Re: [time-nuts] Spectrum Analyzer Specifications
Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob > On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist > wrote: > > > > On 3/23/2016 3:56 PM, Bob Camp wrote: > >> and standard covered. If you want to do spurs, spend $40 and build a phase >> noise test set that will drive the sound card on your PC. >> >> Lots of choices …. >> >> Bob >> > > Any documentation on this $40 phase noise test set? > > Rick N6RK > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PTP Grandmaster Clock using Macro Sniffing
Hello, First full disclosure, I work for a PTP vendor. A master is not that difficult. The protocol is well defined and there are a few open source stacks available. More and more PHYs have time stamping built in though each manufacturer has their own method for getting time stamps out of the PHY. Time stamping also can be done in the the ethernet MAC as well with a small FPGA. this is what we do. The hard part, even for large companies, is getting a good slave servo. From an operator stand point just sync is not the goal, it is to pass traffic. The loading of a carriers network can be quite large and the networks are big, staggeringly big. China Unicom has over 1M clocks in their network. Now they have full on path support (transparent switches) and gateway clocks (node with GNSS as primary ref with PTP as backup) To see what kind of packet delay variation (PDV) slaves must cope with look at ITU G.8261 test case 12 through 17. Thees test cases try to put together to see what the worst PDV is for a 10 switch between master and slave telco network. While G.8261 is specifically for transfer of frequency it has become the defacto test suite, common phase limits for 3g would be 1.5 us, lte 5g tdd is around 400 to 500 ns. Now how good dose you slave have to be? If your slave will not see, say 80% load, or packet re-routing (floor jumps), or have to cope with more than a few small switches, a relatively simple servo with a time constant of 100 to 300 seconds will work fine and get you +- 100 ns across a number of nodes. Link On Mar 23, 2016, at 12:36 PM, Vlad wrote: > > > Hello, > > Today I woke up with an idea to search the resources about PTP Grandmaster > Clock building. > > However, its appeared, only commercial solutions is available now. Its pretty > common to see several NTP implementation using various HW (GPS is most > frequent now) > But almost no "home-brew" projects for PTP GrandMaster clocks. I would assume > its too complex or just "geek toy" which has no sense to build. > > Also, I am interesting if anybody tried Macro Sniffing (sensing and slaving > to external macrocell broadcasts) for the time synchronization. > > > -- > WBW, > > V.P. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob Any documentation on this $40 phase noise test set? Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Thanks for the explanation. I actually built something like that 30 years ago using an LT-1028 op amp, only it used an HP3582 FFT box instead of a sound card (which didn't exist at the time). Does anyone have any experience with the low frequency cutoff of sound cards? You would think 20 Hz, but maybe they go lower?? Any recommended sound cards (or USB things that work like sound cards)? Rick On 3/24/2016 4:42 AM, Bob Camp wrote: Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist wrote: On 3/23/2016 3:56 PM, Bob Camp wrote: and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of choices …. Bob Any documentation on this $40 phase noise test set? Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] EFTF 2016
Fellow time-nuts, As I fixed many of the remaining issues with my travels to York today, I got curious about what fellow time-nuts will attend. I will be there the full week and will in fact arrive to York already on friday 1 april. I have a paper to present which I hope will be interesting. There is however only so much you can tell in 15 min and 4 pages. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] eLORAN on the air dates
The Wildwood, NJ eLoran transmitter will be continuously broadcasting from 0900 (EST) on 05 April 2016 through 1500 (EST) on 20 April 2016. Wildwood will be broadcasting as 8970 Master and Secondary most of the time but occasionally may operate at other rates. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
I'd be willing to assist with board layout if someone wanted to make this into a real project (e.g., fully developed schematic). TAPR might be talked into supplying at least bare boards; we'd have to get a sense of demand before committing to a full kit or assembled unit. John On 3/24/2016 9:04 AM, jimlux wrote: More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob Any documentation on this $40 phase noise test set? Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Rick, Depending on the "card" (it's more like USB dongle now) and their choices of ADCs and DACs, you may or may not bypass the DC blocking caps. I know that people playing around with laser-shows use this trick, but it was quite some time since I look at was is available. Would be interesting to see what is available. If one has ADCs and DACs, when one could implement the loop in digital, which have the additional benefit that adjusting it can be automated. Cheers, Magnus On 03/24/2016 02:31 PM, Richard (Rick) Karlquist wrote: Thanks for the explanation. I actually built something like that 30 years ago using an LT-1028 op amp, only it used an HP3582 FFT box instead of a sound card (which didn't exist at the time). Does anyone have any experience with the low frequency cutoff of sound cards? You would think 20 Hz, but maybe they go lower?? Any recommended sound cards (or USB things that work like sound cards)? Rick On 3/24/2016 4:42 AM, Bob Camp wrote: Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist wrote: On 3/23/2016 3:56 PM, Bob Camp wrote: and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of choices …. Bob Any documentation on this $40 phase noise test set? Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Most of the USB sound cards have a capacitor coupled input. If you jumper the cap they will go down to DC. T - Original Message - From: "Richard (Rick) Karlquist" To: "Discussion of precise time and frequency measurement" Sent: Thursday, March 24, 2016 9:31 AM Subject: Re: [time-nuts] Spectrum Analyzer Specifications Thanks for the explanation. I actually built something like that 30 years ago using an LT-1028 op amp, only it used an HP3582 FFT box instead of a sound card (which didn't exist at the time). Does anyone have any experience with the low frequency cutoff of sound cards? You would think 20 Hz, but maybe they go lower?? Any recommended sound cards (or USB things that work like sound cards)? Rick On 3/24/2016 4:42 AM, Bob Camp wrote: Hi Pretty simple: Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist wrote: On 3/23/2016 3:56 PM, Bob Camp wrote: and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of choices …. Bob Any documentation on this $40 phase noise test set? Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Don't really need anyone who can order up bare boards in bulk anymore. Many of the board houses will make them on demand for single customers. They fit them into empty spaces in larger board orders. I'd love one if someone is willing to draw it up. I'll even put together a Mouser BOM that can be shared if N8UR will layout the board. :) Bob KI2L On Thu, Mar 24, 2016 at 1:31 PM, John Ackermann N8UR wrote: > I'd be willing to assist with board layout if someone wanted to make this > into a real project (e.g., fully developed schematic). TAPR might be > talked into supplying at least bare boards; we'd have to get a sense of > demand before committing to a full kit or assembled unit. > > John > > > On 3/24/2016 9:04 AM, jimlux wrote: > >> More like $40 in parts, without a board, etc. >> The RPD-1 is $20.70 >> LT1678/LT1679 is a nice low noise opamp that does rail to rail and is >> about $5 >> etc >> >> >> >> On 3/24/16 4:42 AM, Bob Camp wrote: >> >>> Hi >>> >>> Pretty simple: >>> >>> Double balanced mixer, RPD-1 is one option, there are others. >>> >>> Fairly simple L/C lowpass between the mixer and an op-amp. >>> >>> 20 db positive (non-inverting) op-amp amplifier string after the mixer >>> >>> Output of the string goes to the sound card. Use a good (dual / quad) >>> audio op amp >>> >>> Quadrature amp picks off the output of the first op amp stage, switch >>> and resistors to set gain, pot to set op point. >>> >>> >>> >>> So what you have is an old style quadrature phase noise amp and “PLL”. >>> More or less a very junior version >>> of the 3048 test box. Like any setup of this sort, you check two >>> similar oscillators. They run in quadrature and >>> you do a few “measure this with switch in position A” sort of things >>> to set things up each time. >>> >>> Nothing exotic. >>> >>> Bob >>> >>> > Any documentation on this $40 phase noise test set? Rick N6RK >>> >>> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFTF 2016
Hello MagnusI wiil be there. I will give a tutorial on piezoelectric resonator measurement on Monday afternoon. I will arrove on Sun afternoon and leave Thu afternoon. Would be great to have a Timenuts meetingBest regardsBerndDK1AGAXTAL Von meinem Samsung Galaxy Smartphone gesendet. Ursprüngliche Nachricht Von: Magnus Danielson Datum: 24.03.16 17:36 (GMT+01:00) An: Discussion of precise time and frequency measurement Cc: mag...@rubidium.se Betreff: [time-nuts] EFTF 2016 Fellow time-nuts, As I fixed many of the remaining issues with my travels to York today, I got curious about what fellow time-nuts will attend. I will be there the full week and will in fact arrive to York already on friday 1 april. I have a paper to present which I hope will be interesting. There is however only so much you can tell in 15 min and 4 pages. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Hi The board is pretty non-critical. It’s 90% audio. The biggest hassle is a power supply. You would *like* a fairly high voltage, at least if you are driving a spectrum analyzer. That may not be quite the case with a sound card. It depends a *lot* which one you are running. Something like a QA401: https://www.quantasylum.com/content/Products/QA401.aspx Would make a good target device. It’s based on the AKM 5397 So might some Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the advantage of a nice box and full USB isolation (ground loops are a pain). It also has drivers and all the OS hooks. The Janus is a bit more “DIY” with no drivers or interface (let alone isolation). The Janus is < 1/4 the price. The high voltage (+/- 18V linear regulated) supply approach makes a lot of sense with the QA401. It probably does not make as much sense with the Janus. Switching regulators of any sort are something I would strongly recommend against in a system like this that is trying to measure noise floor at audio …. The schematic changes a bit depending on what the target is. I can draw it up if there is a consensus on the target. One example: If the “sound card” is DC coupled, you can use it to indicate (and check) quadrature. If it’s an AC device, you need some sort of isolated output for another indicator. Bob > On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: > > I'd be willing to assist with board layout if someone wanted to make this > into a real project (e.g., fully developed schematic). TAPR might be talked > into supplying at least bare boards; we'd have to get a sense of demand > before committing to a full kit or assembled unit. > > John > > On 3/24/2016 9:04 AM, jimlux wrote: >> More like $40 in parts, without a board, etc. >> The RPD-1 is $20.70 >> LT1678/LT1679 is a nice low noise opamp that does rail to rail and is >> about $5 >> etc >> >> >> >> On 3/24/16 4:42 AM, Bob Camp wrote: >>> Hi >>> >>> Pretty simple: >>> >>> Double balanced mixer, RPD-1 is one option, there are others. >>> >>> Fairly simple L/C lowpass between the mixer and an op-amp. >>> >>> 20 db positive (non-inverting) op-amp amplifier string after the mixer >>> >>> Output of the string goes to the sound card. Use a good (dual / quad) >>> audio op amp >>> >>> Quadrature amp picks off the output of the first op amp stage, switch >>> and resistors to set gain, pot to set op point. >>> >>> >>> >>> So what you have is an old style quadrature phase noise amp and “PLL”. >>> More or less a very junior version >>> of the 3048 test box. Like any setup of this sort, you check two >>> similar oscillators. They run in quadrature and >>> you do a few “measure this with switch in position A” sort of things >>> to set things up each time. >>> >>> Nothing exotic. >>> >>> Bob >>> > Any documentation on this $40 phase noise test set? Rick N6RK >>> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Hi Most of mine used OP-27 and OP-37 op amps. The typical destination was a 3561 in most cases. It was nice because it had built in “normalize to 1 Hz” capability. Many sound cards will go below 20 Hz. The problem is often that the noise rises fairly quickly as you go below 10 Hz. You also get into some interesting settings issues with the normal operating system based drivers. “Twitter needs to change the audio level to send you an alert” is a gotcha. Bob > On Mar 24, 2016, at 9:31 AM, Richard (Rick) Karlquist > wrote: > > Thanks for the explanation. I actually built > something like that 30 years ago using an LT-1028 > op amp, only it used an HP3582 FFT box instead of > a sound card (which didn't exist at the time). > Does anyone have any experience with the low > frequency cutoff of sound cards? You would > think 20 Hz, but maybe they go lower?? Any > recommended sound cards (or USB things that > work like sound cards)? > > Rick > > On 3/24/2016 4:42 AM, Bob Camp wrote: >> Hi >> >> Pretty simple: >> >> Double balanced mixer, RPD-1 is one option, there are others. >> >> Fairly simple L/C lowpass between the mixer and an op-amp. >> >> 20 db positive (non-inverting) op-amp amplifier string after the mixer >> >> Output of the string goes to the sound card. Use a good (dual / quad) audio >> op amp >> >> Quadrature amp picks off the output of the first op amp stage, switch and >> resistors to set gain, pot to set op point. >> >> >> >> So what you have is an old style quadrature phase noise amp and “PLL”. More >> or less a very junior version >> of the 3048 test box. Like any setup of this sort, you check two similar >> oscillators. They run in quadrature and >> you do a few “measure this with switch in position A” sort of things to set >> things up each time. >> >> Nothing exotic. >> >> Bob >> >> >> >>> On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist >>> wrote: >>> >>> >>> >>> On 3/23/2016 3:56 PM, Bob Camp wrote: >>> and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of choices …. Bob >>> >>> Any documentation on this $40 phase noise test set? >>> >>> Rick N6RK >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Hi I’ve built maybe a dozen of these over the years. I have never used a board for any of them. They all go down on a piece of scrap copper clad and point to point / dead bug wire up. You get a good ground and leaded parts are easier to work with anyway. Bob > On Mar 24, 2016, at 9:04 AM, jimlux wrote: > > More like $40 in parts, without a board, etc. > The RPD-1 is $20.70 > LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 > etc > > > > On 3/24/16 4:42 AM, Bob Camp wrote: >> Hi >> >> Pretty simple: >> >> Double balanced mixer, RPD-1 is one option, there are others. >> >> Fairly simple L/C lowpass between the mixer and an op-amp. >> >> 20 db positive (non-inverting) op-amp amplifier string after the mixer >> >> Output of the string goes to the sound card. Use a good (dual / quad) audio >> op amp >> >> Quadrature amp picks off the output of the first op amp stage, switch and >> resistors to set gain, pot to set op point. >> >> >> >> So what you have is an old style quadrature phase noise amp and “PLL”. More >> or less a very junior version >> of the 3048 test box. Like any setup of this sort, you check two similar >> oscillators. They run in quadrature and >> you do a few “measure this with switch in position A” sort of things to set >> things up each time. >> >> Nothing exotic. >> >> Bob >> >>> >>> Any documentation on this $40 phase noise test set? >>> >>> Rick N6RK >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron 2010B
Thank you gentlemen. Chuck, Bob I am in no rush and would appreciate it very much if and when either of you have time. On Wed, Mar 23, 2016, 21:02 paul swed wrote: > Chuck if you do rescan them Diddiers site would be a great location. > Regards > Paul > WB8TSL > > On Wed, Mar 23, 2016 at 5:11 PM, Chuck Harris wrote: > > > Yes, those are copies of my manuals. I had hoped that Brooke > > would free them one day, but not so far. > > > > I plan to rescan them and release them. > > > > -Chuck Harris > > > > Dave M wrote: > > > >> There's a CDROM available from http://www.prc68.com/P/Prod.html#Austron > >> that contains > >> a manual for the 2010B, as well as several other Austron models. Don't > >> know if it's > >> just a user guide or a full Op/Svc manual. Email the seller (Brooke > >> Clark) for details. > >> > >> Cheers, > >> Dave M > >> > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Best regards, James Fournier IT Services 277 chemin du Bord du Lac Suite 8a Pointe-Claire, QC H9S 4L2 514-562-0645 ja...@jfits.ca www.jfits.ca ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
On 3/24/2016 4:54 PM, Bob Camp wrote: Would make a good target device. It’s based on the AKM 5397 So might some Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the advantage of a nice box and full USB isolation (ground loops are a pain). It also has drivers and all the OS hooks. The Janus is a bit more “DIY” with no drivers or interface (let alone isolation). The Janus is < 1/4 the price. TAPR's been trying to find a good use for the Janus boards -- it was a product used with first-generation software defined radio systems, so we'd love to repurpose it. There is room to make a deal if someone comes up with a project to use a bunch of them. John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
If the software implements acquisition of cross power spectra Then one could implement a near state of the art cross correlation PN test set based on this. With a suitable preamp the sound card could also be used for power supply and reference noise measurement. Bruce On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: > Hi > > The board is pretty non-critical. It’s 90% audio. The biggest hassle is a > power supply. You would *like* a fairly high voltage, at least if you are > driving a spectrum analyzer. That may not be quite the case with a sound > card. It depends a *lot* which one you are running. Something like a QA401: > > https://www.quantasylum.com/content/Products/QA401.aspx > > Would make a good target device. It’s based on the AKM 5397 So might some > Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the > advantage of a nice box and full USB isolation (ground loops are a pain). > It also has drivers and all the OS hooks. The Janus is a bit more “DIY” > with no drivers or interface (let alone isolation). The Janus is < 1/4 the > price. > > The high voltage (+/- 18V linear regulated) supply approach makes a lot of > sense with the QA401. It probably does not make as much sense with the > Janus. Switching regulators of any sort are something I would strongly > recommend against in a system like this that is trying to measure noise > floor at audio …. > > The schematic changes a bit depending on what the target is. I can draw it > up if there is a consensus on the target. One example: If the “sound card” > is DC coupled, you can use it to indicate (and check) quadrature. If it’s > an AC device, you need some sort of isolated output for another indicator. > > Bob > > > On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: > > > > I'd be willing to assist with board layout if someone wanted to make this > > into a real project (e.g., fully developed schematic). TAPR might be > > talked into supplying at least bare boards; we'd have to get a sense of > > demand before committing to a full kit or assembled unit. > > > > John > > > > > > On 3/24/2016 9:04 AM, jimlux wrote: > >> More like $40 in parts, without a board, etc. > >> The RPD-1 is $20.70 > >> LT1678/LT1679 is a nice low noise opamp that does rail to rail and is > >> about $5 > >> etc > >> > >> On 3/24/16 4:42 AM, Bob Camp wrote: > >>> Hi > >>> > >>> Pretty simple: > >>> > >>> Double balanced mixer, RPD-1 is one option, there are others. > >>> > >>> Fairly simple L/C lowpass between the mixer and an op-amp. > >>> > >>> 20 db positive (non-inverting) op-amp amplifier string after the mixer > >>> > >>> Output of the string goes to the sound card. Use a good (dual / quad) > >>> audio op amp > >>> > >>> Quadrature amp picks off the output of the first op amp stage, switch > >>> and resistors to set gain, pot to set op point. > >>> > >>> > >>> > >>> So what you have is an old style quadrature phase noise amp and “PLL”. > >>> More or less a very junior version > >>> of the 3048 test box. Like any setup of this sort, you check two > >>> similar oscillators. They run in quadrature and > >>> you do a few “measure this with switch in position A” sort of things > >>> to set things up each time. > >>> > >>> Nothing exotic. > >>> > >>> Bob > >>> > Any documentation on this $40 phase noise test set? > > Rick N6RK > >> > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the > > instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the > instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFTF 2016
