Re: [time-nuts] Microsemi XLi SAASM
Hi; I had a really good time speaking with one of you on the phone last week about XLI's and Cesium Standards but lost your contact info. You mentioned that you had XLI's SRS PRS10's. Please contact me directly with your contact information again. Thanks; Tom Knox 303-554-0307 act...@hotmail.com "Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein From: time-nuts on behalf of Steve - Home Sent: Sunday, March 29, 2020 12:33 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Microsemi XLi SAASM Mike, I’d be happy to give you call whenever it’s convenient for you. I am “voluntarily” retired and on SS for about a year now so loads of time on my hands but little excess money. What’s the best number to call you on? It appears the seller removed the GPS receiver from this XLi so I basically got a power supply and display. Very disappointing. All the best, Steve > On Mar 28, 2020, at 1:33 AM, MIKE ELDRIGE wrote: > > Steve, > There is no jumpers for the antenna voltage. > I have 2 saasm units and have many Xli units for parts which I would sell > Thanks, Mike > Some time give me a call and I can help what I can. > Very Best, Mike > > -Original Message- > From: time-nuts On Behalf Of Steve - Home > Sent: Friday, March 27, 2020 6:11 PM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Microsemi XLi SAASM > > Absolutely, but I’m hoping the XLi, like some of the later receivers, has a > method to select the antenna voltage. > > Steve > > > > >>> On Mar 27, 2020, at 8:06 PM, Dana Whitlow wrote: >> You could easily do what you want without modifying the receiver, >> using a >> 7805 or similar >> regulator and a pair of bias tees, inserted in the transmission line >> from the antenna. >> Dana On Fri, Mar 27, 2020 at 7:33 PM Steve - Home wrote: >>> I wondered if anyone has a user and/or service manual for the XLi SAASM? >>> Or any of the option modules? The one I received appears to have had >>> the L2 receiver removed. I’d also like to see if there’s a jumper or >>> software setting to change the antenna supply voltage from 12v to 5v. >>> Thanks for any assistance! >>> Steve >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go >>> to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go >> to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Microsemi XLi SAASM
Mike, I haven’t caught up with you in a while. I’d really like to find the GPS receiver for the XLi SAASM, and a 10MHz sine wave output module. I got some basic information from another guy but would appreciate an electronic copy of whatever you have. If you have a lot of XLi parts to get rid of I’d be happy to see a list and see what I can do. When would be a good time to call you? All the best, Steve > On Mar 28, 2020, at 1:33 AM, MIKE ELDRIGE wrote: > > Steve, > There is no jumpers for the antenna voltage. > I have 2 saasm units and have many Xli units for parts which I would sell > Thanks, Mike > Some time give me a call and I can help what I can. > Very Best, Mike > > -Original Message- > From: time-nuts On Behalf Of Steve - Home > Sent: Friday, March 27, 2020 6:11 PM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Microsemi XLi SAASM > > Absolutely, but I’m hoping the XLi, like some of the later receivers, has a > method to select the antenna voltage. > > Steve > > > > >> On Mar 27, 2020, at 8:06 PM, Dana Whitlow wrote: >> >> You could easily do what you want without modifying the receiver, >> using a >> 7805 or similar >> regulator and a pair of bias tees, inserted in the transmission line >> from the antenna. >> >> Dana >> >> On Fri, Mar 27, 2020 at 7:33 PM Steve - Home wrote: >>> >>> I wondered if anyone has a user and/or service manual for the XLi SAASM? >>> Or any of the option modules? The one I received appears to have had >>> the L2 receiver removed. I’d also like to see if there’s a jumper or >>> software setting to change the antenna supply voltage from 12v to 5v. >>> >>> Thanks for any assistance! >>> >>> Steve >>> >>> >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go >>> to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go >> to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 189, Issue 32
I think the point was missed about "losing some of the low power benefits". I also got an off-list reply that I'll address here keeping the sender private. I understand that "everything can be fixed with software", but as a hardware engineer, I prefer to save my power at the hardware level for true low-power solutions. There is a huge difference in power draw between updating a few registers for a counter, versus powering up an external IO interface, toggling an interrupt to wake up an entire power domain, having a microprocessor come out of sleep, reading the UNIX time register over the high energy IO bus, reading the standard time registers over the high energy IO bus, doing some math for a few hundred cycles, the writing out the corrected UNIX values over the high energy IO bus, then putting the microprocessor to sleep. It's probably several orders of magnitude more energy to fix it with software, then just having a better hardware design. I understand from reading the datasheet that it's not a "true" 32-bit UNIX time stamp in that it is not signed, and I'm aware that there are user registers provided in the part that can be used to expand the UNIX time counter - but that again requires an external part to talk over an IO bus that must be powered (I2C needs pull-ups to idle the bus - moving current on a trace uses a lot of power), and software time to "fix" a shortcoming (my opinion) that was designed into a brand new part that probably had the space. A counter running at 1Hz doesn't need to be fast, even