[Elecraft] High Speed CW issue with dropped characters/delay QRQ CW

[Eric Swartz - WA6HHQ, Elecraft]

It turns out the delay in this case is due to the particular keyboard in use as 
it has a sleep mode and wakes up slowly.

73,

Eric
/elecraft.com/

On 8/6/2015 10:58 AM, ae4pb at carolinaheli.com wrote:
> Re: High Speed CW issue with dropped characters/delay at high speeds with
> K3/P3 (Jerry Moore)
>
> Some thoughts and conjecture:
> Dropped Characters:
> At the default port speed of 38400 any errors in transmission could possibly
> result in dropped data rather than a resend depending on error
> handling..etc.. I've suggested to Marc to re-seat all physical connections
> in the signal path. Lowering the port speed resulted in no dropped
> characters. I don't have the gear to actually look at this but it could be
> caused by something as simple as a bad cable, bent cable..etc.. serial data
> is pretty simple but doesn't take much to trip it at high data rates. That's
> why there's usually some error detection/correction going on with some
> applications.
>
> Delay:
> My thoughts on this are that the P3 is probably polling the radio for status
> and the K3 interrupts the TX data stream to send status,
> frequency..etc...The P3 buffers the sending data until the polling cycle
> completes and goes back to sending.
>
> Without a lot more information and gear all of my ramblings are little more
> that guesses. The Delay could perhaps be affected by prioritizing the
> traffic, knowing how long a polling cycle takes, and maybe splitting the
> polling cycle in to smaller, more often sent, bits, rather than a chunk
> stream. Of course this only currently affects communications where a
> keyboard is sending high speed characters/CW to the P3 to be sent via the
> K3. The port speed should support those rates easily but HOW the
> conversation takes place may need to be tweaked a bit.
>
> Fixes for the Dropped Characters may be as easy to fix with a new cable or a
> shorter one.
>
> Just thinking out loud here. I enjoy helping solve technical issues.
>
> Jer / AE4PB
>
>
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