Hello Bernd, Will make sure to not miss that lecture! :) Let's meet up! (Already sent some contact info off-list) My paper is 9:40 on Wednesday morning in the cross-correlation section: "Memory-Efficient High-Speed Algorithm for Multi-Tau PDEV Analysis" which is research I've done with Francois Vernotte and Enrico Rubiola. That session will be interesting, as the other three covers cross-correlation measures, where two of them goes into the cross-correlation catastrophe. One of those cross-correlation papers co-authed by Ulrich. I hope my paper can be of some interest, as I've took their papers and redone the calculations from scratch with a different approach, and have produces algorithms that allow for data to be decimated, hierarchically if you like. Proved it bias free while being at it. Full booklet of abstracts available here: http://eftf2016.s3.amazonaws.com/eftf2016_progbook.pdf Cheers, Magnus On 03/24/2016 07:13 PM, bneu...@t-online.de wrote: Hello Magnus I wiil be there. I will give a tutorial on piezoelectric resonator measurement on Monday afternoon. I will arrove on Sun afternoon and leave Thu afternoon. Would be great to have a Timenuts meeting Best regards Bernd DK1AG AXTAL Von meinem Samsung Galaxy Smartphone gesendet. Ursprüngliche Nachricht Von: Magnus Danielson Datum: 24.03.16 17:36 (GMT+01:00) An: Discussion of precise time and frequency measurement Cc: mag...@rubidium.se Betreff: [time-nuts] EFTF 2016 Fellow time-nuts, As I fixed many of the remaining issues with my travels to York today, I got curious about what fellow time-nuts will attend. I will be there the full week and will in fact arrive to York already on friday 1 april. I have a paper to present which I hope will be interesting. There is however only so much you can tell in 15 min and 4 pages. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Spectrum Analyzer Specifications
Bob... This is not related to your comment below but is still related to the thread.. Most SA's will generate noticeable internal distortion products at about -20 dBm to the first mixer. Internal or external attenuator will knock down the much louder 10 MHz from the Oscillator under test to that level. The old reliable "add 10 dB of attenuation" test and look for commensurate changes in distortion products vs the fundamental is essential for this. If you add 10 dB and the trash changes by 20 or more, then they are in the SA. Most close-in stuff won’t be affected, but as has been mentioned, the phase noise of the SA will likely be the limiting factor for what you will see unless you are testing a pretty bad synthesizer or using a current generation SA. With the modern boxes you can see more but it still won’t be clean enough to evaluate many XO's. You'd use the XO to find the PN of the SA! Tom Holmes, N8ZM -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Thursday, March 24, 2016 4:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Spectrum Analyzer Specifications Hi The board is pretty non-critical. It’s 90% audio. The biggest hassle is a power supply. You would *like* a fairly high voltage, at least if you are driving a spectrum analyzer. That may not be quite the case with a sound card. It depends a *lot* which one you are running. Something like a QA401: https://www.quantasylum.com/content/Products/QA401.aspx Would make a good target device. It’s based on the AKM 5397 So might some Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the advantage of a nice box and full USB isolation (ground loops are a pain). It also has drivers and all the OS hooks. The Janus is a bit more “DIY” with no drivers or interface (let alone isolation). The Janus is < 1/4 the price. The high voltage (+/- 18V linear regulated) supply approach makes a lot of sense with the QA401. It probably does not make as much sense with the Janus. Switching regulators of any sort are something I would strongly recommend against in a system like this that is trying to measure noise floor at audio …. The schematic changes a bit depending on what the target is. I can draw it up if there is a consensus on the target. One example: If the “sound card” is DC coupled, you can use it to indicate (and check) quadrature. If it’s an AC device, you need some sort of isolated output for another indicator. Bob > On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: > > I'd be willing to assist with board layout if someone wanted to make this > into a real project (e.g., fully developed schematic). TAPR might be talked > into supplying at least bare boards; we'd have to get a sense of demand > before committing to a full kit or assembled unit. > > John > > On 3/24/2016 9:04 AM, jimlux wrote: >> More like $40 in parts, without a board, etc. >> The RPD-1 is $20.70 >> LT1678/LT1679 is a nice low noise opamp that does rail to rail and is >> about $5 >> etc >> >> >> >> On 3/24/16 4:42 AM, Bob Camp wrote: >>> Hi >>> >>> Pretty simple: >>> >>> Double balanced mixer, RPD-1 is one option, there are others. >>> >>> Fairly simple L/C lowpass between the mixer and an op-amp. >>> >>> 20 db positive (non-inverting) op-amp amplifier string after the mixer >>> >>> Output of the string goes to the sound card. Use a good (dual / quad) >>> audio op amp >>> >>> Quadrature amp picks off the output of the first op amp stage, switch >>> and resistors to set gain, pot to set op point. >>> >>> >>> >>> So what you have is an old style quadrature phase noise amp and “PLL”. >>> More or less a very junior version >>> of the 3048 test box. Like any setup of this sort, you check two >>> similar oscillators. They run in quadrature and >>> you do a few “measure this with switch in position A” sort of things >>> to set things up each time. >>> >>> Nothing exotic. >>> >>> Bob >>> > Any documentation on this $40 phase noise test set? Rick N6RK >>> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions
Re: [time-nuts] Spectrum Analyzer Specifications