if it was constrained to settling before a latch edge on a half cycle - 500mSec is an eternity in silicon time - so even using a simple low-gate-count ripple counter to fill 48 or 64-bits would have been better IMHO. Software has a power cost, and in what is advertised as an ultra-low power part, it seems to be a deficiency that the data is will require external conversion/manipulation so soon to a well known epoch issue. Spade = spade, even 40-bits would have been better than 32. All my opinion BTW, to each their own. -Tim Message: 6 > Date: Sun, 19 Apr 2020 18:15:26 -0700 > From: Hal Murray > Subject: Re: [time-nuts] A look inside the DS3231 > > [TRUNCATED] > > Not a problem. It's 2 lines of code. > > It's the same problem as the GPS week number roll over (WNRO). If the > reading > is less than the build time of the software, add in the overflow bit. > > That's good for 136 years. I wonder if any gear using those chips will > still > be running 100 years from now. > > -- > These are my opinions. I hate spam. > > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 189, Issue 32
tim.strom...@gmail.com said: > I understand that "everything can be fixed with software", but as a hardware > engineer, I prefer to save my power at the hardware level for true low-power > solutions. There is a huge difference in power draw between updating a few > registers for a counter, versus powering up an external IO interface, > toggling an interrupt to wake up an entire power domain, having a > microprocessor come out of sleep, reading the UNIX time register over the > high energy IO bus, reading the standard time registers over the high energy > IO bus, doing some math for a few hundred cycles, the writing out the > corrected UNIX values over the high energy IO bus, then putting the > microprocessor to sleep. It's probably several orders of magnitude more > energy to fix it with software, then just having a better hardware design. Nobody was suggesting anything that. The 32 bit register just ticks away. Aside from setting the time, nobody ever writes to it. Sometime in 2036, it overflows. The 2 lines of code go after you read the clock. t = readclock(); if (t < build time) t += 0x1; They only get executed when you are already up and running and doing stuff and read the clock because you want to know what time the chip thinks it is. - Actually, the 32 bit register will have to get updated occasionally. Leap seconds. At least until some kernel switches to using TAI time. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] For sale: 3 Cesium (FTS 4060, 2x PRS50) and Symmetricom S250, TrueTime XL-AK
Hi there all, I'm cleaning out my workshop, and so am selling some of my time stuff... 1: Datum FTS 4060 Cesium Time and Frequency Standard https://photos.app.goo.gl/m6mAMCkvLmbG4aKo7 I left this unplugged for ~4 months (yes, I know, I know), plugged it in, and it came up and got lock in ~45 minutes. Has relatively new backup batteries (replaced last year). Works perfectly, but could do with a new clip for holding the door closed (https://photos.app.goo.gl/pMtXAxfy1M5ztdHj9). As with many of these, if the battery is very low when it is first connected, the battery charger in it sometimes makes a GFCI trip 2: Two Datum PRS-50 Cesium Beam Primary Reference Source https://photos.app.goo.gl/UKkZJZYyCpGx6ipz9 I have two of these - one of them works, one of them doesn't (never locks, and the ionizer supply voltage is low - apparently this is often bad capacitors). Note that these are designed to mount in a 19" rack, and be powered from -48V. Comes with two (external) -48V supplies. 3: Symmetricom S250 NTP Network Time Server https://photos.app.goo.gl/74Uvu8wup6H9rVtt7 https://photos.app.goo.gl/gq4Y5cD8KdzyziWa7 Note: This is missing rack ears, and the edge of the case is damaged where some idiot tried to remove it from the rack without first unscrewing the ear... This is running Version 1.36 (the version that supports IPv6), and comes with the antenna. I also retrofitted a Rubidium oscillator for better holdover (Symmetricom X72). This was added in aftermarket, and has a small arduino to invert the lock signal. 4: TrueTime XL-AK https://photos.app.goo.gl/tJYtrG97oAoNxqtP7 I only played with this a little bit, and the firmware is sufficiently old that it doesn't know about the GPS rollover, so it thinks it is 1999 or something. It does not come with an antenna, but works with the standard 12V ones from Amazon. It has outputs for 10Mhz, 10Mpps, 1PPs, and one labeled IRIG-B (which I have not tested)... I'm asking $3,000 for everything, and want it to go as a set. As they are big and heavy (and may or may not count as hazmat for shipping), you will need to pick up in Northern Virginia (near Washington Dulles airport). Please reply (off-list) with any questions, etc. I also have a bunch of laser stuff which I'm also getting rid of -- this is engineering stuff from when Lightwave Electronics was acquired by JDS Uniphase -- most of this is DPSS / pumped diode stuff. Mostly non-working / needs alignment / etc. W -- I don't think the execution is relevant when it was obviously a bad idea in the first place. This is like putting rabid weasels in your pants, and later expressing regret at having chosen those particular rabid weasels and that pair of pants. ---maf ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Using speaker / earphone for PPS testing (not a question)
