[time-nuts] Thunderbolt code phase measurement

I was losing messages for up to 4 seconds on some of the receivers (ResT?) so I commented out that message request. I need to go back and do some tests to see which ones are actually affected. --- > By "hosing" do you mean that you lose messages for the next second? That was

Re: [time-nuts] Thunderbolt code phase measurement

On May 16, 2018, at 15:01, Mark Sims wrote: > > Many thanks Peter for confirming what I suspected. The problem with the > Trimble receivers is that requesting the satellite C/A code data can hose up > a lot of them. So, I'm stuck with calculating the integer number of >

Re: [time-nuts] Thunderbolt code phase measurement

On May 16, 2018, at 13:58, Peter Monta wrote: > > "Code phase" represents where you are along the 1023-bit C/A code (each bit > or "chip" of this code lasts ~1 microsecond or ~300 meters). The > scaled-by-16 code phase will thus range from 0 to 16*1023. To get the full >

Re: [time-nuts] Thunderbolt code phase measurement

Hello Mark By "hosing" do you mean that you lose messages for the next second? That was a problem with the Resolution T too. I wanted to get ephemerides from the receiver so I ended up minimising lost messages by tracking satellites as they popped into view, and then requesting an ephemeris after

Re: [time-nuts] Thunderbolt code phase measurement

Hi Mark, I have been looking at this myself. Yes, you need to extend it with the 65-83 ms C/A code multiples, so Trimble provided a little too raw measures. This is perfectly clear as you read it. However, you are armed with the time of week for the message, also, there is messages so you can

[time-nuts] Thunderbolt code phase measurement

Many thanks Peter for confirming what I suspected. The problem with the Trimble receivers is that requesting the satellite C/A code data can hose up a lot of them. So, I'm stuck with calculating the integer number of milliseconds. How to do that? I do know my position to a few feet. I

Re: [time-nuts] Thunderbolt code phase measurement

> ... One value is "code phase" (along with PRN, sample length, sig level, > dopple, and time-of-measurement). This is a single precision floating > point number in units of 1/16 of a chip. Does anybody know how to massage > this value into either a carrier phase (in cycles) or a pseudorange

[time-nuts] Thunderbolt code phase measurement

The Trimble Thunderbolt has a message (0x5A) that outputs raw receiver measurement data. One value is "code phase" (along with PRN, sample length, sig level, dopple, and time-of-measurement). This is a single precision floating point number in units of 1/16 of a chip. Does anybody know how

[time-nuts] Thunderbolt command to reset the Date register.

Hi, I have a Trimble Thunderbolt. I'm looking for the command to reset the registry that blocks the update of the Date once full. Can someone help me? thanks, Luciano www.timeok.it ___ time-nuts mailing list -- time-nuts@febo.com

[time-nuts] Thunderbolt Locked/Unlocked pin on PCB?

Hi, I'm looking for a connection on the Thunderbolt board, a logical level, that showme when the GPSDO is locked to the GPS. Can someone help me? Luciano www.timeok.it ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

Re: [time-nuts] Thunderbolt - Lady Heather altitude does report abt 240m too high

Remember that GPS normally displays altitude with respect to the WGS84 datum geoid, not with respect to MSL. There can easily be a hundred feet or so of difference. Dana On Wed, Oct 25, 2017 at 9:18 PM, Arnold Tibus wrote: > Hello fellow time nuts, > > after the

[time-nuts] Thunderbolt - Lady Heather altitude does report abt 240m too high

Hello fellow time nuts, after the thunderbolt roll over problem I run the survey control in Lady Heather (48h). Since then I am getting always a wrong elevation number for my qth. Does anybody know the reason for that behavior? Is there a solution to get again the correct value? Kind regards

Re: [time-nuts] Thunderbolt question

Thanks everyone. This has given me a lot of things to check as I further investigate over the next few evenings. I'll let you know what I find. Chris > On Aug 5, 2017, at 3:07 PM, Charles Steinmetz wrote: > > Arthur wrote: > >> I’d say it would be an MMIC amp similar

