On 9/19/10, Magnus Danielson <mag...@rubidium.dyndns.org> wrote: > Frank, > > On 09/19/2010 09:35 AM, francesco messineo wrote: >> Hi >> >> On 9/19/10, Bob Camp<li...@rtty.us> wrote: >>> Hi >>> >>> Is -195 dbc/Hz floor good enough or is it overkill? >> >> I'd say this is obviously overkill, -160 dBc/Hz could be a good >> compromise. >> >>> >>> Is -155 dbc/Hz at 100 Hz offset a requirement or is -40 dbc ok? >> >> -40 dBc/Hz at 100 Hz is about useless, -150 dBc/Hz at 100 Hz is again >> a good compromise, the lower (practically) the better. > > Do you *really* need -150 dBc/Hz? That is a hard requirement! > >> It's hard to explain why to ones not familiar with weak signal >> operation between broadcasting signals, but really the noise floor >> raise a lot when you have some 5 or 6 broadcasts signals in 500 KHz of >> band (all with power levels of at least 10 dB more than the levels >> used in amateur radio, often +20 dB more) > > I would need some more fundamental understanding of the system and needs > to be able to understand how you come up with the above noise level at > 100 Hz.
as I said, if it's not possible or not practical, of course I'll take what I can get. The receiver will be limited by its phase noise and not for example by its IMD3. I think already -110 dBc/Hz at 100 Hz is better than any LO in commercial receivers (for ham radio at least). Best regards Frank _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
