Re: [time-nuts] LPRO101 orientation vs lock
Hi Rb's die if you let them get to warm. If it's in a plugin sized enclosure count on a pretty good fan. Bob On Sep 16, 2010, at 3:57 PM, d.sei...@comcast.net wrote: > > > Hi Bob- > > > > I don't have the LPRO in a plugin, but I had considered it, and was wondering > if any of those that had built one had thermal and/or lock issues. > > > > Re the sun in our valley... not this year! My tomatoes just started really > producing and my squash and zucchini still haven't even flowered. That has > NEVER happened to me before. A very odd year weather-wise! > > > > Dave > - Original Message - > From: k6...@comcast.net > To: time-nuts@febo.com > Sent: Thursday, September 16, 2010 8:07:19 AM > Subject: Re: [time-nuts] LPRO101 orientation vs lock > > I assume you mean Tektronix TM5xx or 5xxx modules. > > I haven't seen an LPRO plugin, but considered doing one for my TM506 rack. My > conclusion was that I couldn't get rid of enough heat without cutting custom > fins for the LPRO. > > Recall that the physics package in the LPRO is the biggest source of heat, > and looking at the unit with the connector facing you and on the left, the > physics package is along the right side toward the rear of the unit. I > decided the way to mount the LPRO if I had to go vertical was with the > physics package closest to the top, to minimize the components that got > baked. (I welcome recalibration of this opinion from more knowledgeable > sources!) > > If I could cut fins for the new "top" edge, as well as a good plate for the > bottom, and some fans, i might be able to get rid of enough heat to make it > work. I considered mounting the LPRO to the rear of the module connectors, in > the area containing the linear power supply components. > > I reconsidered on recalling admonishments in the LPRO docs and on this list > that cesiums do not like magnetic fields! Mounting the unit next to large > power transformers wouldn't seem to be suck a good idea... > > You might have better luck running it in a TM5006 rack, as they have much > better cooling and airflow (a reason to get rid of that 506 and pick up a > 5006!). > > I've had good results with my LPRO mounted on a half inch plate of T6061 > aluminum and an old AMD heatsink+fan mounted above the physics package, held > in place with arctic silver heat transfer compound and spring-loaded wire > clips going to the plate. I've been meaning to run noise studies to see if > the fan causes any problems (vis a vis mag fields). > > Since I expect to be using the LPRO only occasionally, I've been trying to > talk my son into making me a steampunk-themed case, something like rosewood > with brass corners and detailing... > > Cheers and 73 -- Bob K6RTM in sunny silicon valley > > > On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > >> I got one of the ebay LPRO-101s about 6 months ago and played with it for a >> while, but had problems maintaining a lock. First of all, it has a heat sink >> bolted to the bottom that is just a little larger than the LPRO itself, >> including being about 1.25" thick( 1" fins). Typical frequency when locked >> is 10,000,000.007 on a 5360A clocked by a Z3801A. >> >> >> Both then and now, it takes about 45 seconds to lock from cold, and will >> stay locked for about 45 minutes. I found that in the position with the heat >> sink on the bottom will stay locked the longest (up to a few days), but then >> it becomes intermittent. Other positions will lock for a while, but bottom >> down always works the longest. >> >> >> For those of you who employed these in TM5xx or similar plugins, did you >> have lock issues? Is my unit just old? >> >> >> Dave >> ___ >> 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 > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > End of time-nuts Digest, Vol 74, Issue 77 > * > ___ > 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] LPRO101 orientation vs lock
Nice to know I'm not the only one who has had this idea.
My thinking was to use a laptop supply plugged into a socket on the
back of the TM5006 and route volts down a pair on the back-plane to
modules that need continuous power. Drive the GPSDO and ovens on the
modules that have them.
And use a couple of other pairs for USB/serial, put a USB<->GPIB and
USB hub in the empty space back around the power supply. Poof, modern
instrument. More or less. :)
Have also considered using a TM50{2,3,4} as an enclosure/basis for a
rover transverter setup.
