Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Replied off-list but suggestions welcome. On Sun, Mar 31, 2019 at 6:00 PM Mod Mix wrote: > Hi Adrian, > sorry for cantacting you directly... > I've got a pair of KS-24361 showing now the red FAULT led on just after > applying power. > As I don't know much about these electronics: could you pls give me an > indication where to find a possibly failed tant? > Thank you in advance > Ulli > > > Am 24.02.2019 um 15:07 schrieb Adrian Godwin: > > Just to sneak that back on-topic .. the most recent tant failure I had > was > > in a KS-24361. It was after the dc-dc converter so it didn't look like a > > short to the input - it just increased the current draw. Running off a > > cheap laptop supply, which overheated and melted instead of shutting down > > or blowing a fuse. It took out the breaker for the whole ring main. > > > > Replacing the tant was the only action necessary for the KS-24361 itself. > > No other internal damage. > ---snip--- > > ___ > 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Hi Adrian, sorry for cantacting you directly... I've got a pair of KS-24361 showing now the red FAULT led on just after applying power. As I don't know much about these electronics: could you pls give me an indication where to find a possibly failed tant? Thank you in advance Ulli Am 24.02.2019 um 15:07 schrieb Adrian Godwin: Just to sneak that back on-topic .. the most recent tant failure I had was in a KS-24361. It was after the dc-dc converter so it didn't look like a short to the input - it just increased the current draw. Running off a cheap laptop supply, which overheated and melted instead of shutting down or blowing a fuse. It took out the breaker for the whole ring main. Replacing the tant was the only action necessary for the KS-24361 itself. No other internal damage. ---snip--- ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Hi Well …. ummm …. errr …. it turns out that there *are* (or were) papers published on the topic that are “well known” in the … e …. space community and pop right out of the stack of papers that the guys from …. errr …. a well known space outfit in California bring with them …. The issue is that below some magic percentage of the rated voltage, the dielectric may try to re-form. When it does, the outcome is a bit unpredictable. As I recall it applies both to tantalum and aluminum parts. There are different factors for the two types. Keep in mind this all came up in a meeting in the mid 1990’s ….memory is only just so good ... Bob > On Feb 25, 2019, at 9:56 AM, jimlux wrote: > > On 2/25/19 5:48 AM, Bob kb8tq wrote: >> Hi >> Indeed there is both a minimum and a maximum working voltage for a properly >> derated electrolytic >> capacitor. We found that out in the middle of a design review when the >> customer’s team brought it >> up … (much to our surprise). >> Bob > > > The Cornell Dubilier app guide doesn't seem to mention it. > http://www.cde.com/resources/catalogs/AEappGUIDE.pdf > > NAVSEA derating guidelines make no mention of it: > https://www.navsea.navy.mil/Portals/103/Documents/NSWC_Crane/SD-18/PDFs/Products/Capacitors/CapacitorsDeratingRevB.pdf > > They're both appear to be focused on essentially setting a lower voltage as a > thermal consideration, and not on a "giving you more margin to failure > voltage". > > https://www.illinoiscapacitor.com/pdf/Papers/reliability_of_capacitors_general.pdf > > says you only get a max of twice rated life by derating. Maybe that's > because of the "reforming of the dielectric to a thinner layer".. > > This is a compendium from 1981 of all sorts of capacitor information but > doesn't seem to address derating. > https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810017835.pdf > > > https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003309.pdf has a > lot of info on wet slug tantalums.. > > > > >>> On Feb 25, 2019, at 1:48 AM, Poul-Henning Kamp wrote: >>> >>> >>> In message >>> , Dana >>> Whitlow writes: >>> This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? >>> >>> I've always wondered that myself, and found very little documentation or >>> wisdom available. >>> >>> As I understand it, even very brief voltage spikes must be kept under the >>> rated voltage, so overrating would buy some transient durability, but >>> other than that... >>> >>> -- >>> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >>> p...@freebsd.org | TCP/IP since RFC 956 >>> FreeBSD committer | BSD since 4.3-tahoe >>> Never attribute to malice what can adequately be explained by incompetence. >>> >>> ___ >>> 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