Hi That’s another good point about the need to work out a target device. Both of the possible target devices I mentioned have enough channels to do at least a dual channel measurement. That would add another mixer and a pair of power splitters along with another amp chain. The other part of that news is the RF drive power required goes up. You can do a pretty good job of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other gizmos will provide that without any amplifiers involved. Adding a 3 db splitter gets you into the 10 dbm range. That is getting fairly close to the limit for a lot of devices. You can add an amp. The ones that work without impacting the phase noise of a high quality OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep that sort of thing off the main board. So what is the second channel worth? The basic single channel design will get you into the -173 to -176 dbc / Hz range on a fairly high power pair of OCXO’s. The cross correlation “stuff” will get you past that point. Is that worth taking the BOM (without board and power supply) up to $80 or so? Consider that with the board and power supply, it likely is over $100. Would I do it as an accessory to a Janus or QA401? Maybe. You would need to pick one or the other. In the case of the Janus, there are more software issues and some noise floor testing. The QA401 is mighty expensive. The original idea was to use the sound card you already have …. Bob > On Mar 24, 2016, at 5:30 PM, Bruce Griffiths > wrote: > > If the software implements acquisition of cross power spectra > Then one could implement a near state of the art cross correlation PN test > set > based on this. > With a suitable preamp the sound card could also be used for power supply and > reference noise measurement. > > Bruce > > On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >> Hi >> >> The board is pretty non-critical. It’s 90% audio. The biggest hassle is a >> power supply. You would *like* a fairly high voltage, at least if you are >> driving a spectrum analyzer. That may not be quite the case with a sound >> card. It depends a *lot* which one you are running. Something like a QA401: >> >> https://www.quantasylum.com/content/Products/QA401.aspx >> >> Would make a good target device. It’s based on the AKM 5397 So might some >> Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the >> advantage of a nice box and full USB isolation (ground loops are a pain). >> It also has drivers and all the OS hooks. The Janus is a bit more “DIY” >> with no drivers or interface (let alone isolation). The Janus is < 1/4 the >> price. >> >> The high voltage (+/- 18V linear regulated) supply approach makes a lot of >> sense with the QA401. It probably does not make as much sense with the >> Janus. Switching regulators of any sort are something I would strongly >> recommend against in a system like this that is trying to measure noise >> floor at audio …. >> >> The schematic changes a bit depending on what the target is. I can draw it >> up if there is a consensus on the target. One example: If the “sound card” >> is DC coupled, you can use it to indicate (and check) quadrature. If it’s >> an AC device, you need some sort of isolated output for another indicator. >> >> Bob >> >>> On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: >>> >>> I'd be willing to assist with board layout if someone wanted to make this >>> into a real project (e.g., fully developed schematic). TAPR might be >>> talked into supplying at least bare boards; we'd have to get a sense of >>> demand before committing to a full kit or assembled unit. >>> >>> John >>> >>> >>> On 3/24/2016 9:04 AM, jimlux wrote: More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: > Hi > > Pretty simple: > > Double balanced mixer, RPD-1 is one option, there are others. > > Fairly simple L/C lowpass between the mixer and an op-amp. > > 20 db positive (non-inverting) op-amp amplifier string after the mixer > > Output of the string goes to the sound card. Use a good (dual / quad) > audio op amp > > Quadrature amp picks off the output of the first op amp stage, switch > and resistors to set gain, pot to set op point. > > > > So what you have is an old style quadrature phase noise amp and “PLL”. > More or less a very junior version > of the 3048 test box. Like any setup of this sort, you check two > similar oscillators. They run in quadrature and > you do a few “measure this with switch in position A” sort of things > to set things up each time. > > Nothing exotic. > > Bob > >> Any documentation on this $40 phase noise test set?
Re: [time-nuts] Spectrum Analyzer Specifications
Actually if you split the signal and then amplify each output independently then the PN performance of the RF amps is not too critical in that cross correlation averages the amplifier PN down as well as that of the mixers.I've done this with the Timepod using quite noisy amps as nothing else was immediately to hand.It just takes a little longer but works very well. I measured the output PN noise of an LTC6957 evaluation board this way using a couple of minicircuits HELA10s which are fairly noisy at 10MHz. If you don't need a PN floor below -180dBc/Hz then there are simple inexpensive one transistor (plus another for biasing) circuits that will achieve a few dB of gain with a PN noise floor well below -170dBc/Hz.The only real limitation is due to the presence of anti correlated thermal noise at the splitter outputs. Bruce On Friday, 25 March 2016 2:06 PM, Bob Camp wrote: Hi That’s another good point about the need to work out a target device. Both of the possible target devices I mentioned have enough channels to do at least a dual channel measurement. That would add another mixer and a pair of power splitters along with another amp chain. The other part of that news is the RF drive power required goes up. You can do a pretty good job of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other gizmos will provide that without any amplifiers involved. Adding a 3 db splitter gets you into the 10 dbm range. That is getting fairly close to the limit for a lot of devices. You can add an amp. The ones that work without impacting the phase noise of a high quality OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep that sort of thing off the main board. So what is the second channel worth? The basic single channel design will get you into the -173 to -176 dbc / Hz range on a fairly high power pair of OCXO’s. The cross correlation “stuff” will get you past that point. Is that worth taking the BOM (without board and power supply) up to $80 or so? Consider that with the board and power supply, it likely is over $100. Would I do it as an accessory to a Janus or QA401? Maybe. You would need to pick one or the other. In the case of the Janus, there are more software issues and some noise floor testing. The QA401 is mighty expensive. The original idea was to use the sound card you already have …. Bob > On Mar 24, 2016, at 5:30 PM, Bruce Griffiths > wrote: > > If the software implements acquisition of cross power spectra > Then one could implement a near state of the art cross correlation PN test > set > based on this. > With a suitable preamp the sound card could also be used for power supply and > reference noise measurement. > > Bruce > > On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >> Hi >> >> The board is pretty non-critical. It’s 90% audio. The biggest hassle is a >> power supply. You would *like* a fairly high voltage, at least if you are >> driving a spectrum analyzer. That may not be quite the case with a sound >> card. It depends a *lot* which one you are running. Something like a QA401: >> >> https://www.quantasylum.com/content/Products/QA401.aspx >> >> Would make a good target device. It’s based on the AKM 5397 So might some >> Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the >> advantage of a nice box and full USB isolation (ground loops are a pain).. >> It also has drivers and all the OS hooks. The Janus is a bit more “DIY” >> with no drivers or interface (let alone isolation). The Janus is < 1/4 the >> price. >> >> The high voltage (+/- 18V linear regulated) supply approach makes a lot of >> sense with the QA401. It probably does not make as much sense with the >> Janus. Switching regulators of any sort are something I would strongly >> recommend against in a system like this that is trying to measure noise >> floor at audio …. >> >> The schematic changes a bit depending on what the target is. I can draw it >> up if there is a consensus on the target. One example: If the “sound card” >> is DC coupled, you can use it to indicate (and check) quadrature. If it’s >> an AC device, you need some sort of isolated output for another indicator. >> >> Bob >> >>> On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: >>> >>> I'd be willing to assist with board layout if someone wanted to make this >>> into a real project (e.g., fully developed schematic). TAPR might be >>> talked into supplying at least bare boards; we'd have to get a sense of >>> demand before committing to a full kit or assembled unit. >>> >>> John >>> >>> >>> On 3/24/2016 9:04 AM, jimlux wrote: More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: > Hi > > Pretty simple: > > Double balanced mixer, RPD-1 is one opt
Re: [time-nuts] Spectrum Analyzer Specifications --> phase noise test set
Hi If you think the HELA10 is fun at 10 MHz, try it at 1 MHz :) The RPD-1 is a 1 MHz to 100 MHz part. That pretty well covers *most* of the low phase noise OCXO’s that people find running around in their junk boxes. To be “general purpose”, an amp would need to cover the same range. With two OCXO’s and two mixers, you would need 4 amps if they are after the splitters. By the time you get even the HELA10’s on heatsinks and boards you probably are around $40 an amplifier. Finding a part that is “as good as” the HELA10 is at 100 MHz, but at 1 MHz, is not very easy …. = Sort of on a bit different part of the same topic: There is nothing magic about the RPD-1 other than it is easy to dead bug and attach leaded parts to. If one is doing a pc board, the SYPD-1 is the same thing in a cheaper surface mount package. The $5.70 you save will pay for a few square inches of pc board. Bob > On Mar 24, 2016, at 9:31 PM, Bruce Griffiths > wrote: > > Actually if you split the signal and then amplify each output independently > then the PN performance of the RF amps is not too critical in that cross > correlation averages the amplifier PN down as well as that of the mixers.I've > done this with the Timepod using quite noisy amps as nothing else was > immediately to hand.It just takes a little longer but works very well. I > measured the output PN noise of an LTC6957 evaluation board this way using a > couple of minicircuits HELA10s which are fairly noisy at 10MHz. > If you don't need a PN floor below -180dBc/Hz then there are simple > inexpensive one transistor (plus another for biasing) circuits that will > achieve a few dB of gain with a PN noise floor well below -170dBc/Hz.The only > real limitation is due to the presence of anti correlated thermal noise at > the splitter outputs. > > Bruce > > >On Friday, 25 March 2016 2:06 PM, Bob Camp wrote: > > > Hi > > That’s another good point about the need to work out a target device. Both > of the possible target devices I mentioned have enough channels to do at > least a > dual channel measurement. That would add another mixer and a pair of power > splitters along with another amp chain. > > The other part of that news is the RF drive power required goes up. You can > do a pretty good job > of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other > gizmos will > provide that without any amplifiers involved. Adding a 3 db splitter gets you > into the 10 dbm > range. That is getting fairly close to the limit for a lot of devices. > > You can add an amp. The ones that work without impacting the phase noise of a > high quality > OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep > that sort > of thing off the main board. > > So what is the second channel worth? > > The basic single channel design will get you into the -173 to -176 dbc / Hz > range on a fairly high > power pair of OCXO’s. The cross correlation “stuff” will get you past that > point. Is that worth taking > the BOM (without board and power supply) up to $80 or so? Consider that with > the board and > power supply, it likely is over $100. > > Would I do it as an accessory to a Janus or QA401? Maybe. You would need to > pick one or > the other. In the case of the Janus, there are more software issues and some > noise floor testing. > The QA401 is mighty expensive. The original idea was to use the sound card > you already have …. > > Bob > > >> On Mar 24, 2016, at 5:30 PM, Bruce Griffiths >> wrote: >> >> If the software implements acquisition of cross power spectra >> Then one could implement a near state of the art cross correlation PN test >> set >> based on this. >> With a suitable preamp the sound card could also be used for power supply >> and >> reference noise measurement. >> >> Bruce >> >> On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >>> Hi >>> >>> The board is pretty non-critical. It’s 90% audio. The biggest hassle is a >>> power supply. You would *like* a fairly high voltage, at least if you are >>> driving a spectrum analyzer. That may not be quite the case with a sound >>> card. It depends a *lot* which one you are running. Something like a QA401: >>> >>> https://www.quantasylum.com/content/Products/QA401.aspx >>> >>> Would make a good target device. It’s based on the AKM 5397 So might some >>> Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the >>> advantage of a nice box and full USB isolation (ground loops are a pain).. >>> It also has drivers and all the OS hooks. The Janus is a bit more “DIY” >>> with no drivers or interface (let alone isolation). The Janus is < 1/4 the >>> price. >>> >>> The high voltage (+/- 18V linear regulated) supply approach makes a lot of >>> sense with the QA401. It probably does not make as much sense with the >>> Janus. Switching regulators of any sort are something I would strongly >>> recommend against in a system
Re: [time-nuts] Spectrum Analyzer Specifications