Bob
KI2L
On Thu, Sep 16, 2010 at 4:29 PM, wrote:
> It seems like it would be very tight in a single plug-in, if it even fits. A
> dual PI would certainly work though.
>
> Also, as someone pointed out, the TM-500 series may not have the power and
> cooling available. I have. TM-5006 chassis that would certainly do the job in
> both regards, but that's the last thing I would want running 24/7 in my
> shop...
>
> My LPRO found a spot in an old HP bench voltmeter chassis, and runs from a
> recycled laptop power supply (that way, the heat from the supply is not
> dissipated in the box). The installation is not complete, but I intend to
> install a small computer fan to keep the air moving through holes in the
> chassis.
>
> I will then use a modified T-Bolt Monitor to monitor the parameters from the
> LPRO, and the temperature via a front panel display.
>
> Didier KO4BB
>
> Sent from my Verizon Wireless BlackBerry
>
> -Original Message-
> From: d.sei...@comcast.net
> Sender: time-nuts-boun...@febo.com
> Date: Thu, 16 Sep 2010 19:57:09
> To: Discussion of precise time and frequency measurement
> Reply-To: Discussion of precise time and frequency measurement
>
> Subject: Re: [time-nuts] LPRO101 orientation vs lock
>
>
>
> Hi Bob-
>
>
>
> I don't have the LPRO in a plugin, but I had considered it, and was wondering
> if any of those that had built one had thermal and/or lock issues.
>
>
>
> Re the sun in our valley... not this year! My tomatoes just started really
> producing and my squash and zucchini still haven't even flowered. That has
> NEVER happened to me before. A very odd year weather-wise!
>
>
>
> Dave
> ----- Original Message -
> From: k6...@comcast.net
> To: time-nuts@febo.com
> Sent: Thursday, September 16, 2010 8:07:19 AM
> Subject: Re: [time-nuts] LPRO101 orientation vs lock
>
> I assume you mean Tektronix TM5xx or 5xxx modules.
>
> I haven't seen an LPRO plugin, but considered doing one for my TM506 rack. My
> conclusion was that I couldn't get rid of enough heat without cutting custom
> fins for the LPRO.
>
> Recall that the physics package in the LPRO is the biggest source of heat,
> and looking at the unit with the connector facing you and on the left, the
> physics package is along the right side toward the rear of the unit. I
> decided the way to mount the LPRO if I had to go vertical was with the
> physics package closest to the top, to minimize the components that got
> baked. (I welcome recalibration of this opinion from more knowledgeable
> sources!)
>
> If I could cut fins for the new "top" edge, as well as a good plate for the
> bottom, and some fans, i might be able to get rid of enough heat to make it
> work. I considered mounting the LPRO to the rear of the module connectors, in
> the area containing the linear power supply components.
>
> I reconsidered on recalling admonishments in the LPRO docs and on this list
> that cesiums do not like magnetic fields! Mounting the unit next to large
> power transformers wouldn't seem to be suck a good idea...
>
> You might have better luck running it in a TM5006 rack, as they have much
> better cooling and airflow (a reason to get rid of that 506 and pick up a
> 5006!).
>
> I've had good results with my LPRO mounted on a half inch plate of T6061
> aluminum and an old AMD heatsink+fan mounted above the physics package, held
> in place with arctic silver heat transfer compound and spring-loaded wire
> clips going to the plate. I've been meaning to run noise studies to see if
> the fan causes any problems (vis a vis mag fields).
>
> Since I expect to be using the LPRO only occasionally, I've been trying to
> talk my son into making me a steampunk-themed case, something like rosewood
> with brass corners and detailing...
