Jim said:

The QRSS modes easily meet 2 and 3; in order to meet 1, a dot
length of about 7 seconds maximum would be required. With the
best possible conditions, I guess several stations might manage
transatlantic QSOs with these dot lengths. However, it would
probably not be enough to reach the more inland parts of Canada,
or the USA and further afield.

With the existing technology, as Jim says, two way transatlantic contacts
have been shown to be possible with relatively short dot periods. The secret
is to monitor LF conditions and then choose appropriate dot periods. With
the VE1ZZ/VE1ZJ/G3LDO QSO, VE1ZZ used 3 second dots because he was using a
relatively high erp, while I allocated myself (in the first instance) 10
second dots. In the event this worked so there was no need for me to
increase the dot period.
This method of optimum dot period selection can be used to optimise the QSO
time so that it can be contained within a peak of good LF conditions. I
think we got it right because our QSO lasted around 50 minutes.
However, even with the 20w erp or so that VE1ZZ is using we had to wait for
a couple of days before we could make our reverse crossband 136/80m contact
on the 21/2. This goes to show that LF conditions are everything and that
close liaison between the operators taking part in any tests is essential.

I acknowledge that the QRSS coding is primitive but it has the advantage of
simplicity and has shown itself to be successful. It will be interesting to
see how things change now that the WOLF is at the door.


Regards,
Peter, G3LDO

<[email protected]>