Hi
Ok, single mixer phase noise basics:
First thing is to womp the mixer up to the point it almost smokes. Putting +7
dbm into
both ports on a “7 dbm” mixer is very normal in this case. Watching for the
fact that the
mixer likely is *not* a 50 ohm load is part of the process ( = pads might help
Hi Jim,
On 2022-06-20 17:57, Lux, Jim via time-nuts wrote:
On 6/20/22 2:39 AM, Magnus Danielson via time-nuts wrote:
So, a counter is really like an ADC for phase, with wide bandwidth
input and a sub-sampling mechanism (trigger/time-base). Through
processing frequency estimates can be provi
I found the info on how to calibrate and lots of other practical stuff in
here: https://martein.home.xs4all.nl/pa3ake/hmode/dds_pmnoise_pll.html
Erik
On Mon, Jun 20, 2022, 19:43 Erik Kaashoek wrote:
> Bob, Magnus,
> Thanks, clear. A counter is for ADEV, not for phase noise.
> I made a test setu
Bob, Magnus,
Thanks, clear. A counter is for ADEV, not for phase noise.
I made a test setup to learn how to use the mixer/PLL approach.
First using 10MHz from both outputs of a DSS (Rigol DG990) to observe
the DC shift with shifting the phase between the two signal.
Then by modulating one output
Hi
A “proper” phase noise analyzer will get you down to < -165 dbc/Hz. It also
will preserve
the frequency spectrum ( no sampling / nyquist roll over ). What you get at 132
Hz offset
is the (DSB) noise at that offset and *only* that noise.
With a counter ( as Magnus mentions ) the sampling pr
On 6/20/22 2:39 AM, Magnus Danielson via time-nuts wrote:
So, a counter is really like an ADC for phase, with wide bandwidth
input and a sub-sampling mechanism (trigger/time-base). Through
processing frequency estimates can be provided. Aliasing occurrs in
the sub-sampling. Modern counters c
Erik,
A counter actually measures a number of phase measurements. Then, as you
process that you get a frequency readout based on the difference between
them (event-count divided by time between phase measurements). Now, as
you want to do frequency read-out, you can do a handful of filtering
m
Hi
Bob, many thanks for your explanations/recommendations and links.
According your advices I will try to make PN measurement on new SA with
cross-correlation to get more clear picture of the output signals.
The next my step will be a quadrature method measurement and comparison of th
