Nortel GPTM operates on 24 or 48V DC. Internally, there is a step down dc/dc
converter and 3 terminal regulators. It creates whatever it needs internally.
So it can be done. It does have quite a bit of filtering though. I have run
Oven oscillators with a regular cheap switcher. Spec says ripple is 150mV p-p.
I really didn't have problems using it as a reference clock. If I were to
multiply it to GHz range, it would likely not work.
According to spec for Wenzel Streamline, it says 15V or 12V 2.2 watts. Warm up
is 5 watts at 5 minutes.
Seem like one can simply get 12V battery of sufficient capacity and run with
that. If I were to consider a portable operation, I would rather have gell
cell batteries. It's a simple and proven technology with no catastrophic
failures. I would also have it large enough so it can be started ahead of time
and keep it running.
---------------------------------------
(Mr.) Taka Kamiya
I'm stuck in a wormhole.... Hello, worms!
On Saturday, March 9, 2019, 11:03:45 PM EST, Gerhard Hoffmann
<[email protected]> wrote:
Am 10.03.19 um 01:38 schrieb jimlux:
> Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V
> from one of those rechargeable USB power bricks. I was thinking about
> portable operation.
>
> In my case, the OCXO is something like a Wenzel streamline. I would
> think that the DC/DC probably has some noise, but maybe DC/DC to a
> higher voltage, then a good linear regulator to clean it up (or would
> the radiated noise just leak around).
>
> How quiet is the output from those USB battery things..I've used one
> to run a RTL-SDR, but that's hardly a ultimate low noise receiver.
>
That's impossible to predict. These boxes normally contain one Lithium
cell and a DC/DC converter to 5V.
Its output noise depends on the skill of the designer and the mood of
the bean counter. It is probably
not a high priority. Also, there my be "effects" from the interaction of
their switcher and your's.
And the efficiencies multiply.
BUT:
3 of these Li cells deliver 12V in ultimate quality:
<
https://www.flickr.com/photos/137684711@N07/39972841815/in/album-72157662535945536/
>
The squares on the paper are 5mm.
Noise density is better than 1nV / rtHz above 100 Hz. You definitely
need a fuse. Ishort is >> 30A.
This Panasonic type is OK. There are lots of others on the market that
claim twice the power capacity
but it's a blatant lie.
regards, Gerhard
(who thinks about using a dozen of these for portable EME tests on 432 :-) )
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