[time-nuts] ✘NEO-M8N vs. NEO-M8T

Lady Heather can configure the various time pulse / PPS outputs on the Ublox receivers. (P keyboard menu) If the receiver supports sawtooth data, the current sawtooth value will be shown at the top of the screen (second column). It can also be shown in the plot area (GD will toggle the

Re: [time-nuts] Improving ocxo temp control

Thanks for your interesting replies. What I am actually trying to do is the following: I bough a small ocxo (size of half a ping-pong ball) that performs well (Abracon / AOCJY3_B 10Mhz) Reaching about 5*10E-11 kind of MDEV at low point ("kind of"… because a I use an HP52132a as input to

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

From: "Bob kb8tq" You have always been able to poll the time offset message on any of the uBlox modules. Getting that message to auto repeat was the traditional issue on there earlier products. A serial dump would tell you if u-center is getting the information by polling or

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi! From: "Bob kb8tq" Not by default You go through the 390 pages of their manual and eventually find the bits to turn this and that on. When you do, those magic bits will enable the data on a T version and will not enable it on a non-T version. At least that’s the way it’s

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi > On May 20, 2018, at 11:49 PM, Mark Sims wrote: > > I think what Gary really wants is a GPS receiver with the most stable PPS > output available. Unfortunately that’s not how any of these devices are designed to be used. They all ( including the Furuno ) have a

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi > On May 20, 2018, at 10:58 PM, Gary E. Miller wrote: > > Yo Bob! > > On Sun, 20 May 2018 22:53:37 -0400 > Bob kb8tq wrote: > >> If you look at the section under “timing (page 79)” in the uBlox >> manual you will find all the fun stuff that makes the T

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi You have always been able to poll the time offset message on any of the uBlox modules. Getting that message to auto repeat was the traditional issue on there earlier products. A serial dump would tell you if u-center is getting the information by polling or not. Bob > On May 21, 2018, at

Re: [time-nuts] Motorola GPS Antenna?

On 5/21/2018 8:24 AM, Clint Jay wrote: Found on eBay with no further information, can anyone identify? https://www.ebay.co.uk/itm/EX-MOD-Motorola-Antenna/323177970249?hash=item4b3ee87a49:g:tHIAAOSwUCZavUAe It looks like the standard "Marine" antenna, probably 5v, loads of gain (30 dB?), like

Re: [time-nuts] Motorola GPS Antenna?

Is it worth buying for that money if it is? On Mon, 21 May 2018 5:13 pm Dan Rae, wrote: > On 5/21/2018 8:24 AM, Clint Jay wrote: > > Found on eBay with no further information, can anyone identify? > > > > >

[time-nuts] Motorola GPS Antenna?

Found on eBay with no further information, can anyone identify? https://www.ebay.co.uk/itm/EX-MOD-Motorola-Antenna/323177970249?hash=item4b3ee87a49:g:tHIAAOSwUCZavUAe -- Clint. M0UAW IO83 *No trees were harmed in the sending of this mail. However, a large number of electrons were greatly

Re: [time-nuts] Improving ocxo temp control

Hi There are a lot of reasons an OCXO drifts. Temperature control is rarely the issue. More likely you are looking at the drift / wander characteristics of the crystal ( and components) in the OCXO. The simple answer is to leave it on for a while ( like weeks) to allow things to settle out a

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Should say 1.7 nsec we also plan to use the GCLK output for what I call a GPS PLL we have done it successfully with low cost u-blox with  E-11 frequency results. Bert Kehren   In a message dated 5/21/2018 7:49:20 AM Eastern Standard Time, time-nuts@febo.com writes:     Our answer was real

Re: [time-nuts] â NEO-M8N vs. NEO-M8T

On Sun, May 20, 2018 9:23 pm, Gary E. Miller wrote: > I do not see the keyword 'sawtooth' in the u-blox 8 doc. Can I buy a > clue? Sawtooth is what it looks like when you plot the quantization error of the PPS output, the documentation will just refer to it as quantization error. Referencing

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Yo Bob! On Mon, 21 May 2018 13:41:08 -0400 Bob kb8tq wrote: > Ok, are you trying to hold close to UTC or simply have a second that > is as close to 1 second as possible? Yes. One follows the other. RGDS GARY

