A funny looking "SMA" ended cable.... https://elpromatime.com/portfolio_page/time-server-nts-pico/ (Scroll down.)
Also, has anyone tried this? (An alternative to Meinberg on Windows perhaps...) https://elpromatime.com/downloads/ I'd take a look, but I don't run Windows here any more. Cheers n beers. Dave G8KBV ------------------------------------------------------------------------ On 28/06/2020 12:44, time-nuts-requ...@lists.febo.com wrote: > Message: 2 > Date: Sun, 28 Jun 2020 04:32:49 -0700 > From: Tom Van Baak <t...@leapsecond.com> > To: time-nuts@lists.febo.com > Subject: Re: [time-nuts] Vibration isolation of quartz oscillators > Message-ID: <e4f6a47c-9963-6414-6c57-8aa199acb...@leapsecond.com> > Content-Type: text/plain; charset="utf-8"; Format="flowed" > > About slabs and stability... Around the world there must be a hundred > precision time labs, including official NMI (National Metrology > Institute) labs that contribute to the calculation of UTC itself. You > run into photos of these labs and their T&F gear on the web all the time > when you search for time nutty stuff. Those of us with home labs -- even > if just a few vintage frequency standards -- can relate. > > Anyone, one of my favorite lab photos is from VSL, the Dutch Metrology > Institute. Photo attached. [1] > > Spend time time pan/zooming around the gear in the photo. The usual > suspects: hp 105 quartz; TimeTech (I think); lots of SDI > (Spectradynamics); also Truetime or Symmetricom stuff; maybe that's an > old Tracor/Fluke VLF receiver on the far right (?); and of course lots > of Stanford Research SR620 counters, the TIC still used by almost every > time lab. > > But what really caught my eye was not just the four hp 5071A in the > foreground but *how they are mounted* -- on top of massive granite blocks! > > The answer is [42]. In this case the question is how many cm wide is a > 5071A cesium clock? That means the scale of the 1600x1200 JPG is about > 1.5 mm per pixel, which implies the blocks are exactly 50x50x40 cm. > That's nearly half a ton of mass. Note the unknown mystery support > technique underneath. Either they had spare black granite blocks lying > around their office that looked really cool or they put some thought > into vibration isolation of their clocks. Still, tell me more about > inner tubes. > > I personally don't know the background of this setup. If you have VSL or > .NL connections please let us know. I remember when I first talked with > them about their lab many years ago, the UTC(VSL) BIPM stability numbers > seemed unusually good to me for "a national lab with only 4 cesium > clocks" so the granite blocks left a heavy impression on me. > > Anyway, for those of you looking for maximum quartz oscillator / > frequency standard stability and vibration isolation, maybe the granite > block isolation idea is worth looking into. I know Michael mentioned > space constraints for his BVA so this rock solid slab solution might not > help him. > > /tvb > > [1] I can't find the original vsl.nl web photo that I remember. But a > recent one like it is: > > https://elpromatime.com/wp-content/uploads/2018/10/VSL.jpg , via: > > https://elpromatime.com/portfolio_page/time-server-nts9000 , via: > > many google image searches for words including: VSL dutch metrology .nl > caesium 5071a clocks UTC BIPM > > -- Created on and sent from a Unix like PC running and using free and open source software: _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.