Re: [time-nuts] HP-5065a advise and purchase decision
Hi, I am new here. Are the Rubidium cell AND Rubidium Lamp still available either from HP/Agilant or another source? I am thinking of buying a HP-5065A and it would be nice if these critical parts were still available! Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Monday, July 02, 2012 12:48 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP-5065a advise and purchase decision Hi Yes, I have poked at the early ones (1980's). They are the only thing I have seen that will beat the HP 5065. There is also a lot of published data on them. Bob On Jul 1, 2012, at 5:43 PM, b...@lysator.liu.se wrote: > Tom, > >> Chris, >> >> The HP 5065A is one of the best Rb ever made. >> >> /tvb (iPhone4) > > Have you or any other list member had the opportunity to take measurements > on the ElmerPerkin/EG&G Space rubidiums (in a lab environment)? > > http://www.excelitas.com/Downloads/DTS_Frequency_Standards_RAFS.pdf > > -- > >Björn > > > ___ > 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] HP-5065a advise and purchase decision
On 07/03/2012 09:02 AM, Ron Ward wrote: Hi, I am new here. Are the Rubidium cell AND Rubidium Lamp still available either from HP/Agilant or another source? I am thinking of buying a HP-5065A and it would be nice if these critical parts were still available! They are not the parts that fails typically. If needed, they seems to be available here. Powersupplies typically fail. 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.
Re: [time-nuts] HP-5065a advise and purchase decision
Hi The cells only fail if you drop and break them. The lamps can wear out, but generally don't. The lamps can be found. The power transformer in any of these old beasts is the part that I worry about. Both HP and Tek used very conservative design rules on their transformers, they normally last a long time. Bob On Jul 3, 2012, at 3:02 AM, Ron Ward wrote: > Hi, I am new here. > Are the Rubidium cell AND Rubidium Lamp still available either from > HP/Agilant or another source? I am thinking of buying a HP-5065A and it > would be nice if these critical parts were still available! > Thanks, > Ron > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Bob Camp > Sent: Monday, July 02, 2012 12:48 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] HP-5065a advise and purchase decision > > Hi > > Yes, I have poked at the early ones (1980's). They are the only thing I > have seen that will beat the HP 5065. There is also a lot of published > data on them. > > Bob > > On Jul 1, 2012, at 5:43 PM, b...@lysator.liu.se wrote: > >> Tom, >> >>> Chris, >>> >>> The HP 5065A is one of the best Rb ever made. >>> >>> /tvb (iPhone4) >> >> Have you or any other list member had the opportunity to take > measurements >> on the ElmerPerkin/EG&G Space rubidiums (in a lab environment)? >> >> http://www.excelitas.com/Downloads/DTS_Frequency_Standards_RAFS.pdf >> >> -- >> >> Björn >> >> >> ___ >> 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] Magnus at NIST
On Jul 3, 2012, at 12:39 AM, Magnus Danielson wrote: > On 07/03/2012 04:03 AM, Tom Knox wrote: >> >> Magnus seen here in his recent trip to NIST is an obvious giant in the field >> of Time and Freq Metrology. Shown here in Peak Search mode. > > Despite the name, Flatirons has a peak, and I found it. Are they letting people in now, or is the fire still smoldering so access is restricted :( Boulder is a fun place regardless... Warner ___ 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] Magnus at NIST
For those who know Boulder, that is Bear Peak, site of recent wildfires. Magnus has just put out the last of it with his finger and being the cool guy those Swedes are did not suffer any burns. Thomas Knox > Date: Tue, 3 Jul 2012 08:39:55 +0200 > From: mag...@rubidium.dyndns.org > To: time-nuts@febo.com > Subject: Re: [time-nuts] Magnus at NIST > > On 07/03/2012 04:03 AM, Tom Knox wrote: > > > > Magnus seen here in his recent trip to NIST is an obvious giant in the > > field of Time and Freq Metrology. Shown here in Peak Search mode. > > Despite the name, Flatirons has a peak, and I found it. > > 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.
[time-nuts] Is Timelab with a Prologix-Eth and a PM6680 - working ?
