[time-nuts] OT: xtal osc PN

Magnus Danielson magnus at rubidium.dyndns.org
Sun Sep 19 14:17:47 UTC 2010


On 09/19/2010 09:35 AM, francesco messineo wrote:
> Hi
> On 9/19/10, Bob Camp<lists at 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.


More information about the time-nuts mailing list