>
> Cheers and 73 -- Bob K6RTM in sunny silicon valley
>
>
> On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote:
>
>> I got one of the ebay LPRO-101s about 6 months ago and played with it for a
>> while, but had problems maintaining a lock. First of all, it has a h
Re: [time-nuts] LPRO101 orientation vs lock
It seems like it would be very tight in a single plug-in, if it even fits. A dual PI would certainly work though. Also, as someone pointed out, the TM-500 series may not have the power and cooling available. I have. TM-5006 chassis that would certainly do the job in both regards, but that's the last thing I would want running 24/7 in my shop... My LPRO found a spot in an old HP bench voltmeter chassis, and runs from a recycled laptop power supply (that way, the heat from the supply is not dissipated in the box). The installation is not complete, but I intend to install a small computer fan to keep the air moving through holes in the chassis. I will then use a modified T-Bolt Monitor to monitor the parameters from the LPRO, and the temperature via a front panel display. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: d.sei...@comcast.net Sender: time-nuts-boun...@febo.com Date: Thu, 16 Sep 2010 19:57:09 To: Discussion of precise time and frequency measurement Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] LPRO101 orientation vs lock Hi Bob- I don't have the LPRO in a plugin, but I had considered it, and was wondering if any of those that had built one had thermal and/or lock issues. Re the sun in our valley... not this year! My tomatoes just started really producing and my squash and zucchini still haven't even flowered. That has NEVER happened to me before. A very odd year weather-wise! Dave - Original Message - From: k6...@comcast.net To: time-nuts@febo.com Sent: Thursday, September 16, 2010 8:07:19 AM Subject: Re: [time-nuts] LPRO101 orientation vs lock I assume you mean Tektronix TM5xx or 5xxx modules. I haven't seen an LPRO plugin, but considered doing one for my TM506 rack. My conclusion was that I couldn't get rid of enough heat without cutting custom fins for the LPRO. Recall that the physics package in the LPRO is the biggest source of heat, and looking at the unit with the connector facing you and on the left, the physics package is along the right side toward the rear of the unit. I decided the way to mount the LPRO if I had to go vertical was with the physics package closest to the top, to minimize the components that got baked. (I welcome recalibration of this opinion from more knowledgeable sources!) If I could cut fins for the new "top" edge, as well as a good plate for the bottom, and some fans, i might be able to get rid of enough heat to make it work. I considered mounting the LPRO to the rear of the module connectors, in the area containing the linear power supply components. I reconsidered on recalling admonishments in the LPRO docs and on this list that cesiums do not like magnetic fields! Mounting the unit next to large power transformers wouldn't seem to be suck a good idea... You might have better luck running it in a TM5006 rack, as they have much better cooling and airflow (a reason to get rid of that 506 and pick up a 5006!). I've had good results with my LPRO mounted on a half inch plate of T6061 aluminum and an old AMD heatsink+fan mounted above the physics package, held in place with arctic silver heat transfer compound and spring-loaded wire clips going to the plate. I've been meaning to run noise studies to see if the fan causes any problems (vis a vis mag fields). Since I expect to be using the LPRO only occasionally, I've been trying to talk my son into making me a steampunk-themed case, something like rosewood with brass corners and detailing... Cheers and 73 -- Bob K6RTM in sunny silicon valley On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > I got one of the ebay LPRO-101s about 6 months ago and played with it for a > while, but had problems maintaining a lock. First of all, it has a heat sink > bolted to the bottom that is just a little larger than the LPRO itself, > including being about 1.25" thick( 1" fins). Typical frequency when locked is > 10,000,000.007 on a 5360A clocked by a Z3801A. > > > Both then and now, it takes about 45 seconds to lock from cold, and will stay > locked for about 45 minutes. I found that in the position with the heat sink > on the bottom will stay locked the longest (up to a few days), but then it > becomes intermittent. Other positions will lock for a while, but bottom down > always works the longest. > > > For those of you who employed these in TM5xx or similar plugins, did you have > lock issues? Is my unit just old? > > > Dave > ___ > 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] LPRO101 orientation vs lock