I just got a PM6680/016 - Std. Osc + GPIB + 1.3Ghz -Chan.C The best my budget could afford :-) I would like to try out John's Timelab. But only have a Prologix-Ethernet GPIB adapter , no USB version. I was wondering if anyone can confirm that Timelab would work on a PM6680 , using a Prologix-Eth ? I can see the Prologix-Eth mentioned in the TimePod usermanual , but only in the Wavecrest DTS-2050/2070 series section. I'm totally "green" in Timelab & PM6680 , so any hints for a testsetup would be welcome. I'll connect my Tbolt to the PM6680-Ext.Ref , so i don't need an expensive internal osc. I was suggested by a fellow T-Nut , that connecting the Tbolt via a BNC-T , to both EXT-Ref & Chan-A , and then do ADEV with a 1 sec gatetime. Would be a good start. So i'll prob. start with that. Next i have a X72 & some FEI-5680A's , that i could connect to Chan-A TIA CFO - Timenut beginner ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
Using GPIB adapters over Ethernet can be difficult as the application software must open the device like "TCPIP::your_adapter_IP_address::gpib0::intfc" and, of course, accept an IP address somewhere. On Tue, Jul 3, 2012 at 4:34 PM, cfo wrote: > I just got a PM6680/016 - Std. Osc + GPIB + 1.3Ghz -Chan.C > The best my budget could afford :-) > > I would like to try out John's Timelab. > But only have a Prologix-Ethernet GPIB adapter , no USB version. > > I was wondering if anyone can confirm that Timelab would work on a > PM6680 , using a Prologix-Eth ? > > I can see the Prologix-Eth mentioned in the TimePod usermanual , but only > in the Wavecrest DTS-2050/2070 series section. > > I'm totally "green" in Timelab & PM6680 , so any hints for a testsetup > would be welcome. > > I'll connect my Tbolt to the PM6680-Ext.Ref , so i don't need an > expensive internal osc. > > I was suggested by a fellow T-Nut , that connecting the Tbolt via a > BNC-T , to both EXT-Ref & Chan-A , and then do ADEV with a 1 sec gatetime. > Would be a good start. So i'll prob. start with that. > > Next i have a X72 & some FEI-5680A's , that i could connect to Chan-A > > TIA > CFO - Timenut beginner > > > ___ > 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] Jackson Labs GPSTCXO - New Firmware
Back in April I talked about my experience with the Jackson Labs GPSTCXO. One thing I described is how if the user messed up and didn't disable serial echo as described in the manual, the GPSTCXO could get so confused that it would reboot. They have recently released a new firmware load that fixes the problem. I couldn't confuse it no matter what I did to it. The new firmware and the upgrade instructions are located on their support page. The '1 PPS enabled' version ouptputs 1 PPS at power up. The regular version outputs 1 PPS after getting a GPS fix. Ed ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
On 7/3/12 7:34 AM, cfo wrote: I just got a PM6680/016 - Std. Osc + GPIB + 1.3Ghz -Chan.C The best my budget could afford :-) I would like to try out John's Timelab. But only have a Prologix-Ethernet GPIB adapter , no USB version. I was wondering if anyone can confirm that Timelab would work on a PM6680 , using a Prologix-Eth ? Timelab certainly works with the Prologix GPIB.. I use it all the time (with a HP counter, not the PM6680). A few things to think about.. run the Prologix configurator first to make sure the darn thing is talking at the address you expect it to be at. I spent hours fooling with various things, carrying that darn Prologix up and down stairs between lab and office before I finally figured out it was my cheap $10 USB/Ethernet dongle that was screwing me up. (I wanted a "private" network at 192.168.1.x for this stuff) Once you have verified connectivity with the Prologix, then timelab works easily.. I'm still fooling with making it all work under Centos (not timelab.. python and sockets) and a 33120 ARB. (It works fine.. I'm just fooling with the python part) ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
On Tue, 03 Jul 2012 14:34:08 +, cfo wrote: > I just got a PM6680/016 - Std. Osc + GPIB + 1.3Ghz -Chan.C The best my > budget could afford :-) > > I would like to try out John's Timelab. But only have a > Prologix-Ethernet GPIB adapter , no USB version. > > I was wondering if anyone can confirm that Timelab would work on a > PM6680 , using a Prologix-Eth ? > Well (blush) I can ansver my own question here. Timelab autodetects the Prologix-Eth (with mac & ip) , and lists it below all the COMM-Ports. Nice work John ... So all i had to do was to select the detected Prologix , and set the PM6680 GPIB address. I'm acquiring data now , although not very impressive. I run my Tbolt signal through a Video Dist-Amp (400Mhz bw) , to get 6-channels. So i know the 75ohm imp there , but it's not been an issue so far. I feed the PM6680 Ext-Ref and Chan-A via a Dist-Amp output on a BNC-T. And have put a BNC-T on Chan-A with a 50ohm terminator on it. I have Chan-A set to 1Mohm , as i terminate the input via the BNC-T on Chan-A. But