Maybe everyone but I knew, but I just did this and found it useful. 1 pps signal from some GPS are notoriously narrow and difficult to sync on and see on scopes. LED will barely light if some kind of stretcher is not used. If your purpose is ONLY to see if it's there or not, hook up a small speaker, earphone, amplified or not, and you can hear the tick-tick sound. I like DIYing and many times, I wonder if pps distribution circuit is working. I can tell a very short pulse that will barely register on LED is clearly audible. I thought I'd share. --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
It's easy to trigger on short pulses on most oscilloscopes if you follow these steps: (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. (2) Set the vertical coupling mode to DC. (3) Set the vertical gain (volts/div) and offset so that the baseline (OFF voltage between pulses) and pulse ON voltage should both be visible on the vertical scale. (4) Set the trigger coupling mode to DC and the trigger source to the proper channel. (5) Set the trigger voltage to the midpoint between the pulse OFF and ON voltage. (6) Set the trigger slope appropriately, depending on the polarity of the 1 PPS pulse. (7) Many oscilloscopes have a trigger indicator LED. It should flash visibly on each 1 PPS signal. (8) If you are using an analog scope which does NOT have a microchannel plate (which was used on the Tektronix 2467 family and a few other models), the pulse ON signal may be difficult to see at a fast time/div setting, even with a high scope intensity setting. But you can slow down the time/div of an analog scope to something easy to see, such as 10 ms/div. This will allow you to see a bright sweep each time the scope triggers, even if a short pulse can't be seen. (9) When using a digital oscilloscope, turn on the peak detect display mode. This allows the oscilloscope to keep a high sampling rate even if the time/div is set for a moderately slow sweep. If the 1 PPS signal is very short, you won't be able to hear it on a speaker with a direct connection as you describe. But you can use a pulse stretcher circuit (such as a 555 timer IC) to drive a LED or speaker with a long output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual timer IC), you can even configure one section as a one-shot and the other as a tone generator so that a beep is produced for each pulse. The 555 and 556 may be sold as LM555/LM556 or NE555/NE556. -- Bill Byrom N5BB Retired Tektronix Application Engineer On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: > Maybe everyone but I knew, but I just did this and found it useful. > 1 pps signal from some GPS are notoriously narrow and difficult to sync > on and see on scopes. LED will barely light if some kind of stretcher > is not used. If your purpose is ONLY to see if it's there or not, hook > up a small speaker, earphone, amplified or not, and you can hear the > tick-tick sound. > > I like DIYing and many times, I wonder if pps distribution circuit is > working. I can tell a very short pulse that will barely register on > LED is clearly audible. > I thought I'd share. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro second. T-bolt is quite short as well but I don't have a definite data. For those, speaker method worked just fine. I'm just sharing what I learned on happenstance. --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom wrote: It's easy to trigger on short pulses on most oscilloscopes if you follow these steps: (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. (2) Set the vertical coupling mode to DC. (3) Set the vertical gain (volts/div) and offset so that the baseline (OFF voltage between pulses) and pulse ON voltage should both be visible on the vertical scale. (4) Set the trigger coupling mode to DC and the trigger source to the proper channel. (5) Set the trigger voltage to the midpoint between the pulse OFF and ON voltage. (6) Set the trigger slope appropriately, depending on the polarity of the 1 PPS pulse. (7) Many oscilloscopes have a trigger indicator LED. It should flash visibly on each 1 PPS signal. (8) If you are using an analog scope which does NOT have a microchannel plate (which was used on the Tektronix 2467 family and a few other models), the pulse ON signal may be difficult to see at a fast time/div setting, even with a high scope intensity setting. But you can slow down the time/div of an analog scope to something easy to see, such as 10 ms/div. This will allow you to see a bright sweep each time the scope triggers, even if a short pulse can't be seen. (9) When using a digital oscilloscope, turn on the peak detect display mode. This allows the oscilloscope to keep a high sampling rate even if the time/div is set for a moderately slow sweep. If the 1 PPS signal is very short, you won't be able to hear it on a speaker with a direct connection as you describe. But you can use a pulse stretcher circuit (such as a 555 timer IC) to drive a LED or speaker with a long output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual timer IC), you can even configure one section as a one-shot and the other as a tone generator so that a beep is produced for each pulse. The 555 and 556 may be sold as LM555/LM556 or NE555/NE556. -- Bill Byrom N5BB Retired Tektronix Application Engineer On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: > Maybe everyone but I knew, but I just did this and found it useful. > 1 pps signal from some GPS are notoriously narrow and difficult to sync > on and see on scopes. LED will barely light if some kind of stretcher > is not used. If your purpose is ONLY to see if it's there or not, hook > up a small speaker, earphone, amplified or not, and you can hear the > tick-tick sound. > > I like DIYing and many times, I wonder if pps distribution circuit is > working. I can tell a very short pulse that will barely register on > LED is clearly audible. > I thought I'd share. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
