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

[ae4pb at carolinaheli.com]

I've not heard from Marc on this but sent him an email asking if he had a
standard keyboard to try. From our earlier conversations it sounded like he
had tried at least two different keyboards already. One wireless and one
wired. I'm not doubting you Eric. Just wanting to look at this more closely.
If you've worked with Marc and the issue is resolved that's great!  Were we
able to find out if the keyboard is also the cause of the dropped
characters? Lowering the port bitrate resulted in fewer/no dropped
characters but that shouldn't be necessary (from reading and searching it
didn't sound possible to change the bitrate but apparently it is). 

 

For some reason I'm not getting emails from the reflector so I'm having to
get them on the web..

Jer

AE4PB

 

>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
<http://mailman.qth.net/mailman/listinfo/elecraft>  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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