i wonder if the PM6680 Ext-Ref input already terminates with 50-ohm , and that could be the issue ?? The counter flickers occasionally in the last digit between 0 , 1 and 9 And Timelab says ADEV is 9.442-E-6 on T=1000 Secs. I would have expected something better LH says the ADEV is Osc ADEV is 5.442-E-13 on 1 Secs I wonder where i have FSCK'ed up , or is a Tbolt on Ext-Ref & the same signal on Chan-A supposed to show that ? CFO - (Feeling very T-Nut Beginner now) ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME A-B? On Tue, Jul 3, 2012 at 5:46 PM, cfo wrote: > On Tue, 03 Jul 2012 14:34:08 +, cfo wrote: > > > I just got a PM6680/016 - Std. Osc + GPIB + 1.3Ghz -Chan.C The best my > > budget could afford :-) > > > > I would like to try out John's Timelab. But only have a > > Prologix-Ethernet GPIB adapter , no USB version. > > > > I was wondering if anyone can confirm that Timelab would work on a > > PM6680 , using a Prologix-Eth ? > > > Well (blush) > > I can ansver my own question here. > Timelab autodetects the Prologix-Eth (with mac & ip) , and lists it below > all the COMM-Ports. Nice work John ... > > So all i had to do was to select the detected Prologix , and set the > PM6680 GPIB address. > > I'm acquiring data now , although not very impressive. > > I run my Tbolt signal through a Video Dist-Amp (400Mhz bw) , to get > 6-channels. So i know the 75ohm imp there , but it's not been an issue so > far. > > I feed the PM6680 Ext-Ref and Chan-A via a Dist-Amp output on a BNC-T. > And have put a BNC-T on Chan-A with a 50ohm terminator on it. > I have Chan-A set to 1Mohm , as i terminate the input via the BNC-T on > Chan-A. > > But i wonder if the PM6680 Ext-Ref input already terminates with 50-ohm , > and that could be the issue ?? > > The counter flickers occasionally in the last digit between 0 , 1 and 9 > > And Timelab says ADEV is 9.442-E-6 on T=1000 Secs. > > I would have expected something better > > LH says the ADEV is Osc ADEV is 5.442-E-13 on 1 Secs > > I wonder where i have FSCK'ed up , or is a Tbolt on Ext-Ref & the same > signal on Chan-A supposed to show that ? > > > CFO - (Feeling very T-Nut Beginner now) > > > > > ___ > 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
On Tue, 03 Jul 2012 18:11:26 +0200, Azelio Boriani wrote: > When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME > A-B? > It shows Data Type = time interval , i could also select frequency in the drop down box (This is the latest TimeLab - NonBeta). Now have i goofed ? Is time interval A->B inputs (blush) CFO ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
On Tue, 03 Jul 2012 18:11:26 +0200, Azelio Boriani wrote: > When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME > A-B? > I have uploaded a screenshot of the settings here http://img577.imageshack.us/img577/4171/timelabpm6680.png And the Timelab ADEV here http://img15.imageshack.us/img15/5705/76696902.png CFO Ps: I hope it's ok to ask here ... ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
Well, let's see: usually the Allan deviation is computed by collecting phase (time error) samples. You have to select time interval in TimeLab and on the PM6680 TIME A-B. If you want to use frequency samples (this is strange for me, never used frequency samples) then you must select frequency in TimeLab and FREQ A on the PM6680. Selecting TIME A-B requires that you use both the A and B inputs (start and stop) to time your signals but since you are trying to measure the TBolt with itself you must delay the signal going to A before it reaches B. Use a long coaxial cable as a delay line (50 meters should work). Measuring a signal with a delayed replica of itself can be useful to see how good is the counter. On Tue, Jul 3, 2012 at 6:26 PM, cfo wrote: > On Tue, 03 Jul 2012 18:11:26 +0200, Azelio Boriani wrote: > > > When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME > > A-B? > > > It shows Data Type = time interval , i could also select frequency in the > drop down box (This is the latest TimeLab - NonBeta). > > Now have i goofed ? > Is time interval A->B inputs (blush) > > CFO > > > > > ___ > 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
Yes, you can ask here about these things. Anyway, the best is to use the TBolt as a reference (not necessarily on the external ref of the counter) and test another oscillator or GPSDO. For example: feed the TBolt PPS to A, the GPSDO_under_test PPS to B and measure the stability of the time interval using TIME A-B. Ideally it should be a constant value (even if not exactly 0, but constant). The phase data (the time interval errors) can be collected and an Allan deviation computed. You can feed the TBolt PPS to A, a delayed replica to B (using 50 meters of coaxial cable) and test the PM6680 (and the thermal stability of the coaxial cable delay). Now, beware of the PM6680 uncertainty: read page 11-14 of the manual and see that the frequency uncertainty is LeastSignificantDigit= (500pS*frequency)/sampling_time. The default sampling time