[TenTec] QSK limits

[Ken Brown]

Every rig design is different. Transceivers that operate QSK can only do 
so within certain limits. I think everyone expects that there are 
limits, and nobody should be surprised about this. It would be really 
nice if the manufacturer specified the limits, and the rig lives up to 
the manufacturers specifications. Perhaps as important as the limits, or 
maybe more important for those who push the limits, is what the rig does 
when approaching or exceeding the limits of QSK performance.

Here is a list of some of the things we have read about on this 
reflector, that various QSK rigs do when pushed to their limits:

The receive capability between elements is reduced to such short time 
periods that it is really not usable except during character spaces, or 
even word spaces.

The duration of the transmitted RF code elements is uniformly truncated 
so that both the dits and dahs become "light".

The duration of the transmitted RF code elements is truncated in a 
seemingly random way, sometimes even loosing dits altogether.

For all of the above there are probably some rigs which continue to 
generate perfect sidetone, and some in which the sidetone does the same 
as the RF output, and still others in which the sidetone gets messed up 
in a different way from the RF output.

There are also many rigs which do a pretty good job of QSK, except for 
the first dit or dah being shortened.

Of course there are combinations of all of the above. My personal 
preference would be for the transmitted signal to remain as perfect as 
possible, with the receiving capability between elements having second 
priority. Having the transmitted signal adulterated in a somewhat random 
manner would be the least preferrable option. These are my preferences, 
and I would hope that most hams would have a similar preference for 
transmitted signal quality being the number one priority. I wonder if 
that is the case?

It takes a little more effort to determine that the transmitted signal 
is funny, than it does to notice that you are no longer receiving 
between elements. You can tell that the receive is dropping out with a 
causual test in the radio store show room. You might not realize the 
transmitted signal is weird until you have had the rig at home for a 
while. I wonder if this plays into the manufactures choices when the rig 
is designed?

DE N6KB