC-4/5 elements do not work for VOX directly connected to the 
> IC-781
> radios but when used with the Win-Test soundcard DVK the Mic elements now 
> have
> enough amplification that they work fine.
>
> The isolation transformer doesn't do anything useful for me but is good 
> engineering
> practice so I installed them.  The RadioShack part number is 273-1374 
> Audio isolation
> transformer, 1:1 turns ratio. They usually have to order them. $4. I could 
> not find any
> at Dayton last year.
>
> My PC's do not have DC to block but I also installed the blocking caps, 
> RadioShack
> part number 272-1434 1.u tantalum  Plus side towards the soundcard.
>
> RadioShack sells the 1/8" phone jacks for the soundcard, part number 
> 274-286 or you
> can just buy them ready made and cut off one end.
>
> You can build this simple DVK interface box in an evening.
>
> You still should use PTT when using DVK so I have Win-test key my PTT line 
> that is
> normally used for CW and I also have a footswitch in parallel for the ops 
> that don't
> like/use VOX.
>
> The interface boxes that have a relay to bypass the mic from the 
> soundboard adds
> more parts plus DC input and it is shown in the Win-test Manual as well. I 
> added
> yet another toggle switch to use the mic to record instead of unplugging 
> anything.
> I also added a dual color LED to indicate where the Mic was going. The box 
> starts
> to get crowded as you add "features" like PTT relay, etc. which I did.
>
> Finally not all soundcards work for DVK regardless of what driver you 
> install. We
> also had the 15 meter position cause RFI to the 20 meter position DVK. I 
> used some
> chokes on the long six foot lines to stop it. I think keeping the audio 
> lines short would
> be a good idea if you can.
>
> 73 Rich KL7RA
>
>
>
>
>
>
>
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