Hi Bob- I don't have the LPRO in a plugin, but I had considered it, and was wondering if any of those that had built one had thermal and/or lock issues. Re the sun in our valley... not this year! My tomatoes just started really producing and my squash and zucchini still haven't even flowered. That has NEVER happened to me before. A very odd year weather-wise! Dave - Original Message - From: k6...@comcast.net To: time-nuts@febo.com Sent: Thursday, September 16, 2010 8:07:19 AM Subject: Re: [time-nuts] LPRO101 orientation vs lock I assume you mean Tektronix TM5xx or 5xxx modules. I haven't seen an LPRO plugin, but considered doing one for my TM506 rack. My conclusion was that I couldn't get rid of enough heat without cutting custom fins for the LPRO. Recall that the physics package in the LPRO is the biggest source of heat, and looking at the unit with the connector facing you and on the left, the physics package is along the right side toward the rear of the unit. I decided the way to mount the LPRO if I had to go vertical was with the physics package closest to the top, to minimize the components that got baked. (I welcome recalibration of this opinion from more knowledgeable sources!) If I could cut fins for the new "top" edge, as well as a good plate for the bottom, and some fans, i might be able to get rid of enough heat to make it work. I considered mounting the LPRO to the rear of the module connectors, in the area containing the linear power supply components. I reconsidered on recalling admonishments in the LPRO docs and on this list that cesiums do not like magnetic fields! Mounting the unit next to large power transformers wouldn't seem to be suck a good idea... You might have better luck running it in a TM5006 rack, as they have much better cooling and airflow (a reason to get rid of that 506 and pick up a 5006!). I've had good results with my LPRO mounted on a half inch plate of T6061 aluminum and an old AMD heatsink+fan mounted above the physics package, held in place with arctic silver heat transfer compound and spring-loaded wire clips going to the plate. I've been meaning to run noise studies to see if the fan causes any problems (vis a vis mag fields). Since I expect to be using the LPRO only occasionally, I've been trying to talk my son into making me a steampunk-themed case, something like rosewood with brass corners and detailing... Cheers and 73 -- Bob K6RTM in sunny silicon valley On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > I got one of the ebay LPRO-101s about 6 months ago and played with it for a > while, but had problems maintaining a lock. First of all, it has a heat sink > bolted to the bottom that is just a little larger than the LPRO itself, > including being about 1.25" thick( 1" fins). Typical frequency when locked is > 10,000,000.007 on a 5360A clocked by a Z3801A. > > > Both then and now, it takes about 45 seconds to lock from cold, and will stay > locked for about 45 minutes. I found that in the position with the heat sink > on the bottom will stay locked the longest (up to a few days), but then it > becomes intermittent. Other positions will lock for a while, but bottom down > always works the longest. > > > For those of you who employed these in TM5xx or similar plugins, did you have > lock issues? Is my unit just old? > > > Dave > ___ > 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 74, Issue 77 * ___ 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] LPRO101 orientation vs lock
If you find a good source for the prototype kits, by all means, let me know. I've been gutting cheap/dead modules for the enclosures. A project I've been considering is putting a T'bolt into one just to send 1pps and 10mhz down the backplane. BTW, there is a yahoo group for TM500/5000 series gear. Not much traffic, but it is there. http://tech.groups.yahoo.com/group/tek500/ On Thu, Sep 16, 2010 at 11:19 AM, wrote: > Aha! Once again, Google is your friend -- > > http://www.slack.com/images/TE/EfratomPTB-100.jpg > > shows the Efratom Rubidium module, and it's a double-width unit. That gives > plenty of room to mount the module horizontally, and plenty of room above and > below for fins and fans. > > When I get my time machine working, one of the things I want to go back and > stock up on are Tek 5xx prototyping kits. The single-width kits are rare > enough these days (and expensive), but the double-width ones are pure > unobtanium! > > Bob K6RTM > > On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > >> I got one of the ebay LPRO-101s about 6 months ago and played with it for a >> while, but had problems maintaining a lock. First of all, it has a heat sink >> bolted to the bottom that is just a little larger than the LPRO itself, >> including being about 1.25" thick( 1" fins). Typical frequency when locked >> is 10,000,000.007 on a 5360A clocked by a Z3801A. >> >> >> Both then and now, it takes about 45 seconds to lock from cold, and will >> stay locked for about 45 minutes. I found that in the position with the heat >> sink on the bottom will stay locked the longest (up to a few days), but then >> it becomes intermittent. Other positions will lock for a while, but bottom >> down always works the longest. >> >> >> For those of you who employed these in TM5xx or similar plugins, did you >> have lock issues? Is my unit just old? >> >> >> Dave > > ___ > 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] LPRO101 orientation vs lock
