[time-nuts] HP 5328A
Dick Moore
richiem at hughes.net
Thu Sep 10 04:00:28 UTC 2009
Hi, Brent and Doug -- my copy of the 5328 schematic shows a 0.47 ohm
resistor in series with F1, a 2A fast-blo fuse. I would be sure that
the current is flowing thru the fuse -- is it F1 on the P.S. board
that's blowing?. As Brent said, using a Variac and then putting an AC
ammeter across the empty fuse holder would certainly help confirm
that. This is the unregulated +25 supply and it feeds lots of things.
There's a 47uF cap hanging off the downstream side of the fuse -- I'd
look at that, and at Q1, CR3 and CR7 first. If L1's frame is grounded,
I would check L1 for a shorted winding to frame. A solder bridge
somewhere is always a possibility if you're not the first person to
work on this unit. I no longer own one of these, but I can kibbitz
with you if it'll help. If it's more convenient, email me at: richiem at hughes.net
Best,
Dick Moore
On Sep 9, 2009, at 6:47 PM, time-nuts-request at febo.com wrote:
>
> Message: 2
> Date: Wed, 09 Sep 2009 14:53:15 -0600
> From: Brent Gordon <time-nuts at adobe-labs.com>
> Subject: Re: [time-nuts] HP 5328 PSU nightmare... Or stupid engineer,
> you decide...
> To: contact at pupcostudios.com, Discussion of precise time and
> frequency measurement <time-nuts at febo.com>
> Message-ID: <4AA815BB.2020300 at adobe-labs.com>
> Content-Type: text/plain; charset=EUC-KR
>
> I'm not familiar with this particular instrument, but a standard
> technique for linear power supplies is to hook it up to a variac. This
> lets you turn down the line voltage so you can do some measurements
> without smoking the system.
>
> Brent
>
> Douglas Wire - PUPCo Studios wrote:
>> Good day everyone and thank you all for hosting this wonderful
>> community
>> and allowing me to participate. I have several HP5328 with the ?
>> really-
>> nice? newer 10811-xxxxx Oscillators in them. I have found while I
>> have
>> used the good old gold trace reliable HP instruments all of my
>> life, these
>> units have been especially difficult. The first unit the 4500uF
>> electrolytic?s went bad and produced essentially a dead short; an
>> easy
>> enough repair for me to not only track down in minutes, but it only
>> takes a
>> straight bit screwdriver to fix in seconds!
>>
>>
>>
>> Now our second unit has been giving me fits and while I would agree
>> 100%
>> with one of the posts I saw here about how well HP did not only
>> with their
>> schematics, but also the wonderful troubleshooting flow charts
>> usually make
>> repairs on any of their old units a breeze. Sadly I have a unit
>> here that
>> is giving us fits! It is a PSU issue and not related to the
>> Motherboard or
>> any of the cards as I tested it with everything unhooked/
>> unsoldered and
>> still got the same result. It is quite similar to what we see when
>> we get
>> an old HP unit that has a fried cap and is darn near creating a
>> short to
>> ground, but alas I simply cannot find the problem (I am sure it is
>> starring
>> me in the face is and I just can?t see it?) What I am seeing is super
>> high current flow through the R1 (I believe, but HP?s every unit I
>> have
>> ever serviced had.47? resistor, NOT a 22-? as is stated in the
>> schematic?) that leads to F1. The troubleshooting is complicated by
>> the
>> fact that unless I want to smoke that heavy duty, relatively close
>> tolerance resistor, I cannot even check voltages anywhere for it
>> will blow
>> the fuse or if I put a slow blow to try and catch some measurements
>> in a
>> second or two, well that is not very feasible either.
>>
>>
>>
>> If I had to guess, I would say it has either a cap that has fried,
>> outside
>> chance of a transformer issue, or the way this thing reacts, pretty
>> well an
>> effective dead short somewhere, but I will be damned if I can find
>> the
>> problem anywhere. I replaced the bad and 4500uF caps as well as the
>> rectifier, wondering if part of it had blown with no change in its
>> issues.
