Re: Matched xtals #ubitx #bitx40

Jerry Gaffke
 

A wandering center frequency for the crystal filter could be compensated for by re-programming 
the BFO and the second local oscillator, both coming out of the si5351 on the uBitx.


On Mon, Jan 15, 2018 at 06:58 pm, DuWayne Schmidlkofer wrote:
The filter was developed by Lee Jones of TenTec, and patented in 1991, ande commonly as a Jones filter.  It has been used by TenTec, Elecraft and several others.
The problem most often found is that the center frequency changes slightly when the bandwidth is changed.  There was a modification to this design that corrected this in a magazine article a few years ago.  I will try to find it and post more information. 
--
DuWayne  KV4QB

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