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Yo Bob! On Mon, 21 May 2018 14:00:41 -0400 Bob kb8tq wrote: > >> Ok, are you trying to hold close to UTC or simply have a second > >> that is as close to 1 second as possible? > > > > Yes. One follows the other. > > Not really, you can have a source of seconds that are all

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi > On May 21, 2018, at 2:08 PM, Gary E. Miller wrote: > > Yo Bob! > > On Mon, 21 May 2018 14:00:41 -0400 > Bob kb8tq wrote: > Ok, are you trying to hold close to UTC or simply have a second that is as close to 1 second as possible? >>> >>> Yes.

Re: [time-nuts] Motorola GPS Antenna?

Motorola has worked with Matsushita Electric Industrial Co., Ltd (now known as Panasonic Corporation) since 1960s. Motorola sold their television division to Matsushita in 1970. — I believe that Motorola and Panasonic jointly developed this GPS antenna. While Motorola exited the GPS receiver

[time-nuts] NEO-M8N vs. NEO-M8T

Yes, the Ublox sends ps... whatever software that is processing the message is scaling it wrong. And labeling it wrong... qErr:-0.00105210 ps... that aint' right... no way... no how.. ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Yo Bob! On Mon, 21 May 2018 10:39:33 -0400 Bob kb8tq wrote: > > Yeah, which does me zero good real time. I'm putting the PPS into a > > TICC. My TICC has not way to accept real time corrections. So that > > does me no good, except as a post processing step. > > > > You

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi > On May 21, 2018, at 1:44 PM, Gary E. Miller wrote: > > Yo Bob! > > On Mon, 21 May 2018 13:41:08 -0400 > Bob kb8tq wrote: > >> Ok, are you trying to hold close to UTC or simply have a second that >> is as close to 1 second as possible? > > Yes. One

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

On Mon, May 21, 2018 at 5:54 PM, Gary E. Miller wrote: > Also, how does that get me to the gola of a good PPS to feed into the > Linux PPS kernel module? I doubt Linux would accept a patch to put > gpsd, and more, into the kernel to read GPS and adjust the PPS. Considering that

Re: [time-nuts] Improving ocxo temp control

First, be sure not to measure your HP52132A stability with the OCXO. What is your reference source? On Mon, May 21, 2018 at 7:12 PM, Bob kb8tq wrote: > Hi > > There are a lot of reasons an OCXO drifts. Temperature control is rarely the > issue. > More likely you are looking at

Re: [time-nuts] â NEO-M8N vs. NEO-M8T

Yo Chris! On Mon, 21 May 2018 08:23:27 -0500 "Chris Caudle" wrote: > The UBX-TIM-TP message is described in: > 32.21.8.1 Time Pulse Timedata > byte offset 8, name: qErr unit: ps > Quantization error of time pulse (not supported for the FTS product > variant). Notice the:

Re: [time-nuts] NEO-M8N vs. NEO-M8T

At 12:57 PM 5/21/2018, Gary E. Miller wrote: As the manual says: "Quantization error of time pulse (not supported for the FTS product variant)." The NEO-M8T is an FTS product. Are you sure about that? I thought the M8T was timing, and the M8F was FTS. Please check your firmware version

Re: [time-nuts] Motorola GPS Antenna?

Hi Since timing is everything to TimeNuts ….. :) The Motorola TV plant ( known as the Franklin Park North plant, not to be confused with Franklin Park South where they made …. errr ….. oscillators ) to Panasonic in 1974. The whole transaction came as quite a shock to the people involved. The

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Yo Chris! On Mon, 21 May 2018 13:55:23 -0500 "Chris Caudle" wrote: > On Mon, May 21, 2018 1:52 pm, Chris Caudle wrote: > > On Mon, May 21, 2018 1:19 pm, Gary E. Miller wrote: > >> Now, how to I tell the Linux kernel to apply that correction? > > > > Have the PPS

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi Backing up a bit …. If this is all about a system that can quantize to 52 ns at best … your ADEV plot shows everything *well* below that at all offsets you display. If you assume a +/- 1 LSB sort of quantization, you are out to 104 ns. That’s 10X anything on the plot. You would very much