Re: [time-nuts] Thunderbolt question

Arthur wrote: I’d say it would be an MMIC amp similar to this device [Avago MGA-87563] If a chip similar to the Avago part Arthur referenced is what is installed, which seems plausible, the 0.749v on the RF input (Pin 3) is a fault and is caused by an external source of voltage (3.417v)

Re: [time-nuts] Thunderbolt question

On Sat, 5 Aug 2017 10:47:40 -0400 paul swed wrote: > The .5 on the f connector is an issue and thats through the filter on top > of the board made of traces and 3 caps. From Arthur's digging I would agree > he found the chip or one that would work. But that chips voltages

Re: [time-nuts] Thunderbolt question

The .5 on the f connector is an issue and thats through the filter on top of the board made of traces and 3 caps. From Arthur's digging I would agree he found the chip or one that would work. But that chips voltages seem to match so most likely not the issue. What does the F connector measure to

[time-nuts] Thunderbolt question

Pin 1= 0v Pin 2= 0v Pin 3= 0.749V Pin 4= 4.892v Pin 5= 0v Pin 6= 3.417v I’d say it would be an MMIC amp similar to this device. It has the same pin-out so it is a possibility. The Amp In my newer version is an 23 db gain device but 8-pin so I Suspect your version may have similar specs. Here

Re: [time-nuts] Thunderbolt question

Hi, I've changed the blown MMBT3904 in the antenna sense circuit and I still have no 5V to the antenna. I measure 0.5V DC on the F connector. There are two Murata filters (F2 and F3) on the RF path to the antenna. In between the two silver colored filters is a 6 lead SOT package marked 51A.

Re: [time-nuts] Thunderbolt question

Thanks guys. I've opened up my T bolt and noticed a SOT23 packaged part has the top blown off. The PPS BNC jack has U19 beside it. The next part is blown. Could someone take a closeup of the five parts around U19? The intact parts are marked: 5Dz 1AM and two 2Az parts. Chris > On Aug 4,

[time-nuts] Thunderbolt question

Actually that isn't my photo I linked to but one I just Googled. That is probably a board revision most people don't have but it was the first one I saw so I used it just to show that the GPS receiver is part of the only circuit board and not another easily replaceable board like in some other

Re: [time-nuts] Thunderbolt question

Hi > On Aug 4, 2017, at 9:45 AM, paul swed wrote: > > Arthur > Thanks for the picture. I have a TBolt also and its working just fine at > the moment. > But one day it may not. As several people have mentioned lightnings an > issue. > > So going down the crazy thought path

Re: [time-nuts] Thunderbolt question

Arthur Thanks for the picture. I have a TBolt also and its working just fine at the moment. But one day it may not. As several people have mentioned lightnings an issue. So going down the crazy thought path for a moment. It appears from your pix you can figure out what the GPS receiver chip set

[time-nuts] Thunderbolt question

The Thunderbolt is a single board with the GPS receiver in the lower right between the oscillator case and the connectors in the photo in this link. https://www.eevblog.com/forum/testgear/trimble-thunderbolt-gps-disciplined-oscillator/?action=dlattach;attach=102948;image

Re: [time-nuts] Thunderbolt question

At 12:13 AM 8/4/2017, Chris Waldrup wrote: So no voltage out to antenna. I do have one of those 6V max polyphasers but we did get some really close strikes recently. Oh. As someone who lost a tbolt to lightning last year, I feel your pain. I've had to change the Oncore UT Plus receiver

Re: [time-nuts] Thunderbolt question

Couldn't wait till morning on this as it was on my mind this evening. I unplugged the Thunderbolt from the wall and plugged it back in. Immediately the frequency counter attached went from 9.. to zero then when it was powered back up went to the other side of 10 MHz at 10.000 and