In message <1f48decf-dee6-220f-f7ce-948642724...@rubidium.se>, Magnus Danielson writes: >The trouble with aluminium electrolytics is [...] Thanks for proving the exact point I made in my email yesterday. Now please go read it, because it contains some important details :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Hi, On 2019-02-25 07:48, Poul-Henning Kamp wrote: In message , Dana Whitlow writes: This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? I've always wondered that myself, and found very little documentation or wisdom available. As I understand it, even very brief voltage spikes must be kept under the rated voltage, so overrating would buy some transient durability, but other than that... The trouble with aluminium electrolytics is that if not voltaged is applied, the oxide layer slowly breaks down. This is why the capacitors is stored charged and needs to have slowly increased voltage for the oxide layer to rebuild. If too high voltage is applied it breaks through. Now, over-rating could potentially not work very well if not operated at high enough voltage. I don't recall for sure the reference for this, but I think some of it was out of AT Reliability manual. I'm too far away on travels from my library to check on details. It's also a concern with boat-anchor equipment. Direct full-voltage power-up can make the caps blow in the PSU. Cheers, Magnus ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
On 2/25/19 5:48 AM, Bob kb8tq wrote: Hi Indeed there is both a minimum and a maximum working voltage for a properly derated electrolytic capacitor. We found that out in the middle of a design review when the customer’s team brought it up … (much to our surprise). Bob The Cornell Dubilier app guide doesn't seem to mention it. http://www.cde.com/resources/catalogs/AEappGUIDE.pdf NAVSEA derating guidelines make no mention of it: https://www.navsea.navy.mil/Portals/103/Documents/NSWC_Crane/SD-18/PDFs/Products/Capacitors/CapacitorsDeratingRevB.pdf They're both appear to be focused on essentially setting a lower voltage as a thermal consideration, and not on a "giving you more margin to failure voltage". https://www.illinoiscapacitor.com/pdf/Papers/reliability_of_capacitors_general.pdf says you only get a max of twice rated life by derating. Maybe that's because of the "reforming of the dielectric to a thinner layer".. This is a compendium from 1981 of all sorts of capacitor information but doesn't seem to address derating. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810017835.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003309.pdf has a lot of info on wet slug tantalums.. On Feb 25, 2019, at 1:48 AM, Poul-Henning Kamp wrote: In message , Dana Whitlow writes: This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? I've always wondered that myself, and found very little documentation or wisdom available. As I understand it, even very brief voltage spikes must be kept under the rated voltage, so overrating would buy some transient durability, but other than that... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Hi Indeed there is both a minimum and a maximum working voltage for a properly derated electrolytic capacitor. We found that out in the middle of a design review when the customer’s team brought it up … (much to our surprise). Bob > On Feb 25, 2019, at 1:48 AM, Poul-Henning Kamp wrote: > > > In message > , Dana > Whitlow writes: > >> This would seem to imply that purposely overrating a 'lyt is pretty >> pointless. >> >> Any comments on this notion? > > I've always wondered that myself, and found very little documentation or > wisdom available. > > As I understand it, even very brief voltage spikes must be kept under the > rated voltage, so overrating would buy some transient durability, but > other than that... > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
I do not know, if the brake down voltage decreases if the electrolyte capacitor is used well bellow the original rated voltage, but I know from experience, that if you cautiously and slowly increase the voltage across the capacitor it will work at higher than the rated voltage, but with reduced capacitance. Alex On 2/24/2019 7:08 PM, Dana Whitlow wrote: I remember often reading that if you run a 'lyt at a voltage much reduced from its rating, the oxide layer would get thinner over time so that in the end, the effective rating of the capacitor was about what you had been running it at. This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? Dana On Sun, Feb 24, 2019 at 7:01 PM Gerhard Hoffmann wrote: Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist: yet they got a pass and became SOP. The R lab manager at Santa Clara Division famously said "no customer chooses HP products because they have great power supplies." G.. My HP16500C has a defective PS and my 4274A RLC bridge had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke! I re-caped the bridge, it took me a day on the DIgikey site to find replacements. I had to use substantially larger voltages to make them fit mechanically. But that is a good thing. cheers, Gerhard ___ 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. --- This email has been checked for viruses by AVG. https://www.avg.com ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
In message , Dana Whitlow writes: >This would seem to imply that purposely overrating a 'lyt is pretty pointless. > >Any comments on this notion? I've always wondered that myself, and found very little documentation or wisdom available. As I understand it, even very brief voltage spikes must be kept under the rated voltage, so overrating would buy some transient durability, but other than that... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