Re: [time-nuts] time-nuts Digest, Vol 166, Issue 44

Mark, Ditto this. On 6T's and M8T's both. The 6T's do have an odd issue once in a while, right at the roll over limit from +10.whatever nS to -10.whatever nS, sometimes the sawtooth value comes in with the wrong sign. We were playing with the 6T's in a GPSDO, against a good crystal it

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi Ok, are you trying to hold close to UTC or simply have a second that is as close to 1 second as possible? Bob > On May 21, 2018, at 1:33 PM, Gary E. Miller wrote: > > Yo Bob! > > On Mon, 21 May 2018 10:39:33 -0400 > Bob kb8tq wrote: > >>> Yeah, which

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Yo Oleg! On Mon, 21 May 2018 18:05:08 +0300 Oleg Skydan wrote: > You can use uBlox u-center software to enable and disable messages > you need, the configuration can be saved. I have not done Windows since the year 2000. Not restarting now. RGDS GARY

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi Gary, It sounds like you need some special hardware that corrects the pulse timing before feeding it out. Richard Hambley's CNS-II did exactly that, using a programmable delay-line - see: https://www.cnssys.com/cnssys.php I seem to remember discussion about that in the Time-Nuts

Re: [time-nuts] NEO-M8N vs. NEO-M8T

On Mon, May 21, 2018 1:19 pm, Gary E. Miller wrote: > Now, how to I tell the Linux kernel to apply that correction? Have the PPS driver accept the correction before logging the PPS timestamp. -- Chris Caudle ___ time-nuts mailing list --

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Richard McCorkle  on his own GPSDO design had a separate PIC keep track of the saw tooth information from a M12 ad and subtract during the filter time constant and transferd the sum to the filter for processing.  Bert Kehren   In a message dated 5/21/2018 2:55:44 PM Eastern Standard Time,

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Yo Hal! On Sun, 20 May 2018 20:22:46 -0700 Hal Murray wrote: > g...@rellim.com said: > > Yeah, which does me zero good real time. I'm putting the PPS into > > a TICC. My TICC has not way to accept real time corrections. So > > that does me no good, except as a post

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Yo Scott! On Mon, 21 May 2018 13:08:06 -0500 Scott Newell wrote: > >The NEO-M8T is an FTS product. > > Are you sure about that? I thought the M8T was timing, and the M8F > was FTS. Please check your firmware version string against the table > on page 8. I stand

Re: [time-nuts] Motorola GPS Antenna?

I grew up downstate — NE of Quincy, IL and the Motorola TV mfg. operations at Quincy closed before the Franklin Park (North) plant. While there were assurances that Panasonic would continue operations at Quincy, local officials were caught “off guard” with decision to close a Motorola plant

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Hi Ok so they changed that from the earlier parts. Time marches on. Bob > On May 21, 2018, at 1:08 PM, Oleg Skydan wrote: > > > From: "Bob kb8tq" >> You have always been able to poll the time offset message on any of the uBlox >> modules. Getting that

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Yo Scott! On Sun, 20 May 2018 22:03:49 -0500 Scott Newell wrote: > At 09:23 PM 5/20/2018, Gary E. Miller wrote: > > >I do not see the keyword 'sawtooth' in the u-blox 8 doc. Can I buy > >a clue? > > UBX-TIM-TP, "Time Pulse Timedata". Look for "Quantization error

Re: [time-nuts] NEO-M8N vs. NEO-M8T

On Mon, May 21, 2018 1:52 pm, Chris Caudle wrote: > On Mon, May 21, 2018 1:19 pm, Gary E. Miller wrote: >> Now, how to I tell the Linux kernel to apply that correction? > > Have the PPS driver accept the correction before logging the PPS > timestamp. Or just have the PPS driver log the raw

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Gregory! On Mon, 21 May 2018 19:06:17 + Gregory Maxwell wrote: > My best guess is that the magnitude of sawtooth error is just not > large enough to matter for typical applications of linux PPS. No need to guess. I recently posted that the RasPi 3B granularity is 52 nano