is 200mS so, for 10MHz you have 0.025Hz + or -. The time interval uncertainty is minimum 100pS. So, to try your setup (TBolt on EXT REF and A): first inform the TimeLab that you have 1 second frequency samples, then set the sampling time to 1 second (use FUNCTION button on the PM6680) and retry collecting data.In this case the predicted uncertainty is 0.005 (5E-10) and sholud average out to 5E-13 in 1000 seconds taking into consideratin that the full 12 digit resolution is available at the PM6680 GPIB (that is, the GPIB has more digits than the display can show, see page 11-18 of the manual). On Tue, Jul 3, 2012 at 6:37 PM, Azelio Boriani wrote: > Well, let's see: usually the Allan deviation is computed by collecting > phase (time error) samples. You have to select time interval in TimeLab and > on the PM6680 TIME A-B. If you want to use frequency samples (this is > strange for me, never used frequency samples) then you must select > frequency in TimeLab and FREQ A on the PM6680. > Selecting TIME A-B requires that you use both the A and B inputs (start > and stop) to time your signals but since you are trying to measure the > TBolt with itself you must delay the signal going to A before it reaches B. > Use a long coaxial cable as a delay line (50 meters should work). Measuring > a signal with a delayed replica of itself can be useful to see how good is > the counter. > > On Tue, Jul 3, 2012 at 6:26 PM, cfo wrote: > >> On Tue, 03 Jul 2012 18:11:26 +0200, Azelio Boriani wrote: >> >> > When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME >> > A-B? >> > >> It shows Data Type = time interval , i could also select frequency in the >> drop down box (This is the latest TimeLab - NonBeta). >> >> Now have i goofed ? >> Is time interval A->B inputs (blush) >> >> CFO >> >> >> >> >> ___ >> 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
On Tue, 03 Jul 2012 19:08:56 +0200, Azelio Boriani wrote: > Yes, you can ask here about these things. Anyway, the best is to use the > TBolt as a reference (not necessarily on the external ref of the > counter) and test another oscillator or GPSDO. For example: feed the > TBolt PPS to A, the GPSDO_under_test PPS to B and measure the stability > of the time interval using TIME A-B. Ideally it should be a constant > value (even if not exactly 0, but constant). The phase data (the time > interval errors) can be collected and an Allan deviation computed. Azelio , first ... Thanx for walking me through this. I'll try the above later on. But what you're saying is that when used as a TIC A->B , i don't need the TBolt on ext-ref ? , or do i need the TBolt on both Ext-Ref & on Chan-A ? If i don't use the TBolt on Ext-Ref , won't i get hit by having a Std-Osc installed ? I have a GPS Antenna-Splitter , another TBolt (just need to assemble the PSU) , and also a X72 Rubi & a few FEI-5680's. So i could try those when i'm a bit more familiar with the Counter & program. > >The default sampling time is 200mS > Ahhh ... Thanx now i know why my 1hr Trace Duration was so fast. I assumed that Timelab would set the sampling interval written in Timelab via GPIB. But i'll just select 1sec manually. > So, to try your setup (TBolt on EXT REF and A): first inform the TimeLab > that you have 1 second frequency samples, then set the sampling time to > 1 second (use FUNCTION button on the PM6680) and retry collecting > data.In this case the predicted uncertainty is 0.005 (5E-10) and sholud > average out to 5E-13 in 1000 seconds taking into consideratin that the > full 12 digit resolution is available at the PM6680 GPIB (that is, the > GPIB has more digits than the display can show, see page 11-18 of the > manual). > I will try this now , and i assume i should then select Frequency in the Data Type - In TimeLab , as i don't use A->B measurements .. Or ? I'll also dig into - How to calculate measurement errors , as you describe above. Regards CFO - Tnut-Beginner ___ 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] Magnus at NIST
On 07/03/2012 04:06 PM, Warner Losh wrote: On Jul 3, 2012, at 12:39 AM, Magnus Danielson wrote: On 07/03/2012 04:03 AM, Tom Knox wrote: Magnus seen here in his recent trip to NIST is an obvious giant in the field of Time and Freq Metrology. Shown here in Peak Search mode. Despite the name, Flatirons has a peak, and I found it. Are they letting people in now, or is the fire still smoldering so access is restricted :( Boulder is a fun place regardless... This was done before they had fires. Boulder is indeed a fun place. 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.
Re: [time-nuts] Magnus at NIST
On 07/03/2012 04:28 PM, Tom Knox wrote: For those who know Boulder, that is Bear Peak, site of recent wildfires. Magnus has just put out the last of it with his finger and being the cool guy those Swedes are did not suffer any burns. Hehe. Toss the two other two pictures, I did a hunt for a wild one and then you have the one with Dave's title :) 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.