Re: [time-nuts] Thunderbolt question

Thank you Didier. I'll check tomorrow for further issues. Chris > On Aug 3, 2017, at 10:05 PM, Didier Juges wrote: > > "If the Thunderbolt loses satellites, does it still put out a 10 Mhz > signal?" > > Yes of course. When that happens, the Thunderbolt is said to be in

Re: [time-nuts] Thunderbolt question

"If the Thunderbolt loses satellites, does it still put out a 10 Mhz signal?" Yes of course. When that happens, the Thunderbolt is said to be in holdover. On Aug 3, 2017 9:29 PM, "Chris Waldrup" wrote: > Hi, > > I just noticed the laptop that is always connected to my

[time-nuts] Thunderbolt question

Hi, I just noticed the laptop that is always connected to my Thunderbolt had a yellow block under COM1 on the Tboltmon program where it normally is green. Also the date up on the screen was in early July. Satellites were still shown. The counter I leave connected still shows a 10 Mhz output.

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

Hi Jim, On 08/02/2017 03:04 PM, jimlux wrote: On 8/2/17 5:16 AM, Magnus Danielson wrote: BTW, I saw that the JPL receiver at ISS got upgraded to support Galileo. Cool stuff. well, not exactly upgraded - the hardware didn't change - being bolted to the exterior of ISS inside a box inside

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

On 8/2/17 5:16 AM, Magnus Danielson wrote: BTW, I saw that the JPL receiver at ISS got upgraded to support Galileo. Cool stuff. well, not exactly upgraded - the hardware didn't change - being bolted to the exterior of ISS inside a box inside a box - it was a software change - which is

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

On 08/02/2017 01:20 AM, jimlux wrote: On 8/1/17 12:11 PM, Graham / KE9H wrote: Dider: This is a CDMA signal. (With a 'chip' rate that far exceeds the information rate.) If you put a different correlator on every multipath signal, which are each differently delayed in time, then they can be

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

On 8/1/17 12:11 PM, Graham / KE9H wrote: Dider: This is a CDMA signal. (With a 'chip' rate that far exceeds the information rate.) If you put a different correlator on every multipath signal, which are each differently delayed in time, then they can be independently demodulated. (Or time

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

On 8/1/17 11:11 AM, Didier Juges wrote: "The newer the receiver, the more horsepower in the silicon. In the case of GPS, that gives you more correlators to do DSP. The sensitivity improvement is a direct result of that. If you take a look at the guts of a TBolt, they date to the late 1990’s.

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

" having around 20 dB of gain at the antenna greatly decreases the effect of feed line loss on noise figure." And that would be consistent with usage for a timing receiver which is expected to have a well exposed antenna and a significant line length, as opposed to navigation receivers where the

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

Dider: This is a CDMA signal. (With a 'chip' rate that far exceeds the information rate.) If you put a different correlator on every multipath signal, which are each differently delayed in time, then they can be independently demodulated. (Or time shifted and added back together with some

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

"The newer the receiver, the more horsepower in the silicon. In the case of GPS, that gives you more correlators to do DSP. The sensitivity improvement is a direct result of that. If you take a look at the guts of a TBolt, they date to the late 1990’s. That’s a long time in silicon years …." It

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

Hi Jerry: The Trimble is the oldest mass produced GPS receiver I know of and because the early receivers used high gain antennas it seems that Trimble kept that idea for the newer designs. They like about 41 dB gain between the antenna and the input to the receiver.

