[time-nuts] I am a nut

I just got an HP 8920B service monitor to replace what I had before. It has the High Stability oscillator option. After running the self tests, I was doing a quick check of the internal reference. With my frequency counter locked to a GPSDO, I see that the 8920B reference is 0.2 Hz high. OMG! I'd

Re: [time-nuts] HP 10544A Repair

On 3/1/2016 4:13 AM, Bob Camp wrote: Is it worth getting it super close? Probably not without a temperature test setup. Bob Right. It is entirely possible that if you did a temperature test in an environmental chamber, you would find that you could get a better tempco by adjusting oven

Re: [time-nuts] Inside a CTS 1960017 OCXO

Bob, I was referring to the bulk of the conversations on this device where people were finding 60 Hz related artifacts. Greg >On Date: Mon, 29 Feb 2016 21:11:19 -0500 >From: Bob Camp wrote: > >Hi > >On some parts the spur shows up in the 40 to 80 Hz range. >That pretty much rules out the line

Re: [time-nuts] Inside a CTS 1960017 OCXO

Hi The spectrum plots and scope plots do not look like a blocking oscillator. They look very much like an internal spur generated by something in the circuit taking off at low frequency. Bob > On Mar 1, 2016, at 10:09 AM, Alex Pummer wrote: > > sometimes high frequency

Re: [time-nuts] Next step up from basic GPS/PPS timekeeping

On 29 Feb 2016, at 10:46 am, Hal Murray wrote: > What distro are you starting with? > > I'm using Debian. Their kernel includes PPS support, both Wheezy and Jessie. I’m using Raspbian Jessie. PPS over GPIO is now recognised in the stock kernel but kernel PPS isn’t. I

Re: [time-nuts] GPS Outage

Hi Jim, On 03/01/2016 03:24 PM, jimlux wrote: On 2/29/16 10:56 PM, Magnus Danielson wrote: On 02/29/2016 11:31 AM, Martin Burnicki wrote: Hal, Hal Murray wrote: martin.burni...@burnicki.net said: Strange that at least 3 independant firmware trees/development teams should chose the same

Re: [time-nuts] GPS Outage

On 2/29/16 10:56 PM, Magnus Danielson wrote: On 02/29/2016 11:31 AM, Martin Burnicki wrote: Hal, Hal Murray wrote: martin.burni...@burnicki.net said: Strange that at least 3 independant firmware trees/development teams should chose the same magic wk860. I don't find it strange. If the

Re: [time-nuts] Effect of the Antenna Delay in setting in Z380!A

Hi Dave... Group delay really applies to any device, and mathematically is the rate of change of phase vs. frequency. It is usually of interest for bandpass devices, but no reason it can't be used for a piece of coax. The word 'group' comes from the idea of being interested in the delay over a

Re: [time-nuts] Inside a CTS 1960017 OCXO

sometimes high frequency oscillators could get in certain mode of operation the "blocking oscillation" see here: https://en.wikipedia.org/wiki/Blocking_oscillator, also it could happen, that the high frequency oscillation does not stops entirely, just undergoes an amplitude fluctuation, that

Re: [time-nuts] WWVB format change in 2012

As Tom mentioned I am familiar with the chips. But the bottom line is there are no chips either old style or new around anymore from what I have seen. If you can find the consumer atomic clocks that are pretty rare these days you can get the AM clock receiver from those. The new chips (Literally

Re: [time-nuts] WWVB format change in 2012

Hi > On Mar 1, 2016, at 2:44 AM, Sanjeev Gupta wrote: > > On Sun, Feb 28, 2016 at 3:09 PM, Sanjeev Gupta wrote: > >> Are there commercially (or widely-used) receivers for professional use >> which listen to the WWVB signal? > > > Folks, I am trying to

Re: [time-nuts] HP 10544A Repair

Hi As you do the tweaks, the frequency changes should go from parts in 10^8 to 10^9 to 10^10 per turn. A lot depends on the pot setup and the crystal in terms of how high it starts. The flip side to that is your counter and local reference standard need to be able to measure at least parts in

Re: [time-nuts] GPS Outage

Hi Take a look at math libraries and things like printf libraries. Each time somebody writes one, there are a group of bugs that come up again and again. Yes, you would *think* each group would come up with creative *new* errors … not so much. There are always obvious assumptions that turn

Re: [time-nuts] WWVB format change in 2012

gha...@gmail.com said: > Is there *any* commercial gear available for WWVB at all, today? Price is > not an issue, just a public product page will do. I don't know of any gear that is currently available in the US. A few years ago, you used to be able to get a small board and ferrite

Re: [time-nuts] Effect of the Antenna Delay in setting in Z380!A

On 2/29/2016 11:36 PM, Andy wrote: Dave wrote: For those of who might care I would assume that actually taking the coax and measuring the delay at 1.5GHZ would be better than relying on the manufactures published specs for velocity factor. I was going to set up and measure the delay with a

Re: [time-nuts] WWVB format change in 2012

Sanjeev Gupta wrote: > Folks, I am trying to trace down xtendwave. They seem to have released a > Everset IC, and then renamed themselves to Everset in 2013 or 2014. Contact Paul Swed or me off-list about this. > Is there *any* commercial gear available for WWVB at all, today? Price is > not

Re: [time-nuts] WWVB format change in 2012

On Tue, Mar 01, 2016 at 03:44:01PM +0800, Sanjeev Gupta wrote: > Folks, I am trying to trace down xtendwave. They seem to have released a > Everset IC, and then renamed themselves to Everset in 2013 or 2014. It's not an IC, exactly, it's a bare product intended for integration into

Re: [time-nuts] WWVB format change in 2012

On Sun, Feb 28, 2016 at 3:09 PM, Sanjeev Gupta wrote: > Are there commercially (or widely-used) receivers for professional use > which listen to the WWVB signal? Folks, I am trying to trace down xtendwave. They seem to have released a Everset IC, and then renamed themselves