>> One cannot follow the flow cart to much of anything other than
>> boxes that
>> say look for a short, but so many areas one tests even on a perfectly
>> working unit come clear down near the zero ? point even when they are
>> operating correctly.
>>
>>
>>
>> I apologize if 1) this is not a clear email that anyone can easily
>> understand and 2) I almost feel embarrassed to ask anyone for
>> advice from
>> their practical experience, for I feel as If I should easily be
>> able to get
>> to the bottom of this in a matter of minutes with the wonderful
>> data HP
>> provides us all for these old workhorses.
>>
>>
>>
>> So if anyone has run into a problem such as this in the past where
>> working
>> the flow chart only yields No, No, No -> check for shorts and has any
>> advice for how I might logically proceed, or what in fact you have
>> found
>> out in dealing with a similar problem, it would be of great help,
>> as we
>> need this in-service ASAP, but I guess I just cannot see the forest
>> for the
>> tress in front of me or something here? Any advise, suggestions
>> would be
>> greatly appreciated.
>>
>>
>>
>> I would like to become a more active participant here with all I can
>> contribute, which hopefully soon should be a lot as I am doing some
>> innovative timing and generation processes that I am relatively
>> sure the
>> outcome and data from derived from it could be of great benefit to
>> the TIME-
>> NUTS userbase here. Thanks and don?t be too hard on me for asking
>> (what to
>> me sounds like a stupid amateur question) but I am either too tired
>> to
>> reason correctly, or it is just one of those very pesky problems,
>> that
>> hopefully someone has identified before and might be able to
>> enlighten us
>> over. I am begiinign to wonder if a voltage regulator might be
>> responsible,
>> but I am at a loss at the moment and have not had enough sleep to
>> properly
>> think this repair through? Thank you again everyone!
>>
>>
>>
>> Warm regards,
>>
>> Douglas M. Wire, GED, FNA,
>>
>> PUPCo Studios, PUPCo Research Group
>>
>>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 9 Sep 2009 14:00:50 -0700
> From: Corby Dawson <cdelect at juno.com>
> Subject: [time-nuts] 5071A tube EEPROM and tube data
> To: time-nuts at febo.com
> Message-ID: <20090909.140050.3720.6.cdelect at juno.com>
> Content-Type: text/plain; charset=us-ascii
>
> "The HP tubes used a heated metal "burst" diaphragm not glass ampoules
> to"
>
> Dave,
>
> Actually, YES.
>
> I dug up the oven I had opened up and it is as I remembered.
>
> The cesium ampoule is all metal and sits upside down in the center
> of the
> "wicking" screen.
>
> The center of the burst diaphragm is welded to a post that comes out
> the
> top of the oven via an insulated feedthru.
>
> When they want to free the cesium they apply a high current thru the
> post
> and it melts a hole where the post was welded to the diaphragm.
>
> NO glass inside the wicking or inside the ampoule.
>
> I'm not saying other tubes dont have glass but HP tubes DO NOT.
>
> I'll see if I can look thru my box of ovens and if I have an FTS oven
> I'll cut it open and see.
>
> Corby Dawson
>
> I do have PIX of the above but nowhere to post them!
> ____________________________________________________________
> Best Weight Loss Program - Click Here!
> http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTFoYc8NnQJkcgLgSo51uNiMATy3jTTMkZTC0ONLV4HTEeAMAime4I/
>
>
>
> ------------------------------
>
> Message: 4
> Date: Thu, 10 Sep 2009 09:10:24 +1200
> From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
> Subject: Re: [time-nuts] HP 5328 PSU nightmare... Or stupid engineer,
> you decide...
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <4AA819C0.20403 at xtra.co.nz>
> Content-Type: text/plain; charset=EUC-KR
>
> Neither the linear regulators nor the switching regulators in the
> 5328A have
> any explicit current limiting circuitry other than that provided by
> the
> pass transistor current gain and the limited current available from
> the
> pass element driver.