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

Hi > On Jul 31, 2017, at 3:32 PM, Didier Juges wrote: > > The Thunderbolt is well known for not having the best sensitivity among GPS > receivers. It seems that timing receivers in general, particularly those of > the same generation as the Thunderbolt are not as sensitive

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

The Thunderbolt is well known for not having the best sensitivity among GPS receivers. It seems that timing receivers in general, particularly those of the same generation as the Thunderbolt are not as sensitive as navigation (possibly newer) GPS receivers. It may be because they are expected to

Re: [time-nuts] Thunderbolt - trouble locking with some types of antennas

Hello Jerry, I think the problem is not at the antenna, I consider the 58532A to be a lot better than these smal patch antennas. But the point is that modern receivers have a significant better sensivity! In my opinion, indoor position of any kind of antenna is not a good solution if you want to

[time-nuts] Thunderbolt - trouble locking with some types of antennas

Due to access problems, I run my Thunderbolt with a Symmetricom 58532A antenna placed indoor near a window facing South… can’t get much worse but most of the time it will be locked onto 3 or 4 satellites.I recently bought a www.leobodnar.com GPSDO for my SDR ham

Re: [time-nuts] Thunderbolt rollover glitch

On Sun, Jul 30, 2017, at 04:49 AM, Mark Sims wrote: > It looks like it took three hours for the effects of the rollover glitch > to mostly settle out. > > BTW, if you only use Lady Heather with a Thunderbolt, you can force the > rollover state from the command line or heather.cfg file by using

[time-nuts] Thunderbolt rollover glitch

It looks like it took three hours for the effects of the rollover glitch to mostly settle out. BTW, if you only use Lady Heather with a Thunderbolt, you can force the rollover state from the command line or heather.cfg file by using the /ro command line option. If you do that you won't have

[time-nuts] Thunderbolt rollover glitch

Attached is a plot of Thunderbolt data before and after the event. 2 seconds after rollover the Thunderbolt reported it was re-initializing the loop filter and 4 seconds after the event it reported is was starting to phase lock the 1PPS. The DAC jumped 0.023V V which is around 75 mHz of

Re: [time-nuts] Thunderbolt Monitor Kit by KO4BB

The Raspberry Pi idea is good because for your $100 it can do a few other tasks at the same time. It can run LH but also maybe she other services like NTP, a small web server and also a WiFi based backup server that backs up any notebook computers you have (it such a hassle to plug in an

Re: [time-nuts] Thunderbolt Monitor Kit by KO4BB

On 7/3/2017 11:50 AM, Mark Sims wrote: The K04BB device is a great little relatively inexpensive and compact Thunderbolt monitor. Another option is to use a Raspberry PI and the 7" color LCD touchscreen along with the latest Lady Heather code. A modification on the above option - instead

Re: [time-nuts] Thunderbolt Monitor Kit by KO4BB

k Sims <hol...@hotmail.com> Sent: Monday, July 3, 2017 9:50:35 AM To: time-nuts@febo.com Subject: [time-nuts] Thunderbolt Monitor Kit by KO4BB The K04BB device is a great little relatively inexpensive and compact Thunderbolt monitor. Another option is to use a Raspberry PI and the 7" colo

[time-nuts] Thunderbolt Monitor Kit by KO4BB

The K04BB device is a great little relatively inexpensive and compact Thunderbolt monitor. Another option is to use a Raspberry PI and the 7" color LCD touchscreen along with the latest Lady Heather code. I've added touchscreen support and some optimizations to the screen code for better

[time-nuts] Thunderbolt Monitor Kit by KO4BB . . . again

In 2016 I bought one of the KO4BB Thunderbolt Monitor Kits. I'm just now getting around to thinking about an enclosure in which to mount the device. I'd appreciate learning what others may have already done. Anyone care to share experience as to mounting and power? Pictures perhaps? Thanks.

[time-nuts] Thunderbolt Monitor Kit by KO4BB

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[time-nuts] Thunderbolt Rollover Testing

Plus Trimble's usage is rather misleading... you can do true overdetermined clock in either a static or moving environment... it properly requires more sats to be tracked than necessary to determine the time. Position hold mode (and Trimble's overdetermined clock mode) requires a fixed

Re: [time-nuts] Thunderbolt Rollover Testing

Hi > On Mar 6, 2017, at 1:38 AM, Mark Sims wrote: > > Does it have a saved/surveyed position? With a saved position you can > reasonable time performance with 1 sat. Without a saved position all bets > are off, there is no way for the receiver to determine the >

Re: [time-nuts] Thunderbolt Rollover Testing

On Mon, 6 Mar 2017 00:38:35 +, you wrote: >Does it have a saved/surveyed position? With a saved position you can >reasonable time performance with 1 sat. Without a saved position all bets >are off, there is no way for the receiver to determine the receiver/satellite >clock difference.