Aha! Once again, Google is your friend -- http://www.slack.com/images/TE/EfratomPTB-100.jpg shows the Efratom Rubidium module, and it's a double-width unit. That gives plenty of room to mount the module horizontally, and plenty of room above and below for fins and fans. When I get my time machine working, one of the things I want to go back and stock up on are Tek 5xx prototyping kits. The single-width kits are rare enough these days (and expensive), but the double-width ones are pure unobtanium! Bob K6RTM On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > I got one of the ebay LPRO-101s about 6 months ago and played with it for a > while, but had problems maintaining a lock. First of all, it has a heat sink > bolted to the bottom that is just a little larger than the LPRO itself, > including being about 1.25" thick( 1" fins). Typical frequency when locked is > 10,000,000.007 on a 5360A clocked by a Z3801A. > > > Both then and now, it takes about 45 seconds to lock from cold, and will stay > locked for about 45 minutes. I found that in the position with the heat sink > on the bottom will stay locked the longest (up to a few days), but then it > becomes intermittent. Other positions will lock for a while, but bottom down > always works the longest. > > > For those of you who employed these in TM5xx or similar plugins, did you have > lock issues? Is my unit just old? > > > Dave ___ 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] LPRO101 orientation vs lock
I assume you mean Tektronix TM5xx or 5xxx modules. I haven't seen an LPRO plugin, but considered doing one for my TM506 rack. My conclusion was that I couldn't get rid of enough heat without cutting custom fins for the LPRO. Recall that the physics package in the LPRO is the biggest source of heat, and looking at the unit with the connector facing you and on the left, the physics package is along the right side toward the rear of the unit. I decided the way to mount the LPRO if I had to go vertical was with the physics package closest to the top, to minimize the components that got baked. (I welcome recalibration of this opinion from more knowledgeable sources!) If I could cut fins for the new "top" edge, as well as a good plate for the bottom, and some fans, i might be able to get rid of enough heat to make it work. I considered mounting the LPRO to the rear of the module connectors, in the area containing the linear power supply components. I reconsidered on recalling admonishments in the LPRO docs and on this list that cesiums do not like magnetic fields! Mounting the unit next to large power transformers wouldn't seem to be suck a good idea... You might have better luck running it in a TM5006 rack, as they have much better cooling and airflow (a reason to get rid of that 506 and pick up a 5006!). I've had good results with my LPRO mounted on a half inch plate of T6061 aluminum and an old AMD heatsink+fan mounted above the physics package, held in place with arctic silver heat transfer compound and spring-loaded wire clips going to the plate. I've been meaning to run noise studies to see if the fan causes any problems (vis a vis mag fields). Since I expect to be using the LPRO only occasionally, I've been trying to talk my son into making me a steampunk-themed case, something like rosewood with brass corners and detailing... Cheers and 73 -- Bob K6RTM in sunny silicon valley On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > I got one of the ebay LPRO-101s about 6 months ago and played with it for a > while, but had problems maintaining a lock. First of all, it has a heat sink > bolted to the bottom that is just a little larger than the LPRO itself, > including being about 1.25" thick( 1" fins). Typical frequency when locked is > 10,000,000.007 on a 5360A clocked by a Z3801A. > > > Both then and now, it takes about 45 seconds to lock from cold, and will stay > locked for about 45 minutes. I found that in the position with the heat sink > on the bottom will stay locked the longest (up to a few days), but then it > becomes intermittent. Other positions will lock for a while, but bottom down > always works the longest. > > > For those of you who employed these in TM5xx or similar plugins, did you have > lock issues? Is my unit just old? > > > Dave > ___ > 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 74, Issue 77 * ___ 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] LPRO101 orientation vs lock