I remember often reading that if you run a 'lyt at a voltage much reduced from its rating, the oxide layer would get thinner over time so that in the end, the effective rating of the capacitor was about what you had been running it at. This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? Dana On Sun, Feb 24, 2019 at 7:01 PM Gerhard Hoffmann wrote: > > Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist: > > > > yet they got a pass and became SOP. The R lab manager > > at Santa Clara Division famously said "no customer chooses > > HP products because they have great power supplies." > > > G.. My HP16500C has a defective PS and my 4274A RLC bridge > > had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke! > > I re-caped the bridge, it took me a day on the DIgikey site to find > replacements. > > I had to use substantially larger voltages to make them fit mechanically. > > But that is a good thing. > > cheers, Gerhard > > > > ___ > 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist: yet they got a pass and became SOP. The R lab manager at Santa Clara Division famously said "no customer chooses HP products because they have great power supplies." G.. My HP16500C has a defective PS and my 4274A RLC bridge had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke! I re-caped the bridge, it took me a day on the DIgikey site to find replacements. I had to use substantially larger voltages to make them fit mechanically. But that is a good thing. cheers, Gerhard ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Adrian I had the same thing in the same unit. I guess the electrolytic's were bad in allowing hum through. The tants go Bang and burn. Though all caps can go bang I suspect. Paul WB8TSL On Sun, Feb 24, 2019 at 5:04 PM Adrian Godwin wrote: > Just to sneak that back on-topic .. the most recent tant failure I had was > in a KS-24361. It was after the dc-dc converter so it didn't look like a > short to the input - it just increased the current draw. Running off a > cheap laptop supply, which overheated and melted instead of shutting down > or blowing a fuse. It took out the breaker for the whole ring main. > > Replacing the tant was the only action necessary for the KS-24361 itself. > No other internal damage. > > On Sun, Feb 24, 2019 at 2:02 PM Adrian Godwin wrote: > > > I think I've had as many shorted-out tants as dried-out electrolytics. > > It's just that they appear in 80s gear instead of 60s. Then there was the > > flood of high-esr electrolytics from when - early 2000s ? > > > > > > On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) < > > hugh.r...@hp.com> wrote: > > > >> Several people have asked about the Len Cutler ban on Aluminum > >> Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist > could > >> shed more light on this too. The legend of the ban was passed along to > >> me, perhaps by Lou Mueller, who liked to tell stories of the old days. > In > >> 1985, we were not taking the ban literally. For example, the 2400uF > main > >> power supply filter capacitor was AL-Electrolytic, as were a few other > >> smaller capacitors on the power regulator. I sidestepped the capacitor > >> issues on my simple battery charger by not having a filter cap after the > >> transformer/full-wave-bridge, and just used 120 Hz pulses, since the > >> battery didn't care about DC vs. pulsed DC. (I thought it was pretty > >> clever to leave out the main filter cap.) Where possible, Tantalum > >> capacitors were used.For the few places where AL caps were used, > they > >> were heavily de-rated, operating at 50% of rated voltage for example. > >> > >> As one reader pointed out, back in the 1965 when the 5060A was > developed, > >> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I > >> worked on the 5061B. > >> > >> > >> From: time-nuts On Behalf Of Rice, > >> Hugh (IPH Writing Systems) > >> Sent: Saturday, February 23, 2019 8:49 PM > >> To: time-nuts@lists.febo.com > >> Subject: [time-nuts] HP Stories: An architectural view of the HP > >> 5060/5061 and awkward oscillator adjustments. > >> > >> Hello Time-Nuts, > >> > >> Stuff deleted . > >> > >> > >> It was fantastically reliable. Only linear power circuits, with robust > >> heat sinking of all power devices. The legendary Len Cutler ban on > aluminum > >> electrolytic capacitors. 5060s were still in use in 1985, after 20 > years of > >> constant operation. Likewise, 5061As were abundant in time standards for > >> 25+ years until they were replaced by the 5071A in the 1990s. > >> > >> ___ > >> 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