[time-nuts] Thunderbolt Rollover Testing

Does it have a saved/surveyed position? With a saved position you can reasonable time performance with 1 sat. Without a saved position all bets are off, there is no way for the receiver to determine the receiver/satellite clock difference. Trimble reports that the device is in

Re: [time-nuts] Thunderbolt Rollover Testing

On Sun, 5 Mar 2017 18:35:25 +0100, you wrote: >One thing a 6100 will let you do is to calibrate the PPS out of your “gizmo” >to +/- 5 ns (one sigma). While it’s >not an impressive number by TimeNuts standards, it is one of the few ways to >get that job done. I want to eventually characterize

Re: [time-nuts] Thunderbolt Rollover Testing

Hi > On Mar 5, 2017, at 6:31 AM, Trevor N. wrote: > > On Sat, 4 Mar 2017 20:39:45 -0800, you wrote: > >> Matthias Jelen did a test on the Trimble Thunderbolt here: >> >> https://www.febo.com/pipermail/time-nuts/2014-September/086664.html >>

Re: [time-nuts] Thunderbolt Rollover Testing

On Sat, 4 Mar 2017 20:39:45 -0800, you wrote: >Matthias Jelen did a test on the Trimble Thunderbolt here: > >https://www.febo.com/pipermail/time-nuts/2014-September/086664.html >https://www.febo.com/pipermail/time-nuts/2015-May/091805.html

Re: [time-nuts] Thunderbolt Rollover Testing

> I didn't see any reports of anyone (successfully) implementing a test for it. ... > I obtained all of the receivers the driver currently supports, along with a > Spirent GSS6100 simulator. ... Hi Trevor, Matthias Jelen did a test on the Trimble Thunderbolt here:

Re: [time-nuts] Thunderbolt Harmonics

hello to all, to put things right into perspective please note that the famous OCXO hp10811 is "only" specified with harmonics <25 dB (see page 11 of manual https://www.febo.com/pages/hp10811/HP10811AB-Manual.pdf). This device is but still often felt to be useful. Goetz Am 22.01.2017 um

Re: [time-nuts] Thunderbolt Harmonics

Bill, No offence taken at all. On the contrary, I really appreciate a great deal the effort you have gone to straightening out my misconceptions and blunders! This forum is such a great learning opportunity. I usually work with digital systems, so my RF and analog knowledge is sketchy at best.

Re: [time-nuts] Thunderbolt Harmonics

I'm trying to be gentle, Rhys. :) I work with these issues every day at work. Here are a few more comments. I assume you have the preamplifier in the spectrum analyzer turned off. The term "X harmonic" (such as 2nd or 3rd harmonic) means a multiplication of the fundamental signal by the given

Re: [time-nuts] Thunderbolt Harmonics

Hi > On Jan 20, 2017, at 11:22 AM, Tom Miller <tmiller11...@verizon.net> wrote: > > > - Original Message - From: "jimlux" <jim...@earthlink.net> > To: <time-nuts@febo.com> > Sent: Friday, January 20, 2017 8:34 AM > Subject: Re: [time-nut

Re: [time-nuts] Thunderbolt Harmonics

Hi > On Jan 19, 2017, at 11:48 PM, Rhys D wrote: > > Thanks for the detailed post Bill, > > I'm learning a lot here! > So the spectrum analyser is indeed a "trap for young players" > As you guessed, it is a Siglent SSA3000X series analyzer. > > I just looked at the same

