[time-nuts] Lucent RFTFm-II-XO

Yes. The device supports a SCPI command set. The next version of Lady Heather supports it... well at least my modified Z3812A does. You probably don't need an RS422 converter. You can cobble an RS-232 connection into the RS-422 port. This usually works, but some hardware serial ports

Re: [time-nuts] Lucent RFTFm-II-XO

Hi, Regarding the Lucent box- I wanted to let everyone know that once it locked to satellites, I have a 10 MHz out. The output was a square wave with some ringing, but I built a three element low pass filter and now I have a really nice 10 MHz sine wave. Thanks to all! Last question I

[time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Pardon my lack of knowledge regarding Lady Heather, what is the x-axis scale? I assumed the text line above the plot is the various y-axis scales. This is good data. Thanks On Tuesday, 13 September 2016, Mark Sims > wrote: >

[time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Hi bob, thank you for the polite response regarding rise time, indeed I would fully agree. The rise time I was referring to was the DAC efc value in the plot mark had previously attached. He just included a second plot as well. It would appear the tbolt is doing something else aggressively before

Re: [time-nuts] Jim Miller simple GPSDO

Lars: Thank you very much, your explanation was very helpful. I unfortunately don't have a background in electronics other than at a hobbyist level, and really should just lurk in the back as many of the topics discussed are way above me, but I am learning . So forgive this obvious and perhaps

[time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Okee dokeee... here it is. Not much difference. The initial step is smaller, but it still spikes. After that things are pretty much the same. After it cool down, I'm doing another run with the initial voltage set to the peak of the spike. One slight difference was with the new

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Hi The rise time of the edge is not a good measure of the accuracy of the timing It simply is a way to look at how fast your gate can ramp a signal. If you do a long term comparison of the frequency vs time and the time error vs time you will see that a tight (small) damping keeps the time

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

Hi A more significant issue with the output of the TBolt for direct microwave multiplication is the spurs on the output. When multiplied up to > 1 GHz, these are going to be a major issue. There are a lot of conventional techniques for taking care of this. If you have not already employed

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Bob, that is an excellent proof by contradiction. The reason I asked is on the plot Mark shared that first rising edge is pretty sharp for a system with a 500 s time constant. On Tuesday, 13 September 2016, Bob Camp wrote: > Hi > > The pps sync is done by resetting the counter

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

On 9/13/16 2:35 PM, Andy ZL3AG wrote: That sounds like fun! Do they have a mailing list they hang out on? yes.. amateur-dsn https://groups.yahoo.com/neo/groups/amateur-DSN/info https://eyes.nasa.gov/dsn/dsn.html On 14/09/2016, at 5:04 AM, Mike Baker wrote: Hello, Time-Nutters--

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Hi The pps sync is done by resetting the counter that generates the PPS. At a 1 ppm frequency offset, it could take 500,000 seconds to steer it in with the OCXO. It unlikely people would wait for over a week for the PPS to line up …. Bob > On Sep 13, 2016, at 5:58 PM, Scott Stobbe

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

Just shipped out three new systems for $DAY_JOB to Goldstone, Madrid and Canberra. Love it when work and time nuts intersect. > On Sep 13, 2016, at 17:35, Andy ZL3AG wrote: > > > That sounds like fun! > > Do they have a mailing list they hang out on? > >

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Interesting discussion about startup. At startup the phase error of the synthesized PPS is +- 0.5 s. Is this coarsely set to the nearest ocxo cycle once gps time is established (would make sense to do it this way), or is the half second recovered steering the ocxo? On Tuesday, 13 September 2016,

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

That sounds like fun! Do they have a mailing list they hang out on? https://eyes.nasa.gov/dsn/dsn.html On 14/09/2016, at 5:04 AM, Mike Baker wrote: > Hello, Time-Nutters-- > > Full disclosure-- I am a complete newbie at understanding the > intricacies of generating a really stable, low

Re: [time-nuts] Clean 10 MHz ref

On 9/13/2016 12:42 PM, Nick Wagner wrote: Hi to time nuts.. This source has been mentioned before. I purchased a unit several months after seeing it recommended. It is made by Leo Bodnar Electronics in England. It is The simplest way to get a very clean 10 MHz sq wave. I have only observed the

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Can anybody say more about the integrator term in the Tbolt? In the Arduino GPSDO I have, I use 1/TC/TC/damping and use damping = 2. I see Nick Sayer do the same but use damping 1.75. Simulations I have done in Excel seems to indicate that a damping in my sense of about 3 could be better to

Re: [time-nuts] Jim Miller simple GPSDO

As I have understood it the change of VCXO gain is the reason that R2-C2 can be omitted. With the VCXO with a large span the damping is needed otherwise it will oscillate. The XOR phase detector has a range of 50us with 10kHz in. The VCXO has maybe a span of 30ppm (us/s) and with R1-C1 time

[time-nuts] Clean 10 MHz ref

Hi to time nuts.. This source has been mentioned before. I purchased a unit several months after seeing it recommended. It is made by Leo Bodnar Electronics in England. It is The simplest way to get a very clean 10 MHz sq wave. I have only observed the 10 MHz on a scope .. have no other reference

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

On Tue, September 13, 2016 2:24 pm, taylor david wrote: > Briefly, Mike, there's an easy to use unit here, which takes a puck GPS > antenna and can run off USB +5V: > > http://www.leobodnar.com/shop/index.php?main_page=product_info_id=234 Mike already mentioned he has a Thunderbolt. That

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Mark wrote: I just ran a tbolt (which has been off for a couple of months) and logged the state for a couple of hours... and then remembered something about the initial DAC value setting that I had figured out long ago... it has little to nothing to do with oscillator disciplining.The

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

On 9/13/16 10:04 AM, Mike Baker wrote: Hello, Time-Nutters-- Full disclosure-- I am a complete newbie at understanding the intricacies of generating a really stable, low phase noise, accurate frequency reference for microwave reception up around the 8 GHz DSN (Deep Space Network) band. I have

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

> Hello, Time-Nutters-- > > Full disclosure-- I am a complete newbie at understanding the > intricacies of generating a really stable, low phase noise, accurate > frequency reference for microwave reception up around the 8 GHz > DSN (Deep Space Network) band. I have been following the back >

[time-nuts] Need 10 MHz for DSN space-probe hunting

Hello, Time-Nutters-- Full disclosure-- I am a complete newbie at understanding the intricacies of generating a really stable, low phase noise, accurate frequency reference for microwave reception up around the 8 GHz DSN (Deep Space Network) band. I have been following the back and forth