James Moritz wrote:

I found that trying to change the centre frequency caused the program to
lock up - you could enter a new frequency OK, but it then seemed to be
impossible to close the dialogue box - the only way to get out of it was to
shut down the whole program using ctrl-alt-del and the task manager.

Hi Jim,
  I have been unable to reproduce this behaviour... even if changing center
frequency while transmitting, everytime it worked ok. Of course the new
frequency is used at the next tone time, but no problems as far as the dialog
box is concerned.  You talk about Task Manager, so you must be using
either Win NT or Win 2000.  I tested Jason both with Win98 and Win 2000,
not with NT.  Could be this the culprit ?
Anybody else observed such phenomenon ?

73  Alberto  I2PHD