The wider bandwidth seen on OPDS may be key clicks but I have found it can be caused by a non-coherent signal, ie the 'oscillator' is not continuously running. I found this, for instance, when keying
For anyone considering building the W1VD transmitters, I would recommend using the driver circuit from the kW unit even if building a 500 watt unit. Jay W1VD WD2XNS WE2XGR/2 -- Original Message -- Fr