Hi Bob, Could you use a gate instead of an amp? Bob On Thu, 3/24/16, Bob Camp wrote: Subject: Re: [time-nuts] Spectrum Analyzer Specifications To: "Discussion of precise time and frequency measurement" Date: Thursday, March 24, 2016, 5:48 PM Hi That’s another good point about the need to work out a target device. Both of the possible target devices I mentioned have enough channels to do at least a dual channel measurement. That would add another mixer and a pair of power splitters along with another amp chain. The other part of that news is the RF drive power required goes up. You can do a pretty good job of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other gizmos will provide that without any amplifiers involved. Adding a 3 db splitter gets you into the 10 dbm range. That is getting fairly close to the limit for a lot of devices. You can add an amp. The ones that work without impacting the phase noise of a high quality OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep that sort of thing off the main board. So what is the second channel worth? The basic single channel design will get you into the -173 to -176 dbc / Hz range on a fairly high power pair of OCXO’s. The cross correlation “stuff” will get you past that point. Is that worth taking the BOM (without board and power supply) up to $80 or so? Consider that with the board and power supply, it likely is over $100. Would I do it as an accessory to a Janus or QA401? Maybe. You would need to pick one or the other. In the case of the Janus, there are more software issues and some noise floor testing. The QA401 is mighty expensive. The original idea was to use the sound card you already have …. Bob > On Mar 24, 2016, at 5:30 PM, Bruce Griffiths wrote: > > If the software implements acquisition of cross power spectra > Then one could implement a near state of the art cross correlation PN test set > based on this. > With a suitable preamp the sound card could also be used for power supply and > reference noise measurement. > > Bruce > > On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >> Hi >> >> The board is pretty non-critical. It’s 90% audio. The biggest hassle is a >> power supply. You would *like* a fairly high voltage, at least if you are >> driving a spectrum analyzer. That may not be quite the case with a sound >> card. It depends a *lot* which one you are running. Something like a QA401: >> >> https://www.quantasylum.com/content/Products/QA401.aspx >> >> Would make a good target device. It’s based on the AKM 5397 So might some >> Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the >> advantage of a nice box and full USB isolation (ground loops are a pain). >> It also has drivers and all the OS hooks. The Janus is a bit more “DIY” >> with no drivers or interface (let alone isolation). The Janus is < 1/4 the >> price. >> >> The high voltage (+/- 18V linear regulated) supply approach makes a lot of >> sense with the QA401. It probably does not make as much sense with the >> Janus. Switching regulators of any sort are something I would strongly >> recommend against in a system like this that is trying to measure noise >> floor at audio …. >> >> The schematic changes a bit depending on what the target is. I can draw it >> up if there is a consensus on the target. One example: If the “sound card” >> is DC coupled, you can use it to indicate (and check) quadrature. If it’s >> an AC device, you need some sort of isolated output for another indicator. >> >> Bob >> >>> On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: >>> >>> I'd be willing to assist with board layout if someone wanted to make this >>> into a real project (e.g., fully developed schematic). TAPR might be >>> talked into supplying at least bare boards; we'd have to get a sense of >>> demand before committing to a full kit or assembled unit. >>> >>> John >>> >>> >>> On 3/24/2016 9:04 AM, jimlux wrote: More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: > Hi > > Pretty simple: > > Double balanced mixer, RPD-1 is one option, there are others. > > Fairly simple L/C lowpass between the mixer and an op-amp. > > 20 db positive (non-inverting) op-amp amplifier string after the mixer > > Output of the string goes to the sound card. Use a good (dual / quad) > audio op amp > > Quadrature amp picks off the output of the first op amp stage, switch > and resistors to set gain, pot to set op point. > > > > S
Re: [time-nuts] Spectrum Analyzer Specifications --> phase noise test set
http://www.ko4bb.com/getsimple/index.php?id=low-noise-high-reverse-isolation-low-distortion-rf-amplifier Bruce On Friday, 25 March 2016 4:57 PM, Bruce Griffiths wrote: If 40-50dB reverse isolation is sufficient one can easily build suitable low gain (<10dB) amps with a single RF transistor (plus output transformer together with a low frequency transistor plus LED for bias stabilisation). Retrofitting a similar biasing scheme to the RF amps in some early HP PN measurement gear apparently does wonders for their PN at low offsets. One could even use a square wave drive from the output of a 74UHS125 or similar CMOS buffer to drive the phase detector input. There is a NIST paper that indicates a square wave LO drive for some mixers improves the performance somewhat. If reverse isolation isnt an issue a pushpull transformer feedback Norton amp works well. I just bought the HELA10's on evaluation PCBs complete with brass metalwork.. Bruce On Friday, 25 March 2016 4:02 PM, Bob Camp wrote: Hi If you think the HELA10 is fun at 10 MHz, try it at 1 MHz :) The RPD-1 is a 1 MHz to 100 MHz part. That pretty well covers *most* of the low phase noise OCXO’s that people find running around in their junk boxes. To be “general purpose”, an amp would need to cover the same range. With two OCXO’s and two mixers, you would need 4 amps if they are after the splitters. By the time you get even the HELA10’s on heatsinks and boards you probably are around $40 an amplifier. Finding a part that is “as good as” the HELA10 is at 100 MHz, but at 1 MHz, is not very easy …. = Sort of on a bit different part of the same topic: There is nothing magic about the RPD-1 other than it is easy to dead bug and attach leaded parts to. If one is doing a pc board, the SYPD-1 is the same thing in a cheaper surface mount package. The $5.70 you save will pay for a few square inches of pc board. Bob > On Mar 24, 2016, at 9:31 PM, Bruce Griffiths > wrote: > > Actually if you split the signal and then amplify each output independently > then the PN performance of the RF amps is not too critical in that cross > correlation averages the amplifier PN down as well as that of the mixers.I've > done this with the Timepod using quite noisy amps as nothing else was > immediately to hand.It just takes a little longer but works very well. I > measured the output PN noise of an LTC6957 evaluation board this way using a > couple of minicircuits HELA10s which are fairly noisy at 10MHz. > If you don't need a PN floor below -180dBc/Hz then there are simple > inexpensive one transistor (plus another for biasing) circuits that will > achieve a few dB of gain with a PN noise floor well below -170dBc/Hz.The only > real limitation is due to the presence of anti correlated thermal noise at > the splitter outputs. > > Bruce > > > On Friday, 25 March 2016 2:06 PM, Bob Camp wrote: > > > Hi > > That’s