Re: [time-nuts] 5345A with 10811A or 10544A
Seeking some idea here as to what happened in the Voltage trim concept in the 5345A I have been nursing two 5345As over the last few years. I kind of took it on faith that HP tied off the varactor trim Voltage line as there appears that they did not make a method to tickle this Voltage on either the 5345A with the 10811A or with the 10544A. One of the 5345As died and had to be solved. The problem was that its 10544A had died. The rock is bad on that one. However, since my desire is to add the Voltage trim adjust circuit that HP appears not to have installed I made some inspection of pins 5,6, and 7. It appears that the important item is pin 6 and it is floating in the 5345A. What gives? The 10544A schematic that I have shows minus EFC in as pin 6 and option for pin7 or internal 6.4 V for EFC plus. Inside the 10544A that I have, pin 6 has a wire to the prescribed 20k resistor and the varactor is installed. pin 7 is not connected. The second 5345A that I have been running has a 10811A in it and the 10811A schematic shows EFC to pin 6 (varactor anode) and varactor cathode to internal reference at 6.4V same as the 10544A that I have. Is it possible that HP just let pin 6 float in the 5345A assuming that the 10544As were to be installed without the varactor option? The nature of a floating anode is such that the diode goes into a very undesirable region, low Q high capacitance. Complete troubleville. The floating nature of this internal pin means that I need to restart all of my tuning an observations on these units. Unless I am missing something here? My idea is to make a Voltage reference onto one of the little removable option covers on the back with a pot to eliminate the cats breath tweaks to the trim cap in the 10811A and to finally nail the zero. Ha anybody been down this path before? Any suggestions? Any voices from the distant past of HP engineering? Regards; Greg ___ 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] HP-5065a advise and purchase decision
Hi: Okay, thanks for the information. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, July 03, 2012 1:12 AM To: time-nuts@febo.com Subject: Re: [time-nuts] HP-5065a advise and purchase decision On 07/03/2012 09:02 AM, Ron Ward wrote: > Hi, I am new here. > Are the Rubidium cell AND Rubidium Lamp still available either from > HP/Agilant or another source? I am thinking of buying a HP-5065A and it > would be nice if these critical parts were still available! They are not the parts that fails typically. If needed, they seems to be available here. Powersupplies typically fail. 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] HP-5065a advise and purchase decision
Hi: Okay thank you for the information. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Tuesday, July 03, 2012 4:08 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP-5065a advise and purchase decision Hi The cells only fail if you drop and break them. The lamps can wear out, but generally don't. The lamps can be found. The power transformer in any of these old beasts is the part that I worry about. Both HP and Tek used very conservative design rules on their transformers, they normally last a long time. Bob On Jul 3, 2012, at 3:02 AM, Ron Ward wrote: > Hi, I am new here. > Are the Rubidium cell AND Rubidium Lamp still available either from > HP/Agilant or another source? I am thinking of buying a HP-5065A and it > would be nice if these critical parts were still available! > Thanks, > Ron > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Bob Camp > Sent: Monday, July 02, 2012 12:48 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] HP-5065a advise and purchase decision > > Hi > > Yes, I have poked at the early ones (1980's). They are the only thing I > have seen that will beat the HP 5065. There is also a lot of published > data on them. > > Bob > > On Jul 1, 2012, at 5:43 PM, b...@lysator.liu.se wrote: > >> Tom, >> >>> Chris, >>> >>> The HP 5065A is one of the best Rb ever made. >>> >>> /tvb (iPhone4) >> >> Have you or any other list member had the opportunity to take > measurements >> on the ElmerPerkin/EG&G Space rubidiums (in a lab environment)? >> >> http://www.excelitas.com/Downloads/DTS_Frequency_Standards_RAFS.pdf >> >> -- >> >> Björn >> >> >> ___ >> 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. ___ 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] Jackson Labs GPSTCXO - New Firmware
> One thing I described is how if the user messed up and didn't disable > serial echo as described in the manual, the GPSTCXO could get so confused > that it would reboot It's worth keeping that echo mess in mind. I spent way too much time chasing one the other day. For each of my toys with a serial port, I keep a little text file with chunks of handy text that I can cut and paste. Usually the top line sets up the serial port. I think something changed recently, but I'm not sure what/where. I've had to add -echo to a few of those lines. Maybe newer releases of Linux/Fedora default to echo on. Maybe I'm using a new chip with a driver that defaults to echo on. Maybe it's always been this way and I just got lucky in the past. ... -- These are my opinions. I hate spam. ___ 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
