[time-nuts] Newbie questions

Hi, I am a newbie to this list. I have downloaded the archives and read about 5,000 of the past messages. I plan on building my own GPSDO, probably using a LEA-6T (but LEA-7T or LEA-M8T would be good if I can find one affordably). I have a MTI 260 on order (although it could wind up being a 261

[time-nuts] HP5370B & HP5345B Front-End IC Redesign Effort

Hi, Wrote: Since the front end chips are mixed signal ASIC’s, it will take more than a bit of time to replace them directly. Re-doing the entire front panel board is the most likely way to “fix”the problem. The question is - why do that at all? Just do a PC instrument that does the same thing

Re: [time-nuts] Z3801 misbehaving

> I'm thinking of trying a new GPS board next. A bad GPS board won't prevent communication to the main CPU. You might try capturing the output when you power it on. It sends out something. I forget what, probably the ID string.. If that doesn't work, try a scope. You might have the PC

[time-nuts] low noise multiplication to 100 MHz

Actually not hard to do... lay out circuit board (free version of Eagle), have boards fab'd at Oshpark.com or your favorite Chinese proto shop (I like gojgo.com). Have solder paste stencil made at oshstencils.com. Squeege solder paste down with a credit card. Place components by hand.

[time-nuts] The cross-correlation catastrophe

Fellow time-nuts, Over a year and a half or so, we have been starting to grasp the various aspects of the cross-correlation catastrophe. This consists of two properties, one is the insertion of anti-correlated noise into the two channels, and then when cross-correlated it produced a

Re: [time-nuts] low noise multiplication to 100 MHz

Hi > On Jan 25, 2016, at 8:36 PM, Gerhard Hoffmann wrote: > > Am 25.01.2016 um 18:20 schrieb Graham / KE9H: >> There are clock distribution parts designed to do this low noise frequency >> conversion and distribution. >> >> Consider TI LMK04100 >> >> >> 150 fs class

Re: [time-nuts] low noise multiplication to 100 MHz

Hi Bert, I have noticed that if I have the right magnification, I can do amazing things. Even the tiny age related tremors that naturally occur in my hands reduce with magnification. The brain is a marvelous servo mechanism. Get a good 40x-80x zoom stereo microscope meant for dissection, the

Re: [time-nuts] Z3801 misbehaving

John I am no expert but I have been playing ( A lot) with my Z3801 during the last month, after having it in storage for 15 years ! What software program are you running, under what operating system? Can you see the satellites being tracked in the receiver status window in SATSTAT? on the

Re: [time-nuts] Z3801 misbehaving

John The 3801s are getting very old at this point. I know mine has started to show a loss of lock occasionally on the oscillator. Intermittent problems are very tough. What jumps out to me is the 27 volts. That seems low as I recall. I run at 48 V. I understand there were several models made so

Re: [time-nuts] Schlumberger FA2527 ocxo

> Hi > I have a OCXO marked Schlumberger Adret 622 used in Adret 4101A Frequency > standard receiver > I do not know if it is similar but performance seem OK > It is a cube of about 70 mm with DB9 output connector ; frequency is 5MHz > with external pot adj. > The ADEV seem good: data here >

[time-nuts] GPS jumps of -13.7 us?

Hi everyone, Has anyone else seen GPS time jump by -13.7 usec today? I just heard from several geographically quite distributed radio observatories that they have seen their GPS receiver(s) jump compared to their in-house standards. Regards, Paul Boven.

Re: [time-nuts] low noise multiplication to 100 MHz

Chuck Thank you for your advice, I will print it out and when needed experiment. We use SMD.s and two of our tem members are very good at it, I do limited stuff and have some tools but also a macular hole in one eye. In designs I try to stay with solder able SMD's and we have projects like

Re: [time-nuts] Z3801 misbehaving

On 1/26/2016 12:54 AM, Hal Murray wrote: I'm thinking of trying a new GPS board next. A bad GPS board won't prevent communication to the main CPU. You might try capturing the output when you power it on. It sends out something. I forget what, probably the ID string.. If that doesn't work,

Re: [time-nuts] Z3801 misbehaving

there are two versions a 24V version and a 48V version ... If you look at the back of the Z3801 there will be a "dot" on which voltage your unit is powered for . ...The 48V version is the more common. Since your unit is going through the full LED cycle on 27V supply I suspect that you do have

Re: [time-nuts] Z3801 misbehaving

John wrote: I even left it on over night. It may need longer than overnight to assemble an almanac and initialize everything. Leave it on for a week before you panic. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] GPS jumps of -13.7 us?