In message , Adrian Godwin writes: >I think I've had as many shorted-out tants as dried-out electrolytics. I doubt Len worried about dry-out, he was worried about shorts. A lot of people failed, and still fail, to realize that tube-voltage electrolytics are an entirely different kettle of fish from semiconductor-voltage electrolytics. The crucial difference is that in an unpowered high-voltage 'lyt the oxidelayer will degenerate over time, and then when you apply power again, it shorts through and bad things happen. This is where the "Ramp up the voltage with a variac" thing comes from, As you raise the voltage slowly, the oxide layer has time to reform to the required thickness for the the normal operating voltage[1]. Low voltage 'lyts do not have this problem, because the final layer of oxide is not going anywhere in benign chemical environments. Before that knowledge had rippled out through the EE community, 'lyts had got a reputation for being unreliable and prone to "unprovoked" venting and/or explosion, in particular in the "grew up with tubes" generation of EEs. There is no precise voltage to separate "high" and "low" voltage, it depends on the chemical formulation of the electrolyte, but as a rule of thumb 'lyts exposed to less than 50V do not short when powered up. Any 'lyt with a higher operating voltage should be ramped up slowly, if it has been without power for more than a year or two. Where this gets tricky is badly designed switch-modes, where the control circuit fails to start or latches up. Best advice there is to use a dummy load rather than Unobtanium if you can, or try find a way to disable the control circuit until you have ramped the 'lyt up. Drying out is an entirely different failure mode, caused mainly by high temperatures, either from ambient (Tubes) or self heating due to ripple-current in the ESR. Poul-Henning [1] I have tried to find out how slow one needs to ramp. People with chemical clue tell me that electrochemistry, is a matter of seconds. I round up to minutes. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Just to sneak that back on-topic .. the most recent tant failure I had was in a KS-24361. It was after the dc-dc converter so it didn't look like a short to the input - it just increased the current draw. Running off a cheap laptop supply, which overheated and melted instead of shutting down or blowing a fuse. It took out the breaker for the whole ring main. Replacing the tant was the only action necessary for the KS-24361 itself. No other internal damage. On Sun, Feb 24, 2019 at 2:02 PM Adrian Godwin wrote: > I think I've had as many shorted-out tants as dried-out electrolytics. > It's just that they appear in 80s gear instead of 60s. Then there was the > flood of high-esr electrolytics from when - early 2000s ? > > > On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) < > hugh.r...@hp.com> wrote: > >> Several people have asked about the Len Cutler ban on Aluminum >> Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist could >> shed more light on this too. The legend of the ban was passed along to >> me, perhaps by Lou Mueller, who liked to tell stories of the old days. In >> 1985, we were not taking the ban literally. For example, the 2400uF main >> power supply filter capacitor was AL-Electrolytic, as were a few other >> smaller capacitors on the power regulator. I sidestepped the capacitor >> issues on my simple battery charger by not having a filter cap after the >> transformer/full-wave-bridge, and just used 120 Hz pulses, since the >> battery didn't care about DC vs. pulsed DC. (I thought it was pretty >> clever to leave out the main filter cap.) Where possible, Tantalum >> capacitors were used.For the few places where AL caps were used, they >> were heavily de-rated, operating at 50% of rated voltage for example. >> >> As one reader pointed out, back in the 1965 when the 5060A was developed, >> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I >> worked on the 5061B. >> >> >> From: time-nuts On Behalf Of Rice, >> Hugh (IPH Writing Systems) >> Sent: Saturday, February 23, 2019 8:49 PM >> To: time-nuts@lists.febo.com >> Subject: [time-nuts] HP Stories: An architectural view of the HP >> 5060/5061 and awkward oscillator adjustments. >> >> Hello Time-Nuts, >> >> Stuff deleted . >> >> >> It was fantastically reliable. Only linear power circuits, with robust >> heat sinking of all power devices. The legendary Len Cutler ban on aluminum >> electrolytic capacitors. 5060s were still in use in 1985, after 20 years of >> constant operation. Likewise, 5061As were abundant in time standards for >> 25+ years until they were replaced by the 5071A in the 1990s. >> >> ___ >> 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