When used as a time interval counter, the PM6680 (as well as other counters) counts the reference oscillator cycles + a residual got from an interpolator. Suppose you have to measure 234nS: with a 100MHz oscillator you count 23 cycles (the 100MHz is 10nS cycle) and then you are left with an additional 4nS. To account for the 4nS, various digital and analog techniques are available. Your 100MHz has to be stable at least only for the time you make the measurement, 234nS in this example. For this short time interval almost every oscillator will do and the final interpolator doesn't take any advantage from a stable oscillator: must be well designed and stable by itself. In short: if used as a frequency counter, yes, you have to feed a good reference at the EXT REF, when used as a time interval counter the good EXT REF is not so important, it is mandatory to use the good reference at one of the two counting inputs. Don't forget that with the PM6680 you can directly measure fractional frequency by using the MATH menu and the K=, L= and M= keys and smooth the measure by the STAT key. Later on you will discover that more resolution is necessary and you will be interested in counters such as the HP5370B (20pS) or the SR620 (25pS). Take a look at the PM6681 (50pS) too. On Tue, Jul 3, 2012 at 7:38 PM, cfo wrote: > On Tue, 03 Jul 2012 19:08:56 +0200, Azelio Boriani wrote: > > > Yes, you can ask here about these things. Anyway, the best is to use the > > TBolt as a reference (not necessarily on the external ref of the > > counter) and test another oscillator or GPSDO. For example: feed the > > TBolt PPS to A, the GPSDO_under_test PPS to B and measure the stability > > of the time interval using TIME A-B. Ideally it should be a constant > > value (even if not exactly 0, but constant). The phase data (the time > > interval errors) can be collected and an Allan deviation computed. > > Azelio , first ... Thanx for walking me through this. > > I'll try the above later on. > But what you're saying is that when used as a TIC A->B , i don't need the > TBolt on ext-ref ? , or do i need the TBolt on both Ext-Ref & on Chan-A ? > > If i don't use the TBolt on Ext-Ref , won't i get hit by having a Std-Osc > installed ? > > I have a GPS Antenna-Splitter , another TBolt (just need to assemble the > PSU) , and also a X72 Rubi & a few FEI-5680's. > > So i could try those when i'm a bit more familiar with the Counter & > program. > > > > > >The default sampling time is 200mS > > > Ahhh ... Thanx now i know why my 1hr Trace Duration was so fast. > I assumed that Timelab would set the sampling interval written in Timelab > via GPIB. But i'll just select 1sec manually. > > > > > So, to try your setup (TBolt on EXT REF and A): first inform the TimeLab > > that you have 1 second frequency samples, then set the sampling time to > > 1 second (use FUNCTION button on the PM6680) and retry collecting > > data.In this case the predicted uncertainty is 0.005 (5E-10) and sholud > > average out to 5E-13 in 1000 seconds taking into consideratin that the > > full 12 digit resolution is available at the PM6680 GPIB (that is, the > > GPIB has more digits than the display can show, see page 11-18 of the > > manual). > > > > I will try this now , and i assume i should then select Frequency in the > Data Type - In TimeLab , as i don't use A->B measurements .. Or ? > > > I'll also dig into - How to calculate measurement errors , as you > describe above. > > > Regards > CFO - Tnut-Beginner > > > > > ___ > 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
Hi That works out fine *if* the edges are close to each other. Consider one edge arriving a half second before the other one. Then the reading is off by a nanosecond for each 2 ppb the reference is off frequency. If you have a TCXO as the reference for your counter, you likely will be further off than that. There are a *lot* of surplus counters that originally went into setups with external references. They have (at best) a loose TCXO for a standard when the reference is not present. Bob On Jul 3, 2012, at 3:32 PM, Azelio Boriani wrote: > When used as a time interval counter, the PM6680 (as well as other > counters) counts the reference oscillator cycles + a residual got from an > interpolator. Suppose you have to measure 234nS: with a 100MHz oscillator > you count 23 cycles (the 100MHz is 10nS cycle) and then you are left with > an additional 4nS. To account for the 4nS, various digital and analog > techniques are available. Your 100MHz has to be stable at least only for > the time you make the measurement, 234nS in this example. For this short > time interval almost every oscillator will do and the final interpolator > doesn't take any advantage from a stable oscillator: must be well designed > and stable by itself. In short: if used as a frequency counter, yes, you > have to feed a good reference at the EXT REF, when used as a time interval > counter the good EXT REF is not so important, it is mandatory to use the > good reference at one of the two counting inputs. Don't forget that with > the PM6680 you can directly measure fractional frequency by using the MATH > menu and the K=, L= and M= keys and smooth the measure by the STAT key. > Later on you will discover that more resolution is necessary and you will > be interested in counters such as the HP5370B (20pS) or the SR620 (25pS). > Take a look at the PM6681 (50pS) too. > > On Tue, Jul 3, 2012 at 7:38 PM, cfo wrote: > >> On Tue, 03 Jul 2012 19:08:56 +0200, Azelio Boriani wrote: >> >>> Yes, you can ask here about these things. Anyway, the best is to use the >>> TBolt as a reference (not necessarily on the