Hi First thing would be a touch test on the heat sink. It should be warm, but not to hot to touch. Heat sink down should be hotter than vertical. That assumes there's no moving air. Next, start watching the VCXO voltage. Normal readings are around 5 to 7 volts. I'd bet you are running closer to the rails. If so a VCXO repair may help. Past that it gets complex. The end of life on a Rb is indeed loss of lock... Bob On Sep 16, 2010, at 2:51 AM, d.sei...@comcast.net wrote: > I got one of the ebay LPRO-101s about 6 months ago and played with it for a > while, but had problems maintaining a lock. First of all, it has a heat sink > bolted to the bottom that is just a little larger than the LPRO itself, > including being about 1.25" thick( 1" fins). Typical frequency when locked is > 10,000,000.007 on a 5360A clocked by a Z3801A. > > > Both then and now, it takes about 45 seconds to lock from cold, and will stay > locked for about 45 minutes. I found that in the position with the heat sink > on the bottom will stay locked the longest (up to a few days), but then it > becomes intermittent. Other positions will lock for a while, but bottom down > always works the longest. > > > For those of you who employed these in TM5xx or similar plugins, did you have > lock issues? Is my unit just old? > > > Dave > ___ > 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] LPRO101 orientation vs lock
d.seiter-"...Both then and now, it takes about 45 seconds to lock from cold, and will stay locked for about 45 minutes" ++ I'm surprised that it locks in 45 seconds, I would expect it to take about 3-4 minutes. All the units I have lock in 3-5 minutes if they are good, or longer if they are nearing end of life. The manual also specifies 3-4 minutes to lock. As to the heat sink, that may be a problem. Check to see that the baseplate temperature does not exceed 70 degrees C. This could be your problem. The manual states: "When thermal control is lost the result is a large rate of change of frequency versus temperature. As the baseplate temperature increases the unit will eventually lose lock." -Arthur ___ 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] LPRO101 orientation vs lock
Hi, there are two obvious causes of lost lock, wandering off beyond the range of the voltage controlled crystal local oscillator, not an OXCO, which is swept through the atomic response frequency, and the failure of the rubidium lamp at the end of its life. The oscillator sweeping voltage (pin 9) has limits and if the correct frequency is not in the range lock is not possible. If the VCXO has drifted it may be possible to add/remove a tiny amount of capacitance from the oscillator circuit to get it in range. The rubidium lamp voltage (pin 5) is between 3 (low) and 14 volts, at the end of the lamp life it goes low. This is all from my memory, the detail is in the User's guide and integration guidelines. cheers, Neville Michie On 16/09/2010, at 4:51 PM, d.sei...@comcast.net wrote: I got one of the ebay LPRO-101s about 6 months ago and played with it for a while, but had problems maintaining a lock. First of all, it has a heat sink bolted to the bottom that is just a little larger than the LPRO itself, including being about 1.25" thick( 1" fins). Typical frequency when locked is 10,000,000.007 on a 5360A clocked by a Z3801A. Both then and now, it takes about 45 seconds to lock from cold, and will stay locked for about 45 minutes. I found that in the position with the heat sink on the bottom will stay locked the longest (up to a few days), but then it becomes intermittent. Other positions will lock for a while, but bottom down always works the longest. For those of you who employed these in TM5xx or similar plugins, did you have lock issues? Is my unit just old? Dave ___ 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] LPRO101 orientation vs lock
I got one of the ebay LPRO-101s about 6 months ago and played with it for a while, but had problems maintaining a lock. First of all, it has a heat sink bolted to the bottom that is just a little larger than the LPRO itself, including being about 1.25" thick( 1" fins). Typical frequency when locked is 10,000,000.007 on a 5360A clocked by a Z3801A. Both then and now, it takes about 45 seconds to lock from cold, and will stay locked for about 45 minutes. I found that in the position with the heat sink on the bottom will stay locked the longest (up to a few days), but then it becomes intermittent. Other positions will lock for a while, but bottom down always works the longest. For those of you who employed these in TM5xx or similar plugins, did you have lock issues? Is my unit just old? Dave ___ 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.
