[time-nuts] OT: xtal osc PN

[Magnus Danielson]

Frank,

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.

Cheers.
Magnus