>
> The only protection against long term load faults is provided by the
> fuses
> at the regulator inputs. However these fuses don't protect against
> shorted rectifier output filter capacitors etc.
>
> Bruce
>
> Brent Gordon wrote:
>> I'm not familiar with this particular instrument, but a standard
>> technique for linear power supplies is to hook it up to a variac.
>> This
>> lets you turn down the line voltage so you can do some measurements
>> without smoking the system.
>>
>> Brent
>>
>> Douglas Wire - PUPCo Studios wrote:
>>
>>> Good day everyone and thank you all for hosting this wonderful
>>> community
>>> and allowing me to participate. I have several HP5328 with the ?
>>> really-
>>> nice? newer 10811-xxxxx Oscillators in them. I have found while I
>>> have
>>> used the good old gold trace reliable HP instruments all of my
>>> life, these
>>> units have been especially difficult. The first unit the 4500uF
>>> electrolytic?s went bad and produced essentially a dead short; an
>>> easy
>>> enough repair for me to not only track down in minutes, but it
>>> only takes a
>>> straight bit screwdriver to fix in seconds!
>>>
>>>
>>>
>>> Now our second unit has been giving me fits and while I would
>>> agree 100%
>>> with one of the posts I saw here about how well HP did not only
>>> with their
>>> schematics, but also the wonderful troubleshooting flow charts
>>> usually make
>>> repairs on any of their old units a breeze. Sadly I have a unit
>>> here that
>>> is giving us fits! It is a PSU issue and not related to the
>>> Motherboard or
>>> any of the cards as I tested it with everything unhooked/
>>> unsoldered and
>>> still got the same result. It is quite similar to what we see when
>>> we get
>>> an old HP unit that has a fried cap and is darn near creating a
>>> short to
>>> ground, but alas I simply cannot find the problem (I am sure it is
>>> starring
>>> me in the face is and I just can?t see it?) What I am seeing is
>>> super
>>> high current flow through the R1 (I believe, but HP?s every unit I
>>> have
>>> ever serviced had.47? resistor, NOT a 22-? as is stated in the
>>> schematic?) that leads to F1. The troubleshooting is complicated
>>> by the
>>> fact that unless I want to smoke that heavy duty, relatively close
>>> tolerance resistor, I cannot even check voltages anywhere for it
>>> will blow
>>> the fuse or if I put a slow blow to try and catch some
>>> measurements in a
>>> second or two, well that is not very feasible either.
>>>
>>>
>>>
>>> If I had to guess, I would say it has either a cap that has fried,
>>> outside
>>> chance of a transformer issue, or the way this thing reacts,
>>> pretty well an
>>> effective dead short somewhere, but I will be damned if I can find
>>> the
>>> problem anywhere. I replaced the bad and 4500uF caps as well as the
>>> rectifier, wondering if part of it had blown with no change in its
>>> issues.
>>> One cannot follow the flow cart to much of anything other than
>>> boxes that
>>> say look for a short, but so many areas one tests even on a
>>> perfectly
>>> working unit come clear down near the zero ? point even when they
>>> are
>>> operating correctly.
>>>
>>>
>>>
>>> I apologize if 1) this is not a clear email that anyone can easily
>>> understand and 2) I almost feel embarrassed to ask anyone for
>>> advice from
>>> their practical experience, for I feel as If I should easily be
>>> able to get
>>> to the bottom of this in a matter of minutes with the wonderful
>>> data HP
>>> provides us all for these old workhorses.
>>>
>>>
>>>
>>> So if anyone has run into a problem such as this in the past where
>>> working
>>> the flow chart only yields No, No, No -> check for shorts and has
>>> any
>>> advice for how I might logically proceed, or what in fact you have
>>> found
>>> out in dealing with a similar problem, it would be of great help,
>>> as we
>>> need this in-service ASAP, but I guess I just cannot see the
>>> forest for the
>>> tress in front of me or something here? Any advise, suggestions
>>> would be
>>> greatly appreciated.
