[volt-nuts] 3458A A5 board

[Randy Scott]

Dick,

How were you able to order the replacement A5 (outguard controller) board?  From Agilent's website, it does not appear that I can order the original through-hole (03458-66505), the SMT (03458-66547) or the upgrade kit (03458-80047).

My cal NVRAMs are past their expiration date (but still working) and I've been reluctant to replace them.  My main concern is that I won't be able to remove the NVRAMs intact enough to read their contents and program into replacements (which I would put into sockets).  My go-to technique for replacing DIP packages usually involves a wire cutter. :)

Randy.


--- On Thu, 8/26/10, Roy Phillips <phill.r1 at btinternet.com> wrote:

> From: Roy Phillips <phill.r1 at btinternet.com>
> Subject: Re: [volt-nuts] volt-nuts Digest, Vol 12, Issue 11
> To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
> Date: Thursday, August 26, 2010, 9:32 AM
> Dick
> I have read the exchanges on the subject of the HP3458A
> with considerable interest.  I purchased a working
> 3458A about a year ago from a source which in turn had
> obtained it from a large Companies Lab. when it closed
> down.  It was in pretty good condition overall, but it
> has the ROM board with the Dallas ROMs'  fitted, and I
> await the day in trepidation when they "run out", but I
> would prefer to replace the board as you have, with the
> later type.  As for calibration, mine was last cal'd by
> Agilent (here in the UK) on 27/02/2007 with a next cal due
> date of 27/02 /2009. To date the instrument has performed
> faultlessly. I anticipate that to replace the ROM board with
> one obtained from Agilent UK would be very expensive,
> judging from prices for other HP equipment
> replacement/repair prices. As you may know, we in the UK
> usually pay the same amount in UK pounds that you in the US
> pay in dollars. Has anyone in the UK purchased this item ?
> Best regards.
> Roy
> 
> 
> --------------------------------------------------
> From: "Dick Moore" <richiem at hughes.net>
> Sent: Wednesday, August 25, 2010 8:26 PM
> To: <volt-nuts at febo.com>
> Subject: Re: [volt-nuts] volt-nuts Digest, Vol 12, Issue
> 11
> 
> > Hi, Marv -- RE my 3458 -- It was very clean
> externally, leading me to think it had been used in a test
> or lab environment, but it needed a display board and a ROM
> board, both of which I installed. Then it went to Loveland
> for calibration. That was last September. Because the ROM
> board was replaced, there was no "before" data to compare
> the cal to. It goes back to Loveland this September, and now
> there will be "before" and "after" data which will provide
> an estimate of drift in parameters. It is not an -02
> high-stability option unit.
> > 
> > The ROM board change essentially made this a
> good-as-new unit, at least according to Loveland -- it
> passed all pre-cal tests with flying colors and cal'ed
> without problems.
> > 
> > I believe that Loveland uses a Fluke 572x calibration
> system, which for DC is at least as good as the 732B. As to
> AC -- well I think it probably is as good as there is right
> now for cal use outside of labs. The specs for the 3458
> reflect the uncertainty of the calibration standards, and
> the AC specs definitely show that. I bought that 3458 for
> $1600 on fleabay --  didn't want to pay too much more
> because of the ROM battery problems on older units with the
> Dallas ROMs that had built-in battery back up. The new ROM
> board has ROMs that have a snap-on battery which is
> apparently easy to replace, though I wonder how long they
> will be available via Agilent....
> > 
> > In any case, the display board was $400+, the ROM
> board was $500+ and the cal was about $500, so my total
> investment to this point is around $3100 -- a lot, but worth
> it. I just trust the 3458 without wondering if it is right.
> It is the only high-res measurer in the shop now, so it is
> right by definition. As Steve Rooke likes to say, "A man
> with one clock knows what time it is. A man with two clocks
> isn't ever sure."
> > 
> > Best,
> > Dick Moore
> > 
> > 
> > On Aug 25, 2010, at 5:00 AM, volt-nuts-request at febo.com
> wrote:
> > 
> >> Message: 1
> >> Date: Tue, 24 Aug 2010 19:52:37 -0400
> >> From: "Marvin E. Gozum" <marvin.gozum at jefferson.edu>
> >> Subject: Re: [volt-nuts] Back to voltage
> >> To: Discussion of precise voltage measurement
> <volt-nuts at febo.com>,
> >> volt-nuts at febo.com
> >> Message-ID: <6.2.5.6.2.20100824183805.0504e360 at jefferson.edu>
> >> Content-Type: text/plain; charset="us-ascii";
> format=flowed
> >> 
> >> Hello Dick,
> >> 
> >> Thanks for your input.  Your posts on
> time-nuts have been invaluable
> >> as was the thread here and all its contributors:

> >> 
> >> http://www.mail-archive.com/time-nuts@febo.com/msg16497.html
> >> 
> >> The last I read on time and volt nuts, your HP
> 3458a had it share of
> >> trouble, but you describe here its working true
> now, did it take much
> >> to get back into factory shape?
> >> 
> > 
> > 
> > _______________________________________________
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> > 
> 
> 
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