[time-nuts] NEO-M8N vs. NEO-M8T

It looks like you have slipped a decimal point somewhere (also that "ps" label is wrong). I have an M8N running here and the report sawtooth errors are all within a +/- 10 ns span. (and LEA-5T is +/- 5ns). --- > Class: TIM(0xd) ID: TP(0x1), len: 0x10

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Yo Mark! On Mon, 21 May 2018 19:21:25 + Mark Sims wrote: > It looks like you have slipped a decimal point somewhere (also that > "ps" label is wrong). Yes, seemed 10x too high to me too. But the doc for UBX-TIM-TP clearly says 'ps'. UBX-TIM-TP: qErr ps

Re: [time-nuts] ˜NEO-M8N vs. NEO-M8T

See Marks recent message about whether the offset applies to the next or previous PPS. For the rest of this, I'll assume next since it's simpler to describe. We can discuss the other/harder case if you agree that the rest of this makes sense. g...@rellim.com said: > Your concept of 'real

Re: [time-nuts] NEO-M8N vs. NEO-M8T

On Mon, May 21, 2018 2:23 pm, Gary E. Miller wrote: > I look forward to your patch! My GPSDO doesn't have sawtooth error, so limited interest for me. How much does one of those u-blox modules cost? How would you tell if it made the gpsd performance better? I think that question came up a

[time-nuts] NEO-M8N vs. NEO-M8T

One thing to look out for when messing with sawtooth messages is the question of does the message come out before or after the PPS pulse... good look finding the answer in the receiver documentation... "After" seems to be the most common answer. That makes hardware/delay line compensation

Re: [time-nuts] NEO-M8N vs. NEO-M8T

On 21 May 2018 at 21:24, Mark Sims wrote: > > One thing to look out for when messing with sawtooth messages is the question of does the message come > out before or after the PPS pulse... good look finding the answer in the receiver documentation... > > "After" seems to be the most common answer.

Re: [time-nuts] NEO-M8N vs. NEO-M8T

Hi Simple answer on any GPSDO is always “that depends”. The sawtooth correction improves the PPS into the device by at least an order of magnitude on most GPS modules. Less noise in pretty much always equates to less noise out. It also takes care of hanging bridges ( sawtooth stuck to one side)

Re: [time-nuts] NEO-M8N vs. NEO-M8T

On May 21, 2018, at 11:19, Gary E. Miller wrote: > Now, how to I tell the Linux kernel to apply that correction? I honestly don’t understand how this would be used in a meaningful way via the Linux kernel. The nanoseconds of correction for the PPS signal seems a small nit

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Gary E. Miller writes: > Which I always thought was pointless, that only works for a fixed > antenna. Any GPS in a fixed position lab will have a good rooftop > antenna with clear skyview. Except when it doesn't and then the ability to survive on fewer visible/good satellites without going into

[time-nuts] A Request to the List

TVB is traveling and not on-line as much as usual, so in his absence I'm going to ask everyone to please consider his request a couple of weeks ago to think before you post. Please keep in mind that time-nuts isn't a chat room, and that every message doesn't require an individual response.

Re: [time-nuts] Sawtooth correction: next or previous PPS

Hi > On May 21, 2018, at 9:13 PM, Hal Murray wrote: > > > hol...@hotmail.com said: >> One thing to look out for when messing with sawtooth messages is the >> question of does the message come out before or after the PPS pulse... good >> look finding the answer in the

Re: [time-nuts] ✘NEO-M8N vs. NEO-M8T

Having a linux box (Pi) dedicated as a time server should mean you have consistent delays? To offload time server requests so they don't affect disciplining response/timing, would it be worthwhile having one Pi dedicated to being disciplined by the GPS, then have that pi discipline a second Pi

[time-nuts] Antenna cable delay compensation

A related question is: Do you use positive or negative numbers to set the antenna cable delay value? Again, most GPS receiver documentation does not say.I think that I've only seen it explicitly mentioned in the Trimble documentation and the Oscilloquartz Star-4 documentation. Also there

[time-nuts] Sawtooth correction: next or previous PPS

hol...@hotmail.com said: > One thing to look out for when messing with sawtooth messages is the > question of does the message come out before or after the PPS pulse... good > look finding the answer in the receiver documentation... Has anybody asked the manufacturers? This should be easy to