>>>
>>>
>>>
>>> I would like to become a more active participant here with all I can
>>> contribute, which hopefully soon should be a lot as I am doing some
>>> innovative timing and generation processes that I am relatively
>>> sure the
>>> outcome and data from derived from it could be of great benefit to
>>> the TIME-
>>> NUTS userbase here. Thanks and don?t be too hard on me for asking
>>> (what to
>>> me sounds like a stupid amateur question) but I am either too
>>> tired to
>>> reason correctly, or it is just one of those very pesky problems,
>>> that
>>> hopefully someone has identified before and might be able to
>>> enlighten us
>>> over. I am begiinign to wonder if a voltage regulator might be
>>> responsible,
>>> but I am at a loss at the moment and have not had enough sleep to
>>> properly
>>> think this repair through? Thank you again everyone!
>>>
>>>
>>>
>>> Warm regards,
>>>
>>> Douglas M. Wire, GED, FNA,
>>>
>>> PUPCo Studios, PUPCo Research Group
>>>
>>>
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 09 Sep 2009 22:24:43 +0100
> From: Dave Ackrill <dave.g0dja at tiscali.co.uk>
> Subject: Re: [time-nuts] High accuracy? GPS position
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Message-ID: <4AA81D1B.5040105 at tiscali.co.uk>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Murray Greenman wrote:
>> Mark,
>> How do you KNOW your position to such accuracy? Is it in fact
>> possible
>> to survey your position to that accuracy by any independent means?
>>
>> If, for example, you use official survey marks to determine your
>> position by direct measurement, are the survey marks really that
>> accurate?
>
> Yes, I have a National Survey Bolt mark just down the road from me.
>
> Dave (G0DJA)
>
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 9 Sep 2009 17:54:12 EDT
> From: GandalfG8 at aol.com
> Subject: Re: [time-nuts] High accuracy? GPS position
> To: time-nuts at febo.com
> Message-ID: <c38.5f18a099.37d97e04 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
>
> In a message dated 09/09/2009 22:25:22 GMT Daylight Time,
> dave.g0dja at tiscali.co.uk writes:
>
> How do you KNOW your position to such accuracy? Is it in fact
> possible
>> to survey your position to that accuracy by any independent means?
>>
>> If, for example, you use official survey marks to determine your
>> position by direct measurement, are the survey marks really that
>> accurate?
>
> Yes, I have a National Survey Bolt mark just down the road from me.
>
>
>
> --------------------
>
> I'm not sure that completely answers the question.
>
>
> Even if we assume that the position of the bolt mark is known to an
> accuracy of an inch or so, have you measured your antenna position
> in relation to
> that with sufficient precision in distance and bearing so as to
> transfer
> that accuracy to the antenna location?
>
> regards
>
> Nigel
> GM8PZR
>
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 9 Sep 2009 23:43:46 +0000
> From: Mark Sims <holrum at hotmail.com>
> Subject: Re: [time-nuts] time-nuts Digest, Vol 62, Issue 25
> To: <time-nuts at febo.com>
> Message-ID: <BLU125-W2386651EF172595A19D60CCEE90 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> I have a geodetic grade Ashtech Z12 GPS receiver and antenna. You
> collect data with it (both L1 and L2 carrier phase) and email the
> data to the National Geodetic Survey OPUS processing system. They
> crunch the numbers and come back with a location (it's free).
>
> The location is calculated by crunching the numbers against the data
> collected simultaneously at 3-9 CORS reference stations. The CORS
> network is a network of several hundred fixed high-precision GPS
> stations that continuously collect data and monitor and cross-check
> each other.
>
> Included in the OPUS results is an error estimate. I have done
> several runs and the error estimates are usually under 4mm. However
> if you compare the spread in the actual locations generated, they
> are usually within 400 microns.
>
> I am pretty darn sure I know where I am... except that I am
> drifting across the planet at about 10 mm / year. (The location
> info for the CORS reference stations includes a velocity vector).