external ref of the >>> counter) and test another oscillator or GPSDO. For example: feed the >>> TBolt PPS to A, the GPSDO_under_test PPS to B and measure the stability >>> of the time interval using TIME A-B. Ideally it should be a constant >>> value (even if not exactly 0, but constant). The phase data (the time >>> interval errors) can be collected and an Allan deviation computed. >> >> Azelio , first ... Thanx for walking me through this. >> >> I'll try the above later on. >> But what you're saying is that when used as a TIC A->B , i don't need the >> TBolt on ext-ref ? , or do i need the TBolt on both Ext-Ref & on Chan-A ? >> >> If i don't use the TBolt on Ext-Ref , won't i get hit by having a Std-Osc >> installed ? >> >> I have a GPS Antenna-Splitter , another TBolt (just need to assemble the >> PSU) , and also a X72 Rubi & a few FEI-5680's. >> >> So i could try those when i'm a bit more familiar with the Counter & >> program. >> >> >>> >>> The default sampling time is 200mS >>> >> Ahhh ... Thanx now i know why my 1hr Trace Duration was so fast. >> I assumed that Timelab would set the sampling interval written in Timelab >> via GPIB. But i'll just select 1sec manually. >> >> >> >>> So, to try your setup (TBolt on EXT REF and A): first inform the TimeLab >>> that you have 1 second frequency samples, then set the sampling time to >>> 1 second (use FUNCTION button on the PM6680) and retry collecting >>> data.In this case the predicted uncertainty is 0.005 (5E-10) and sholud >>> average out to 5E-13 in 1000 seconds taking into consideratin that the >>> full 12 digit resolution is available at the PM6680 GPIB (that is, the >>> GPIB has more digits than the display can show, see page 11-18 of the >>> manual). >>> >> >> I will try this now , and i assume i should then select Frequency in the >> Data Type - In TimeLab , as i don't use A->B measurements .. Or ? >> >> >> I'll also dig into - How to calculate measurement errors , as you >> describe above. >> >> >> Regards >> CFO - Tnut-Beginner >> >> >> >> >> ___ >> 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] Is Timelab with a Prologix-Eth and a PM6680 - working ?
Yes, you are right: my example was, for this reason, limited to a couple hundred nS. Usually testing PPSes or 10MHz sources leads to very small time intervals so the resolution of the interpolator dominates. For time intervals beyond the nS figures it is better to consider a stable reference. Another problem of the start-stop mechanism is the lack of the negative time interval capability of the PM6680/1: you can swap A and B inputs on the fly but you loose one (or more) samples. I have seen my PM8861 outputting wrong samples as the PPSes cross each other: usually a 4.9E-01 seconds sample is output before the correct reading resumes. Very surprising was the correct negative output (I suppose when the time interval is under the interpolator window) got when the two PPSes were very very slowly crossing: a long list of negative values before the usual 9.999E-01 output. On Tue, Jul 3, 2012 at 9:42 PM, Bob Camp wrote: > Hi > > That works out fine *if* the edges are close to each other. > > Consider one edge arriving a half second before the other one. Then the > reading is off by a nanosecond for each 2 ppb the reference is off > frequency. If you have a TCXO as the reference for your counter, you likely > will be further off than that. There are a *lot* of surplus counters that > originally went into setups with external references. They have (at best) a > loose TCXO for a standard when the reference is not present. > > Bob > > On Jul 3, 2012, at 3:32 PM, Azelio Boriani wrote: > > > When used as a time interval counter, the PM6680 (as well as other > > counters) counts the reference oscillator cycles + a residual got from an > > interpolator. Suppose you have to measure 234nS: with a 100MHz oscillator > > you count 23 cycles (the 100MHz is 10nS cycle) and then you are left with > > an additional 4nS. To account for the 4nS, various digital and analog > > techniques are available. Your 100MHz has to be stable at least only for > > the time you make the measurement, 234nS in this example. For this short > > time interval almost every oscillator will do and the final interpolator > > doesn't take any advantage from a stable oscillator: must be well > designed > > and stable by itself. In short: if used as a frequency counter, yes, you > > have to feed a good reference at the EXT REF, when used as a time > interval > > counter the good EXT REF is not so important, it is mandatory to use the > > good reference at one of the two counting inputs. Don't forget that with > > the PM6680 you can directly measure fractional frequency by using the > MATH > > menu and the K=, L= and M= keys and smooth the measure by the STAT key. > > Later on you will discover that more resolution is necessary and you will > > be interested in counters such as the HP5370B (20pS) or the SR620 (25pS). > > Take a look at the PM6681 (50pS) too. > > > > On Tue, Jul 3, 2012 at 7:38 PM, cfo wrote: > > > >> On Tue, 03 Jul 2012 19:08:56 +0200, Azelio Boriani wrote: > >> > >>> Yes, you can ask here about these things. Anyway, the best is to use > the > >>> TBolt as a reference (not necessarily on the external ref of the > >>> counter) and test another oscillator or GPSDO. For example: feed the > >>> TBolt PPS to A, the GPSDO_under_test PPS to B and measure the stability > >>> of the time interval using TIME