Indeed, multiple Z3801A GPSCON pages show an impulse step for by the amount you describe. I would describe the graphs as showing a positive TI step followed by negative TI step. My reading of the graphs shows that it is consistent with the 13.7 usec you describe. Am attempting to attach some

Re: [time-nuts] Z3801 misbehaving

Good comment on leaving it on for a long time if the almanac has been lost. You see nothing accept the green pwr led and I have seen 48 hours to lock. I added a batter 2 X AA and that keeps the almanac and enhances startup. But nothing like a modern 30 sec or less receiver. WB8TSL On Tue, Jan 26,

Re: [time-nuts] GPS jumps of -13.7 us?

On Tue, 26 Jan 2016 16:12:41 +0100 Paul Boven wrote: > Has anyone else seen GPS time jump by -13.7 usec today? > I just heard from several geographically quite distributed radio > observatories that they have seen their GPS receiver(s) jump compared to > their in-house

Re: [time-nuts] GPS jumps of -13.7 us?

Paul, I've received inquires about the 13 us jump since 8 PM last night (PST). Possibly related: http://www.navcen.uscg.gov/?Do=gpsShowNanu=2016008 Check your logs to see if your receiver is using SVN23/PRN32. /tvb - Original Message - From: "Paul Boven" To:

Re: [time-nuts] GPS jumps of -13.7 us?

In message <56a78ce9.20...@xs4all.nl>, Paul Boven writes: >Has anyone else seen GPS time jump by -13.7 usec today? >I just heard from several geographically quite distributed radio >observatories that they have seen their GPS receiver(s) jump compared to >their in-house standards.

Re: [time-nuts] GPS jumps of -13.7 us?

The GPSCon "International Z3801A web plot" page is still active: http://www.realhamradio.com/GPS_websites_list.htm Most of the entries are stale but here's a few that show the recent glitch nicely: http://www.shaunmerrigan.info/timeandfreq/gpscon/gpsstat.htm

Re: [time-nuts] GPS jumps of -13.7 us?

At 09:12 AM 1/26/2016, Paul Boven wrote: Has anyone else seen GPS time jump by -13.7 usec today? My tbolt locked ntp server saw an unusual spike of about that magnitude just after 00:00 1-26-2016 UTC. (The bump at 4 seconds is from the daily backup run.) -- newell N5TNL

Re: [time-nuts] low noise multiplication to 100 MHz

One last post on this off topic subject: Eyes. The younger folk will think eye problems amount to near or farsightedness... maybe a little astigmatism. The slightly older folk (37+) will know about presbyopia... the loss of your close working focus... your arms get shorter. Then there are the

Re: [time-nuts] Z3801 misbehavior

Thanks guys. I'll hook it up to the regular power supply and let it cook for a while. I have a uBlox board I want to check for jitter, but I'll need that '3801 to check it against. The fun part will just have to wait. ___ time-nuts mailing list --

[time-nuts] 58503A does not track

Hello list ! I have a HP 58503A who worked fine for two years. After a short power cut, it does not lock on GPS. I tried some commandsn including :SYST:PRESET but nothing works Here's a :SYSTEM:STATUS ? after the PRESET and after waiting a few hours : ---

Re: [time-nuts] GPS PRN 32

Tom This is what I sent unchecked Rich Text (HTML) now Has anyone noticed GPS problems today? It looks like PRN32 / SVN 23 went faulty yesterday and was taken out of service last night at 22:00 ZULU http://www.navcen.uscg.gov/?Do=gpsShowNanu=2016008 We've seen issues with a number of

Re: [time-nuts] low noise multiplication to 100 MHz

Jim, 3) Input and output level (?) the oscillator is a HCMOS output, so figure swinging about 3.5V Any multiplier configuration will produce lots of different harmonics, and will need fairly serious filtering after it if you want a clean 100MHz. If you have a 20MHz oscillator with

Re: [time-nuts] GPS jumps of -13.7 us?

