[time-nuts] Re: Low Phase Noise 10 MHz bench signal source

[Joseph Gwinn]

On Fri, 08 Apr 2022 03:30:33 -0400, time-nuts-request at lists.febo.com 
wrote:
 time-nuts Digest, Vol 216, Issue 13

> 
> Message: 8
> Date: Thu, 7 Apr 2022 16:59:05 -0700
> From: ed breya <eb at telight.com>
> Subject: [time-nuts] Re: Low Phase Noise 10 MHz bench signal source
> 	sought
> To: time-nuts at lists.febo.com
> Message-ID: <624F7AC9.6040509 at telight.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> On 4/7/22 3:09 PM, Joseph Gwinn wrote:
>  >
>  > This BTULN OCXO looks very good.  While they do mention that it
>  > contains its own regulator, no numbers are given, so it's hard to
>  > know what to make of that claim.
>  >
> 
> As far as I know, every OCXO and most everything else has its own 
> internal supply and further regulation of some sort, running from the 
> crude real world sources applied. As long as the supply you give it 
> meets the specs and other characteristics, stated, it should be just 
> fine. Making the outside supply part better may or may not make the 
> thing work better, but maybe it's worth a shot.

Could well be, but the lack of a PSRR spec is crippling.
 
> 
>  >> I wouldn't assume battery power - but this is where a phone call helps -
>  >> they'll be happy to tell you.
>  > I must say that I've run into the battery-power (or *really* good lab
>  > power supply) approach, neither which is applicable in non-lab
>  > applications.  I suppose if Wenzel does the packaging, they will
>  > ensure that full OCXO performance is achieved when powered from the
>  > usual lab AC power.  The box would also shield the power wiring and
>  > frequency-control input (if any) and associated wiring from passing
>  > EMI.
> 
> 
> Relating to power supply filter capacitance multipliers from the 
> concurrent 1/f noise discussion, are you talking about this kind of deal 
> maybe?
> 
> <http://www.wenzel.com/documents/finesse.html>

It does seem to be a capacitance multiplier of some kind, but it's 
hard to tell because the circuit diagrams are rendered in black lines 
on a very dark gray background - it's basically illegible.  I've not 
found a pdf - seems to be web only.  Time to call Wenzel, it seems.

What people are using for the film capacitance to be multiplied are 
aluminium-polymer capacitors, with United Chem-com brand being 
favored for use directly across power rails.

Joe Gwinn