[Fwd: LF: Spectrogram dot length]

[Andre' Kesteloot]

Mike Dennison wrote:

> In bench tests it has been claimed that there is no advantage in
> going for a dot length exceeding 3 or 4 seconds when using QRSS
> and Spectrogram.
>
> During a QRSs QSO this weekend with DJ5BV, local interference
> came on at S9 blanketing the screen with 'snow'. DJ5BV had been
> a very clear, but inaudible signal previously and it is a tribute to this
> technique that I could complete the contact with an inaudible
> station despite S9 QRM. However it was a great struggle and relied
> largely on me knowing that there were only a few possible things
> he could have been sending. (The old 160m tricks come in useful).
>
> What is interesting is that his dashes at about 9 seconds long
> were much more readable that his dots as they stood out from the
> noise. Most of the final over was read using just the dashes!!
>
> This makes two points:
> 1) What a good idea it was to have reports using just dashes.
> 2) There does appear to be an advantage in a practical situation
> when dot lengths are increased to 10s or so.
>
> On the subject of QRSs, it may be useful to list a few abbreviations
> which are acceptable. For instance, DJ5BV did not send QRZ? to
> me, he just sent ?? which was clearly understood. A replacement
> for 73 would be useful - what about just TU (meaning 'thank you' for
> anyone who hasn't done HF CW recently)?
>
> Mike, G3XDV (IO91VT)
> http://www.dennison.demon.co.uk/activity.htm