[time-nuts] HP3325B as LO for a transceiver or receiver? Phase noise?

[Mark Goldberg]

On Tue, Jan 1, 2019 at 4:40 PM Jeff Blaine <KeepWalking188 at ac0c.com> wrote:

> Take a look at the plots at the bottom of this page.
>
> http://hpmemoryproject.org/technics/bench/3048/hp_sources_02.htm
>
> Note the 8642b vs the 3325B.  The '42b has much lower ultimate noise far
> out but see how decent the 3325B is in comparison.  HP really made great
> stuff back in the day!!!
>
>
Thanks for pointing out that page. My measurements of my 8642A looked
better than that far out, but are pretty similar close in. Comparing the
3325B to my measurements of TCXOs and transmit Phase noise of the TS-590,
I'm not sure it will be good enough far out to meet the 590's original
performance.

On Tue, Jan 1, 2019 at 4:29 PM Brooke Clarke <brooke at pacific.net> wrote:

> Hi Mark:
>
> It's not clear to me why pager testing requires such good phase noise.  I
> wonder if some of the amateur modes also have
> that need?
> Maybe WSPR?
> https://prc68.com/I/DRM.shtml#WSPR
>
>
The reason for good phase noise in amateur gear is if you operate in close
proximity to another strong station while trying to receive a weak one. The
phase noise will cause far out noise from the strong signal to overwhelm
the weak one. There are lots of examples on the web, explained better than
I could.

Regards,

Mark
W7MLG