Re: [time-nuts] Thunderbolt Harmonics

- Original Message - From: "jimlux" <jim...@earthlink.net> To: <time-nuts@febo.com> Sent: Friday, January 20, 2017 8:34 AM Subject: Re: [time-nuts] Thunderbolt Harmonics On 1/19/17 8:48 PM, Rhys D wrote: Thanks for the detailed post Bill, I'm learning a lot

Re: [time-nuts] Thunderbolt Harmonics

On 1/19/17 8:48 PM, Rhys D wrote: Thanks for the detailed post Bill, I'm learning a lot here! So the spectrum analyser is indeed a "trap for young players" As you guessed, it is a Siglent SSA3000X series analyzer. I just looked at the same signal again with varied attenuations dialed in on the

Re: [time-nuts] Thunderbolt Harmonics

Thanks for the detailed post Bill, I'm learning a lot here! So the spectrum analyser is indeed a "trap for young players" As you guessed, it is a Siglent SSA3000X series analyzer. I just looked at the same signal again with varied attenuations dialed in on the instrument (I am using an external

Re: [time-nuts] Thunderbolt Harmonics

You can't trust such low harmonic spurious measurements from a spectrum analyzer unless you know how the spurs change with input level. The second harmonic spur created in an amplifier or mixer inside the spectrum analyzer input will typically increase by 2 dB for every 1 dB of input level

Re: [time-nuts] Thunderbolt Harmonics

On 1/18/17 8:04 PM, Gerhard Hoffmann wrote: Am 18.01.2017 um 22:12 schrieb Bob Camp: Yeah, but it's easier (cheaper if you're paying for labor) just to buy a box of 10 filters at $30/each and stack them Be *very* careful cascading those Min-Circuits filters without putting some sort of

Re: [time-nuts] Thunderbolt Harmonics

On 1/18/17 6:25 PM, Tom Holmes wrote: Jim Lux... Note that the Keysight 33622 is basically an ARB, and not really intended to be an RF signal generator. Yes, but it has performance that is as good as the run of the mill signal generator. The big defect in the 33600 series is that it cannot

Re: [time-nuts] Thunderbolt Harmonics

Yeah, but it's easier (cheaper if you're paying for labor) just to buy a box of 10 filters at $30/each and stack them Be *very* careful cascading those Min-Circuits filters without putting some sort of isolation between them. You can get all sorts of wonky results as the reactances in one

Re: [time-nuts] Thunderbolt Harmonics

Am 18.01.2017 um 22:12 schrieb Bob Camp: Yeah, but it's easier (cheaper if you're paying for labor) just to buy a box of 10 filters at $30/each and stack them Be *very* careful cascading those Min-Circuits filters without putting some sort of isolation between them. You can get all sorts of

Re: [time-nuts] Thunderbolt Harmonics

for the intended frequency certainly can clean that up, of course. Tom Holmes, N8ZM -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: Wednesday, January 18, 2017 9:45 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Thunderbolt Harmonics On 1/18/17 4:33

Re: [time-nuts] Thunderbolt Harmonics

Thanks all for the extremely educational replies. On 19 January 2017 at 07:08, jimlux wrote: > On 1/18/17 8:56 AM, Bob Camp wrote: > >> HI >> >>> >>> the first time we ran the test (using a Keysight 33622 signal >>> generator) we saw significant 2nd and 3rd harmonics

Re: [time-nuts] Thunderbolt Harmonics

Hi > On Jan 18, 2017, at 1:08 PM, jimlux wrote: > > On 1/18/17 8:56 AM, Bob Camp wrote: >> HI >>> >>> the first time we ran the test (using a Keysight 33622 signal >>> generator) we saw significant 2nd and 3rd harmonics (50-60 dB down, >>> but easily detectable). A quick

Re: [time-nuts] Thunderbolt Harmonics

On 1/18/17 8:56 AM, Bob Camp wrote: HI the first time we ran the test (using a Keysight 33622 signal generator) we saw significant 2nd and 3rd harmonics (50-60 dB down, but easily detectable). A quick review of the data sheet.. Oh, the signal generator spec is only -43 dBc for frequencies