I think I've had as many shorted-out tants as dried-out electrolytics. It's just that they appear in 80s gear instead of 60s. Then there was the flood of high-esr electrolytics from when - early 2000s ? On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) < hugh.r...@hp.com> wrote: > Several people have asked about the Len Cutler ban on Aluminum > Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist could > shed more light on this too. The legend of the ban was passed along to > me, perhaps by Lou Mueller, who liked to tell stories of the old days. In > 1985, we were not taking the ban literally. For example, the 2400uF main > power supply filter capacitor was AL-Electrolytic, as were a few other > smaller capacitors on the power regulator. I sidestepped the capacitor > issues on my simple battery charger by not having a filter cap after the > transformer/full-wave-bridge, and just used 120 Hz pulses, since the > battery didn't care about DC vs. pulsed DC. (I thought it was pretty > clever to leave out the main filter cap.) Where possible, Tantalum > capacitors were used.For the few places where AL caps were used, they > were heavily de-rated, operating at 50% of rated voltage for example. > > As one reader pointed out, back in the 1965 when the 5060A was developed, > AL-Electrolytic caps were likely a lot less reliable than in 1985 when I > worked on the 5061B. > > > From: time-nuts On Behalf Of Rice, > Hugh (IPH Writing Systems) > Sent: Saturday, February 23, 2019 8:49 PM > To: time-nuts@lists.febo.com > Subject: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 > and awkward oscillator adjustments. > > Hello Time-Nuts, > > Stuff deleted . > > > It was fantastically reliable. Only linear power circuits, with robust > heat sinking of all power devices. The legendary Len Cutler ban on aluminum > electrolytic capacitors. 5060s were still in use in 1985, after 20 years of > constant operation. Likewise, 5061As were abundant in time standards for > 25+ years until they were replaced by the 5071A in the 1990s. > > ___ > 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
On 2/24/2019 4:02 AM, Rice, Hugh (IPH Writing Systems) wrote: Several people have asked about the Len Cutler ban on Aluminum Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist could shed more light on this too. The legend of the ban was passed along to me, perhaps by Lou Mueller, who liked to tell stories of the old days. In 1985, we were not taking the ban literally. For example, the 2400uF main power supply filter capacitor was AL-Electrolytic, as were a few other smaller capacitors on the power regulator. I sidestepped the capacitor issues on my simple battery charger by not having a filter cap after This discussion is the first I had heard of a ban on aluminum electrolytics in the Cs standards. All I know is that in the early stages of the 5071 project, Len proposed using a tantalum capacitor for the power supply filter. None of the members of the project time were aware of the history of this, and we objected. I vaguely remember the cap would have cost something like $50. Len eventually backed down on that idea and in any event, the question became moot when we went with the Vicor power modules, which surely had aluminum caps at the front end for energy storage. The Vicor's seemed very avante garde at the time, but in practice they worked very well and were very reliable. A related thing happened in other instruments. Previously, power supplies in instruments were built from scratch, and there were various reliability dictates, like derating capacitors, etc. Then it started to make sense to purchase off line switchers. These violated all sorts of "rules", yet they got a pass and became SOP. The R lab manager at Santa Clara Division famously said "no customer chooses HP products because they have great power supplies." Rick ___ 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] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
Several people have asked about the Len Cutler ban on Aluminum Electrolytic Capacitors in HP Frequency Standards. Rick Karlquist could shed more light on this too. The legend of the ban was passed along to me, perhaps by Lou Mueller, who liked to tell stories of the old days. In 1985, we were not taking the ban literally. For example, the 2400uF main power supply filter capacitor was AL-Electrolytic, as were a few other smaller capacitors on the power regulator. I sidestepped the capacitor issues on my simple battery charger by not having a filter cap after the transformer/full-wave-bridge, and just used 120 Hz pulses, since the battery didn't care about DC vs. pulsed DC. (I thought it was pretty clever to leave out the main filter cap.) Where possible, Tantalum capacitors were used.For the few places where AL caps were used, they were heavily de-rated, operating at 50% of rated voltage for example. As one reader pointed out, back in the 1965 when the 5060A was developed, AL-Electrolytic caps were likely a lot less reliable than in 1985 when I worked on the 5061B. From: time-nuts On Behalf Of Rice, Hugh (IPH Writing Systems) Sent: Saturday, February 23, 2019 8:49 PM To: time-nuts@lists.febo.com Subject: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments. Hello Time-Nuts, Stuff deleted . It was fantastically reliable. Only linear power circuits, with robust heat sinking of all power devices. The legendary Len Cutler ban on aluminum electrolytic capacitors. 5060s were still in use in 1985, after 20 years of constant operation. Likewise, 5061As were abundant in time standards for 25+ years until they were replaced by the 5071A in the 1990s. ___ 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.