Here's what my Z3801A saw using Z38XX. 00:00 on the graph = 06:00 UTC. My location is ~N50, W104. I don't know what SVNs were used. I'm not logging that data. Ed On 2016-01-26 11:00 AM, time-nuts-requ...@febo.com wrote: Message: 3 Date: Tue, 26 Jan 2016 16:12:41 +0100 From: Paul Boven

[time-nuts] what is acceptable harmonic content & level for a 10Mhz standard?

I have been working on a compact portable 10Mhz bench standard using both an FE FE5680A Rb oscillator and an Oscilloquartz ovenized crystal oscillator. I was curious to see how their short and long term stability would work out, and I needed something to drive my 6502 amp to pipe the signal to

Re: [time-nuts] GPS PRN 32

Hi, It seems that several SVNs (PRN 2, 6, 7, 9 and 23) got feed bad data. This is not the first instance, it seems that single SVNs have had bad data the last couple of days. When our 4 GPS receivers at work got "hit" at midnight, it got our attention. Interestingly enough they did not

Re: [time-nuts] what is acceptable harmonic content & level for a 10Mhz standard?

Walter that OCXO sure looks odd I would expect unfiltered to be a lot better then that. I would guess that several possibilities exist. The actual crystal is a 5 MHz and it feeds a doubler. The chain has something thats gone non-linear. -5dbm seems low to me. Oscilloquartz have a very fine

Re: [time-nuts] low noise multiplication to 100 MHz

Chuck, what do you use for a hot air source. The good ones are very expensive. Wonder if there is something for the hobbyist. Have seen a few repair videos where they used just used a hot air stripper. I had to yank a couple SMD resistors off a board the other day and had to use two soldering

Re: [time-nuts] what is acceptable harmonic content & level for a 10Mhz standard?

On 1/26/2016 11:52 AM, walter shawlee 2 wrote: I have been working on a compact portable 10Mhz bench standard using both an FE FE5680A Rb oscillator and an Oscilloquartz ovenized It is important for a 10 MHz source to launch a pure sine wave and also to have an accurate 50 ohm impedance at

[time-nuts] Noise of LT3042 vs ECL noise (was: Generating a solid PPS from 10Mhz source)

Moin, On Sun, 17 Jan 2016 17:32:58 +0100 Gerhard Hoffmann wrote: > BTW the extra quiet reference of the LT3042 is a current source, so > there is no real justification for the repeated claims here that ECL > must be noisy because of its integrated current source. I had a

Re: [time-nuts] low noise multiplication to 100 MHz

About 10 years ago I demonstrated a Hot Air Reflow method that is simple and needs no exotic tools and no heroic skills to solder surface mount devices. I also supply the solder paste in a syringe with a modified needle. The paste is Kester Easy Profile 256. You can see my method at:

Re: [time-nuts] GPS jumps of -13.7 us?

Paul Boven wrote: > Hi everyone, > > Has anyone else seen GPS time jump by -13.7 usec today? > I just heard from several geographically quite distributed radio > observatories that they have seen their GPS receiver(s) jump compared to > their in-house standards. We were able to track this down

Re: [time-nuts] what is acceptable harmonic content & level for a 10Mhz standard?

Hi If your OCXO is putting out less than 0 dbm, it’s broke. Given the way these parts are treated in the salvage loop, damage is not unusual. There are a *lot* of examples of surplus OCXO’s with low output. Normally it’s a damaged output cap or something like it. I’ve seen roughly half the

Re: [time-nuts] GPS jumps of -13.7 us?

Hi, On 01/26/2016 11:46 PM, Martin Burnicki wrote: Paul Boven wrote: Hi everyone, Has anyone else seen GPS time jump by -13.7 usec today? I just heard from several geographically quite distributed radio observatories that they have seen their GPS receiver(s) jump compared to their in-house

Re: [time-nuts] GPS jumps of -13.7 us?

Slashdot got it. http://it.slashdot.org/story/16/01/26/1735223/discrepancy-detected-in-gps-time On 01/26/2016 12:20 PM, Scott Newell wrote: > At 09:12 AM 1/26/2016, Paul Boven wrote: > >> Has anyone else seen GPS time jump by -13.7 usec today? > > My tbolt locked ntp server saw an unusual spike

Re: [time-nuts] GPS PRN 32

Magnus wrote: Interestingly enough they did not experience issues at the same time, it just started about the same time. Presumably, each rx would be affected when it added one or more corrupted satellites to the constellation it was using for its solution. Since each rx makes those