Re: [time-nuts] Thunderbolt Harmonics

Harmonic traps are another avenue to explore since the frequency is "fixed" at well below ppm. Which leaves the fundamental untouched. On Wed, Jan 18, 2017 at 5:21 AM, Charles Steinmetz wrote: > Rhys wrote: > > I was looking at the output of my Trimble Thunderbolt GPSDO

Re: [time-nuts] Thunderbolt Harmonics

Is what your seeing a harmonic (2nd? 3rd?) or a spur i.e what frequency is the "harmonic" ? The OP attached a spectrum analyzer screen shot to his initial post -- go back and have a look. It shows the harmonic series from 1 to 7, with H6 close to the noise level. Loudest harmonic is H2 at

Re: [time-nuts] Thunderbolt Harmonics

HI > On Jan 18, 2017, at 9:44 AM, jimlux wrote: > > On 1/18/17 4:33 AM, Artek Manuals wrote: >> R >> >> Is what your seeing a harmonic (2nd? 3rd?) or a spur i.e what frequency >> is the "harmonic" ? >> >> How are you measuring this ? (Spectrum analyzer ? make/model?) >>

Re: [time-nuts] Thunderbolt Harmonics

On 1/18/17 4:33 AM, Artek Manuals wrote: R Is what your seeing a harmonic (2nd? 3rd?) or a spur i.e what frequency is the "harmonic" ? How are you measuring this ? (Spectrum analyzer ? make/model?) More importantly and at the risk of displaying my naivety, what is the application that you are

Re: [time-nuts] Thunderbolt Harmonics

On 1/18/17 2:21 AM, Charles Steinmetz wrote: Rhys wrote: [1] F.L. Walls (NIST), F.G. Ascarrunz (SpectraDynamics), The Effect of Harmonic Distortion on Phase Errors in Frequency Distribution and Synthesis (year unknown, probably late '90s). 9th Euro Freq & Time Forum 1995 Besancon

Re: [time-nuts] Thunderbolt Harmonics

I suppose I should have said that Trimble specifies the Tbolt with harmonics -40dBc max, according to the User Guide v.5.0 (2003). Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Thunderbolt Harmonics

R Is what your seeing a harmonic (2nd? 3rd?) or a spur i.e what frequency is the "harmonic" ? How are you measuring this ? (Spectrum analyzer ? make/model?) More importantly and at the risk of displaying my naivety, what is the application that you are using the 10MHz source to feed and why

Re: [time-nuts] Thunderbolt Harmonics

Rhys wrote: I was looking at the output of my Trimble Thunderbolt GPSDO and was rather surprised to see really "loud" harmonics in there. ~ 60dB down from the 10Mhz signal. Welcome to the world of RF. Loudest harmonic at ~ -60dBc (dB with respect to carrier) is actually pretty good for a

Re: [time-nuts] Thunderbolt Harmonics

Hi If you look at the FCC transmitter regs, -60 dbc is “ok” for many transmitters. Bob > On Jan 17, 2017, at 9:40 PM, Rhys D wrote: > > Hi all, > > Before I start, let me say I'm rather a newbie at this sort of stuff so > please be gentle. > > I was looking at the output

Re: [time-nuts] Thunderbolt Harmonics

I'm not sure what the Thunderbolt specs state for harmonics, but -60 dB seems quite good to me. From: Rhys D <heyr...@gmail.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Tuesday, January 17, 2017 6:40 PM Subject: [time-nuts]

[time-nuts] Thunderbolt Harmonics

Hi all, Before I start, let me say I'm rather a newbie at this sort of stuff so please be gentle. I was looking at the output of my Trimble Thunderbolt GPSDO and was rather surprised to see really "loud" harmonics in there. ~ 60dB down from the 10Mhz signal. Can anyone here shed some light on

