[hpsdr] VHF-millimeter up/down converters?

[Helmut]

Hi Glenn,

Just my 2 cents: I think this three-mixer-design will not provide adequate
performance for severe weak signal and/or contest application on the VHF,
UHF and SHF bands. The phase noise of LOs at that these frequencies is on
principal too bad and dominates the dynamic of the whole system. A lot of
pre-amplification is necessary to meet the noise figure requirements. This
degrades the dynamic performance further.
At the present time conventional transverters are the better choice. As some
guys know I run on VHF  a  modified Mercury  and Penelope in undersampling
mode with similar performance to the HF bands (details
http://www.hamsdr.com/data/GlobalFileUploads/9636__VHF%20DDC+DUC.pdf ).
That's a nice option for the 2m band.

73, Helmut, DC6NY




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