Re: Is push pull hf amp has higher spectral purity

Brian
 

From memory, I measured the spur to be 35dB down on the 7.15MHz signal. Nobody else reported measuring it which surprised me since quite a bit was written about modding the LPF to meet fcc on harmonics.
The 12MHz xtal filter in my rig was very bad on the LF side, perhaps one xtal is slightly off frequency. I did consider building a new 12MHz filter but never got around to it. I have several home built filters at 8.86MHz but they are just a bit too big to fit in.
I decided to leave it as is and only use USB with digital.
Brian.

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