[time-nuts] Thunderbolt Repair Service

I have a Thunderbolt that has very low output. Is there anyone out there who will repair these ? Hopefully at a cost that is less than I can buy another one for. Thanks, Dick, W1KSZ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

Re: [time-nuts] Thunderbolt Schematic

Thanks much, I'll see how it looks tomorrow. 73 es HH, Dick, W1KSZ -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of EB4APL Sent: Tuesday, November 29, 2016 7:46 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts

Re: [time-nuts] Thunderbolt Schematic

If the unit is low on amplitude, there isn't likely much more than a buffer amp between the ocxo and 10 MHz output. On Tue, Nov 29, 2016 at 7:54 PM Bob Camp wrote: > Hi > > There is no schematic for the TBolt available. Based on Trimble’s approach > to keeping > all their IP

Re: [time-nuts] Thunderbolt Schematic

Hi There is no schematic for the TBolt available. Based on Trimble’s approach to keeping all their IP private (look at the survey side …), there will not be a schematic coming out from them. Since a good chunk of the functionality is in the FPGA’s and CPU’s, a schematic may be a tough thing

[time-nuts] Thunderbolt Schematic

>From the last e-mail I saw in 2014, there was no schematic available. Has anything changed lately, is one available ? I have one with low output that I would like to take a crack at fixing. Thanks, Dick, W1KSZ ___ time-nuts mailing list --

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On Thursday, September 22, 2016 01:37:02 AM Gerhard Hoffmann wrote: > Am 22.09.2016 um 00:24 schrieb Bruce Griffiths: > > Another issue is the requirement to trim the current sink for low output > > offset. > > And _that_ FET is made from Unobtainium. > > > If one takes advantage of the fact

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Am 22.09.2016 um 00:24 schrieb Bruce Griffiths: Another issue is the requirement to trim the current sink for low output offset. And _that_ FET is made from Unobtainium. If one takes advantage of the fact that the PLL imposes a low frequency cutoff to the PN measurements, the amplifier input

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Am 22.09.2016 um 00:24 schrieb Bruce Griffiths: For the later, Bruce commented that an jFET input stage would probably be more quiet. Gerhard Hoffman has designed a similar I must insist in my second "n" Hoffmann :-) system[3] that uses a couple of paralel low noise opamps instead of a

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On Wednesday, September 21, 2016 08:59:18 PM Attila Kinali wrote: > On Wed, 21 Sep 2016 09:16:18 -0700 > > Dan Rae wrote: > > On 9/21/2016 9:01 AM, David C. Partridge wrote: > > > Yes, I fear a timepod is a bit out of my budget (I can dream tho'). > > > Over here in the UK

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On Wed, September 21, 2016 1:59 pm, Attila Kinali wrote: > On Wed, 21 Sep 2016 09:16:18 -0700 > Dan Rae wrote: >> Pretty much all there, but the FET is hard to find now. > > If you want to build such an amplifier, then the first stage (aka the > jFET input and the first

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On Wed, 21 Sep 2016 09:16:18 -0700 Dan Rae wrote: > On 9/21/2016 9:01 AM, David C. Partridge wrote: > > Yes, I fear a timepod is a bit out of my budget (I can dream tho'). Over > > here in the UK PN measurement kit is a bit thin on the ground too. > > > > So I looked at

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On 9/21/2016 9:01 AM, David C. Partridge wrote: Yes, I fear a timepod is a bit out of my budget (I can dream tho'). Over here in the UK PN measurement kit is a bit thin on the ground too. So I looked at but that seemed a little thin

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

On 9/21/2016 8:01 AM, David C. Partridge wrote: Looks like all I've managed to do is measure the baseline noise of the analyser. Ho-hum looks like I need something a *lot* quieter to do these measurements. Indeed Dave, yes. I made the same mistake a few years ago when I tried to compare

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Yes, I fear a timepod is a bit out of my budget (I can dream tho'). Over here in the UK PN measurement kit is a bit thin on the ground too. So I looked at but that seemed a little thin on details. Or were you referring to something

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