Hi, This is nearly "off-the shelf" model: https://www.axtal.com/cms/docs/doc100916.pdf The ULN version does meet the -170 dBc/Hz
Bernd -----Ursprüngliche Nachricht----- Von: Lux, Jim [mailto:[email protected]] Gesendet: Sonntag, 3. April 2022 03:14 An: [email protected] Betreff: [time-nuts] Re: Low Phase Noise 10 MHz bench signal source sought On 4/2/22 4:47 PM, Joseph Gwinn wrote: > On Sat, 02 Apr 2022 03:27:06 -0400, [email protected] > wrote: > time-nuts Digest, Vol 216, Issue 3 > >> 11. Re: Low Phase Noise70 10 MHz bench signal source sought >> (Richard (Rick) Karlquist) >> >> Date: Fri, 1 Apr 2022 19:12:07 -0700 >> From: "Richard (Rick) Karlquist" <[email protected]> >> Subject: [time-nuts] Re: Low Phase Noise70 10 MHz bench signal source >> sought >> To: Discussion of precise time and frequency measurement >> <[email protected]>, Bob kb8tq <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset=UTF-8; format=flowed >> >> He [Joe] should be looking at Wenzel Associates and NEL. >> Wenzel specs -170 dBc at 100 Hz offset. > I know of Wenzel, but they don't make bench-top lab instruments. > Rack-mount is available, but as a custom part. Wenzel will be happy (for a price) to put it in any size or shape box you want. Most people want rack mounts, but it's mostly a matter of sheet metal work and they can certainly do that. > > I did find NEL, and they do look very good. The NEL 2030A and 2030B, > which are rack-mount, are plausible. > > Both are likely expensive, with long lead times. My experience with Wenzel is that the cost isn't huge - the dominant thing will be the stuff that goes in the box (i.e. the oscillator). Essentially, you're paying for a few week's engineering and tech time to lay out and fab the thing. At 5-10k/work week, yes, you're looking at $10-20k for "the box and assembly" for a one-off. I wouldn't have them put a $200 streamline OCXO in a box <grin> If you're comfortable assembling the parts a linear supply from Acopian, a box, using frontpanelexpress.com to do the machining of the front and back panels, and the baseplate, and your oscillator. (that's what we've done at JPL on multiple occasions - although considering technician time it's probably cheaper to have Wenzel do it) Wenzel also has a sort of intermediate level where you get a plate with a bunch of parts on it to do some function, and you put *that* in a box. Depending on your frequency and performance, you *might* find a "in stock" oscillator. A 10 MHz Onyx or something like that might be basically stock. >> If he is going to measure phase noise of another source with it, >> he may need a VCOCXO to make a PLL. > Yes, voltage control is also needed, so a Rubidium can be used to > stabilize the OCXO. Or the OCXO already has that built in. Most of them have an electronic tuning input. (which can be left out as a special order). My $200 (10 years ago) speedlines have a tuning input. Of course, it's not hitting your -170 dBc requirement, but the ULN and other ones do (or come close). > > What is also needed is a very quiet source of DC power for the Rb, > OCXO, et al. None of the vendors seem to specify their PSRR (power > supply rejection ratio), and I assume that all published curves are > obtained using a battery-powered unit under test. No, that's a "call them and ask", but most have pretty good PSRR (although what are you looking for?) - the guy or gal on the phone will tell you what it is in a "not guaranteed on the data sheet" sort of way. Unless you want them to hit a spec, but you'll pay for it. https://wenzel.com/model/btuln/ mentions that they have an internal low noise regulator - it's about 5dB shy of your -170 at 100Hz requirement. I wouldn't assume battery power - but this is where a phone call helps - they'll be happy to tell you. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