another good point about the need to work out a target device. Both > of the possible target devices I mentioned have enough channels to do at > least a > dual channel measurement. That would add another mixer and a pair of power > splitters along with another amp chain. > > The other part of that news is the RF drive power required goes up. You can > do a pretty good job > of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other > gizmos will > provide that without any amplifiers involved. Adding a 3 db splitter gets you > into the 10 dbm > range. That is getting fairly close to the limit for a lot of devices. > > You can add an amp. The ones that work without impacting the phase noise of a > high quality > OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep > that sort > of thing off the main board. > > So what is the second channel worth? > > The basic single channel design will get you into the -173 to -176 dbc / Hz > range on a fairly high > power pair of OCXO’s. The cross correlation “stuff” will get you past that > point. Is that worth taking > the BOM (without board and power supply) up to $80 or so? Consider that with > the board and > power supply, it likely is over $100. > > Would I do it as an accessory to a Janus or QA401? Maybe. You would need to > pick one or > the other. In the case of the Janus, there are more software issues and some > noise floor testing. > The QA401 is mighty expensive. The original idea was to use the sound card > you already have …. > > Bob > > >> On Mar 24, 2016, at 5:30 PM, Bruce Griffiths >> wrote: >> >> If the software implements acquisition of cross power spectra >> Then one could implement a near state of the art cross correlation PN test >> set >> based on this. >> With a suitable preamp the sound card could also be used for power supply >> and >> reference noise measurement. >> >> Bruce >> >> On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >>> Hi >>> >>> The board is pre
Re: [time-nuts] Spectrum Analyzer Specifications
One issue with CMOS gates is that a really quiet power supply is needed or the PN contribution of the gate is severely degraded. Fortunately this is an easy problem to solve.On solution is to use an independent noisy supply for each gate. Bruce On Friday, 25 March 2016 5:01 PM, Bob Stewart wrote: Hi Bob, Could you use a gate instead of an amp? Bob On Thu, 3/24/16, Bob Camp wrote: Subject: Re: [time-nuts] Spectrum Analyzer Specifications To: "Discussion of precise time and frequency measurement" Date: Thursday, March 24, 2016, 5:48 PM Hi That’s another good point about the need to work out a target device. Both of the possible target devices I mentioned have enough channels to do at least a dual channel measurement. That would add another mixer and a pair of power splitters along with another amp chain. The other part of that news is the RF drive power required goes up. You can do a pretty good job of saturating an RPD-1 with +7 dbm. Most (but not all) OCXO’s and other gizmos will provide that without any amplifiers involved. Adding a 3 db splitter gets you into the 10 dbm range. That is getting fairly close to the limit for a lot of devices. You can add an amp. The ones that work without impacting the phase noise of a high quality OCXO cost as much as the audio cards or USB devices. Cost wise, I’d keep that sort of thing off the main board. So what is the second channel worth? The basic single channel design will get you into the -173 to -176 dbc / Hz range on a fairly high power pair of OCXO’s. The cross correlation “stuff” will get you past that point. Is that worth taking the BOM (without board and power supply) up to $80 or so? Consider that with the board and power supply, it likely is over $100. Would I do it as an accessory to a Janus or QA401? Maybe. You would need to pick one or the other. In the case of the Janus, there are more software issues and some noise floor testing. The QA401 is mighty expensive. The original idea was to use the sound card you already have …. Bob > On Mar 24, 2016, at 5:30 PM, Bruce Griffiths wrote: > > If the software implements acquisition of cross power spectra > Then one could implement a near state of the art cross correlation PN test set > based on this. > With a suitable preamp the sound card could also be used for power supply and > reference noise measurement. > > Bruce > > On Thursday, March 24, 2016 04:54:47 PM Bob Camp wrote: >> Hi >> >> The board is pretty non-critical. It’s 90% audio. The biggest hassle is a >> power supply. You would *like* a fairly high voltage, at least if you are >> driving a spectrum analyzer. That may not be quite the case with a sound >> card. It depends a *lot* which one you are running. Something like a QA401: >> >> https://www.quantasylum.com/content/Products/QA401.aspx >> >> Would make a good target device. It’s based on the AKM 5397 So might some >> Janus boards. They are based on the earlier(?) AKM 5394. The QA401 has the >> advantage of a nice box and full USB isolation (ground loops are a pain). >> It also has drivers and all the OS hooks. The Janus is a bit more “DIY” >> with no drivers or interface (let alone isolation). The Janus is < 1/4 the >> price. >> >> The high voltage (+/- 18V linear regulated) supply approach makes a lot of >> sense with the QA401. It probably does not make as much sense with the >> Janus. Switching regulators of any sort are something I would strongly >> recommend against in a system like this that is trying to measure noise >> floor at audio …. >> >> The schematic changes a bit depending on what the target is. I can draw it >> up if there is a consensus on the target. One example: If the “sound card” >> is DC coupled, you can use it to indicate (and check) quadrature. If it’s >> an AC device, you need some sort of isolated output for another indicator. >> >> Bob >> >>> On Mar 24, 2016, at 1:31 PM, John Ackermann N8UR wrote: >>> >>> I'd be willing to assist with board layout if someone wanted to make this >>> into a real project (e.g., fully developed schematic). TAPR might be >>> talked into supplying at least bare boards; we'd have to get a sense of >>> demand before committing to a full kit or assembled unit. >>> >>> John >>> >>> >>> On 3/24/2016 9:04 AM, jimlux wrote: More like $40 in parts, without a board, etc. The RPD-1 is $20.70 LT1678/LT1679 is a nice low noise opamp that does rail to rail and is about $5 etc On 3/24/16 4:42 AM, Bob Camp wrote: > Hi > > Pretty simple: > > Double balanced mixer, RPD-1 is one option, there are others. > > Fairly simple L/C lowpass between the mixer and an op-amp. > > 20 db positive (non-inverting) op-amp amp
Re: [time-nuts] Austron 2010B
Naturally. -Chuck Harris paul swed wrote: Chuck if you do rescan them Diddiers site would be a great location. Regards Paul WB8TSL On Wed, Mar 23, 2016 at 5:11 PM, Chuck Harris wrote: Yes, those are copies of my manuals. I had hoped that Brooke would free them one day, but not so far. I plan to rescan them and release them. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