> And let's not get into things like thermal expansion of my front
> deck and tidal deformation of the earth's crust...
>
> ----------------------------------------
>
> How do you KNOW your position to such accuracy? Is it in fact
> possible to survey your position to that accuracy by any independent
> means?
> _________________________________________________________________
> Windows Live: Keep your friends up to date with what you do online.
> http://windowslive.com/Campaign/SocialNetworking?ocid=PID23285::T:WLMTAGL:ON:WL:en-US:SI_SB_online:082009
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 9 Sep 2009 20:48:08 -0500
> From: "Jeff Schmidt" <jas at jschmidt.org>
> Subject: [time-nuts] FreeBSD: ntpd PPS vs. kernel PPS
> To: <time-nuts at febo.com>
> Message-ID: <001201ca31b8$bfc2f950$3f48ebf0$@org>
> Content-Type: text/plain; charset="us-ascii"
>
> So, I have been running a FreeBSD GPS disciplined NTP server for
> some time.
> While there is a lot of guidance out there about how to do-it-
> yourself with
> a Garmin LVC 18 and FreeBSD, I was unable to find any quantitative
> data
> about whether the PPS was best handled in the FreeBSD kernel or in
> the ntpd
> driver. So, here is some data:
>
> FreeBSD tick.jschmidt.org 7.2-RELEASE
>
> Kernel PPS discipline was enabled as follows:
>
> Kernel built with "options PPS_SYNC" (GENERIC + PPS_SYNC)
>
> Relevant portions of ntp.conf:
>
> # GPS NMEA (numbers seconds only)
> server 127.127.20.0 prefer minpoll 4 maxpoll 4
> #flag3 Controls the kernel PPS discipline: 0 for disable
> (default), 1 for
> enable.
> fudge 127.127.20.0 flag3 1
>
> # GPS PPS
> server 127.127.22.0 minpoll 4 maxpoll 4
> #flag3 Controls the kernel PPS discipline: 0 for disable
> (default), 1 for
> enable.
> fudge 127.127.22.0 flag3 1
> fudge 127.127.22.0 refid GPS
>
> Similarly, ntpd PPS discipline was enabled as follows:
>
> No "options PPS_SYNC" (just a GENERIC kernel)
>
> ntp.conf:
>
> fudge 127.127.20.0 flag3 0
> fudge 127.127.22.0 flag3 0
>
> No other changes - software, environmental, etc. See the graphs here:
>
> http://www.jschmidt.org/loops.jpg
>
> http://www.jschmidt.org/loops2.jpg
>
> The box was running the ntpd PPS discipline from approximately 14260
> thru
> 14445. It was running kernel PPS discipline prior to 14260 and
> after 14445.
> Visually, you can clearly see that the kernel PPS discipline is
> superior to
> the ntpd PPS discipline.
>
> # ntpdc -c version
> ntpdc 4.2.4p7 at 1.1607-o Sat Jul 18 14:35:11 UTC 2009 (1)
>
> # ntptime
> ntp_gettime() returns code 0 (OK)
> time ce52bc08.62922d70 Wed, Sep 9 2009 19:43:04.385, (.385043152),
> maximum error 995 us, estimated error 1 us, TAI offset 34
> ntp_adjtime() returns code 0 (OK)
> modes 0x0 (),
> offset 5.788 us, frequency -11.256 ppm, interval 256 s,
> maximum error 995 us, estimated error 1 us,
> status 0x2107 (PLL,PPSFREQ,PPSTIME,PPSSIGNAL,NANO),
> time constant 4, precision 0.001 us, tolerance 496 ppm,
> pps frequency -11.256 ppm, stability 0.027 ppm, jitter 0.933 us,
> intervals 17651, jitter exceeded 13839, stability exceeded 0,
> errors 5.
>
> Hope this is interesting/helpful, thx,
> Jeff Schmidt
>
>
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please visit http://www.messagelabs.com/email
> ______________________________________________________________________
>
>
>
> ------------------------------
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
> End of time-nuts Digest, Vol 62, Issue 27
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