Re: [time-nuts] Quartz Crystal Motional Movement

On Sat, 25 Jun 2016 18:33:28 -0700 "Tom Van Baak" wrote: > Don't forget about University of Western Australia's multi-decade gift > to the world -- whispering gallery Cryogenic Sapphire Oscillator (CSO >) -- which have Q near 1e9. Yes, but these are entirely a different

Re: [time-nuts] Quartz Crystal Motional Movement

On Sat, 25 Jun 2016 21:30:30 -0400 Bob Camp wrote: > Every paper I have ever read on the intrinsic Q of quartz makes the claim > that Q * F > is a constant ( Q goes up as frequency goes down). Yes, same here. But sofar I have not seen any theoretical proof of that. But then, I

Re: [time-nuts] Quartz Crystal Motional Movement

Hi So if we could just get that 180 mm blank line up and running, you could get some pretty good 1 MHz crystals. Of course that also involves minor issues like a 200+ mm diameter cold weld package and all the processing gear …. Bob > On Jun 26, 2016, at 6:40 AM, Bernd Neubig

Re: [time-nuts] Quartz Crystal Motional Movement

Bob Camp: >Every paper I have ever read on the intrinsic Q of quartz makes the claim that >Q * F is a constant ( Q goes up as frequency goes down). Unless blank >diameter gets in the way, this has been true for any >crystals I have ever >used. Q does change as overtone changes, but that is not

[time-nuts] Manual change pages for H-P 105B with 10811 oscillator

I just got an H-P 105B with a 10811 oscillator. It appears to work. Does anyone on the list have the manual update that covers this unit? Thanks, hld -- Howard L. Davidson hl...@att.net ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

OpenPNP has a set of drivers for each class of PNP machine. One of the drivers outputs LinuxCNC g-code, They already have other drivers for other kinds of machines, maybe 8 or 10 in total. Yes you could translate centroid files to G-code but that is exactly what openPNP does. It does a little

Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)

I'm not a fan of tweezers either. I use a sticky toothpick. Post-it note glue. Tweezers tend to make parts fly off into space. As for parts moving around, that is what vision is for, to find the part that needs to be picked up. On Sat, Jun 25, 2016 at 7:52 AM, Bob Camp wrote:

Re: [time-nuts] Quartz Crystal Motional Movement

Having dealt with crystal filter procurement for over 40 years, there are lots of mechanical issues as alluded to below. For crystals in the 5 to 10 MHz range, the edges have to be beveled so the blank is convex. Cleanliness is very important since it affects the plating of the electrodes. I

Re: [time-nuts] Impact of GPS antenna height measurments

Hi What are you using to determine the “correct” altitude of the antenna? In a lot of cases, the GPS is more correct (relative to it’s specified ellipsoid) than the reference being used. Bob > On Jun 26, 2016, at 9:02 AM, Mark Barettella via time-nuts > wrote: > > Using

Re: [time-nuts] Impact of GPS antenna height measurments

Are you sure that both you and the GPS are using the same sea level reference? The GPS is likely using WGS-84. How did you manually measure the antenna hight? Note that almost all topographic maps in the US were made long before 1984 On Sun, Jun 26, 2016 at 6:02 AM, Mark Barettella via

[time-nuts] Impact of GPS antenna height measurments

Using auto survey mode my gps antenna height is significantly off. I estimate my antenna’s actual height at about +5 m high and the gps indicates -17 m. My question is will this adversely influence the accuracy of the gpsdo output? Would there be any benefit to adjust this manually via the

Re: [time-nuts] over-determined clock solution

On Sat, 25 Jun 2016 22:00:25 -0400, time-nuts-requ...@febo.com wrote: > > Message: 3 > Date: Sat, 25 Jun 2016 10:07:30 -0400 > From: Steve > To: Discussion of precise time and frequency measurement > > Subject: [time-nuts] over-determined clock

Re: [time-nuts] Impact of GPS antenna height measurments

How long did you get your self survey time to?If you have the time, use the 171000 minutes which is just under 48 hours and that should be much more accurate. The other possibility is that you have your mask angle too low for timing all you need is a mask angle of 15 degrees or greater to

Re: [time-nuts] pick and place problems/design

Yes, I found that machine. There is work on going to get openPNP software to work on the liteplacer. So that machine will soon have all the capabilities of every other machine using openPNP. What has changed recently is that vision is so cheap and easy. You can buy a ready to use USB