A-B. Ideally it should be a constant > >>> value (even if not exactly 0, but constant). The phase data (the time > >>> interval errors) can be collected and an Allan deviation computed. > >> > >> Azelio , first ... Thanx for walking me through this. > >> > >> I'll try the above later on. > >> But what you're saying is that when used as a TIC A->B , i don't need > the > >> TBolt on ext-ref ? , or do i need the TBolt on both Ext-Ref & on Chan-A > ? > >> > >> If i don't use the TBolt on Ext-Ref , won't i get hit by having a > Std-Osc > >> installed ? > >> > >> I have a GPS Antenna-Splitter , another TBolt (just need to assemble the > >> PSU) , and also a X72 Rubi & a few FEI-5680's. > >> > >> So i could try those when i'm a bit more familiar with the Counter & > >> program. > >> > >> > >>> > >>> The default sampling time is 200mS > >>> > >> Ahhh ... Thanx now i know why my 1hr Trace Duration was so fast. > >> I assumed that Timelab would set the sampling interval written in > Timelab > >> via GPIB. But i'll just select 1sec manually. > >> > >> > >> > >>> So, to try your setup (TBolt on EXT REF and A): first inform the > TimeLab > >>> that you have 1 second frequency samples, then set the sampling time to > >>> 1 second (use FUNCTION button on the PM6680) and retry collecting > >>> data.In this case the predicted uncertainty is 0.005 (5E-10) and sholud > >>> average out to 5E-13 in 1000 seconds taking into consideratin that the > >>> full 12 digit resolution is available at the PM6680 GPIB (that is, the > >>> GPIB has more digits than the display can show, see page 11-18 of the > >>> manual). > >>> > >> > >> I will try this now , and i
Re: [time-nuts] Is Timelab with a Prologix-Eth and a PM6680 - working ?
> Ahhh ... Thanx now i know why my 1hr Trace Duration was so fast. > I assumed that Timelab would set the sampling interval written in Timelab > via GPIB. But i'll just select 1sec manually. That can be a bit confusing. The TimeLab drivers for GPIB counters don't attempt to program the counter in any respect, beyond perhaps turning off continuous acquisition so that the program can fetch readings synchronously. The program may also disable various statistical features that are known to interfere with reading a stream of simple TI or frequency measurements. But for the most part, TimeLab expects you to configure the counter manually, using whatever settings and parameters you want. Then you have to fill in the acquisition dialog to tell the program what you're doing. This lazy approach violates the most commonly recommended GPIB programming practice, where the program begins by resetting the instrument to its default state and then programs all modes and settings of interest. But it's the only way I can afford the time to support lots of different counter models, most of which I don't own. :) For counters in talk-only mode, the acquisition driver can't program the instrument at all, so the above is doubly true. In the specific case of the Trace Duration field, TimeLab will estimate the rate at which readings arrive from the counter if you press the "Monitor" button and wait a bit for the estimate to settle down. If it doesn't seem to be converging on the right rate, try toggling the Monitor button off and on. Otherwise, if you don't use the Monitor feature, you will have to enter the trigger rate manually. > I will try this now , and i assume i should then select Frequency in the > Data Type - In TimeLab , as i don't use A->B measurements .. Or ? Most TICs exhibit some dead time between GPIB readings in frequency-count mode. For instance, if you use an HP 5370B in FREQ mode, you'll see something like 1.1 seconds between readings, instead of the 1-second gate time you may have selected at the counter's front panel. Not the end of the world, but something to keep in mind when deciding whether you want to capture TI or frequency data. That being said, when I use my 5370B, I usually use frequency mode with a 1-second gate time. It's quicker and much less error-prone to set up. The quantization/jitter floor isn't that much worse than what a TI measurement can achieve, I don't have to worry about whether the START and STOP sources are stable and close enough in frequency to avoid undersampling phase wraps, and the resulting data quality is OK for many purposes. This will be true for most other counters as well. When you are first getting started with TimeLab, I'd recommend sticking with frequency readings until you're more familiar with the overall process. Once frequency readings are being collected and displayed properly, you can consider switching to TI mode when appropriate. Finally, the Prologix adapters should work well with the various GPIB counter options in TimeLab, but especially with the Ethernet adapter, you may not want to use trigger rates faster than 1 Hz, at least not at first. As you get closer to 10 readings per second, the likelihood increases that the combination of the Ethernet adapter and the TimeLab driver won't keep up. The firmware in the Ethernet adapter doesn't handle these overrun conditions very well, and may lock up hard enough to require a power-cycle to recover. When I use a GPIB-Ethernet dongle with my 5370B, I usually keep the display rate control near 12 o'clock to limit the trigger rate to 4-5 per second. That's very reliable in my experience, but 10+ readings per second is not. -- john, KE5FX www.miles.io ___ 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.
