[UK-CONTEST] DUMP PSK use AMTOR

[Robert Chipperfield]

On 26/04/2011 22:42, Steve Knowles wrote:
> BTW, If anyone has bothered to read this far and is having trouble 
> decoding,
> try the 'Signalink USB' external soundcard interface available from ML&S.
> Works brilliantly with MMTTY, Digipan and MIXW, even with Vista!!!  You do
> need to adjust the signal levels correctly - but you get physical controls
> on the box to do it!
And a similar couple of hints, for those not using interfaces with built 
in audio interfaces:

1) If you're using a laptop, the built-in soundcard's input is almost 
certainly very poor. However, even the very cheap ~£2.50 USB audio 
modules that can be found on eBay are usually much superior, and 
entirely suitable. Combining one of these with a homebrew interface for 
isolation works well, and is substantially cheaper than a MicroHam or 
similar if you're experimenting for the first time. I've not yet done a 
side-by-side comparison of performance, but it would be interesting to try!

For those who enjoy construction, Gavin, M1BXF has combined his version 
of the above with another USB-RS232 adaptor in a single box to give CIV 
control; it's quite a nice project: <http://bit.ly/huiLCc>. Total cost 
~£25, I think.

2) If you're using a sound card, ensure that any driver-type DSP is 
turned off: this is variously labelled in different models, but noise 
reduction, echo cancellation, or anything that claimed to improve the 
sound is almost certainly unwanted when using the sound card for 
datamodes! This has reared its head on a number of machines I've seen 
where people were struggling to get successful decodes on DSSTV, with no 
initially obvious cause.

Cheers,
Rob, M0VFC