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HP 3468 voltmeter with HP-IL
06-16-2015, 04:09 PM
Post: #21
RE: HP 3468 voltmeter with HP-IL
Hi Artur,

many thanks for your comment. I take it into account. I will se how it goes...if it is feasible I shall go ahead, if not, I shall desist...Anyway: thanks for your contribution.
Kind regards from Spain[/i]


Ignacio
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06-17-2015, 04:01 AM
Post: #22
RE: HP 3468 voltmeter with HP-IL
(06-16-2015 02:05 PM)Mark Hardman Wrote:  
(06-16-2015 05:11 AM)4ster Wrote:  I missed the last one he sold that had the battery option. I was about to pull the trigger but someone beat me to it. I hesitated over the higher price he charged for the unit. As I look into these units I'm thinking his services are worth the higher price.

As a forester, you might be interested in the follow story about Larry's work (follow the link to the .pdf):

The QIC and the Dead

"Dr. Norman Pillsbury was an early 9825 user who was recently pulled back into the HP 9825’s orbit by a lawsuit. As a California registered forester, Dr. Pillsbury testified in a woodcutting case. Back in the 1980s, Dr. Forrester got a grant to analyze harvesting volumes from tree cuttings. He developed sophisticated programs on the HP 9825 to estimate the volume of usable wood obtained from tree harvesting. Decades later, his efforts as an expert witness prompted him to rediscover his DC100 tapes, to purchase an old HP 9825, and to try to recover the programs and data from those tapes [With major assistance from Larry Atherton]. His story is fascinating."

Click here to download his story.

Thanks for that, I really enjoyed the read. I just finished (if a program is ever really finished) writing a program on my 41 to calculate conifer tree volume for timber cruising. It duplicates an old method used by my boss years ago when I first started working as a forester. It was more for nostalgia than for actual timber cruising. Calculating volumes of conifer trees is much easier to do than calculating the volume of the oak in the link!
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08-16-2015, 10:47 PM
Post: #23
RE: HP 3468 voltmeter with HP-IL
3468A with battery sold for $63 today. Did you get it?
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08-17-2015, 09:47 AM (This post was last modified: 08-18-2015 08:56 AM by Martin Hepperle.)
Post: #24
RE: HP 3468 voltmeter with HP-IL
(06-16-2015 08:39 AM)Sadsilence Wrote:  ...
Regarding battery option: I asked him how easy it is to access battery (with intention to recharge it with an external loader, when there would have been no possibility to jumper HP 3468 for 240 VAC). His reply: Difficult, even for experienced.

Just an additional comment on the batter/batteries:

I just got a 3468A with the battery option and opened it to check the state of the dead battery - it is easy to access and replace the (rechargable) battery.
I was happy to have checked the battery, as it was already leaking and some acid was accumulating between battery and battery holder (luckily not yet dripping down on the PCB). So I would strongly advise to at least to check the state of the battery if you have such a battery powered DVM older than, say, 10 years. Even a "sealed" battery may leak.
Suitable batteries of 6V/3.6Ah or 6V/3.8Ah are avilable from 3rd parties, also a smaller 6V/2.4Ah (as used e.g. in the HP 9144 floppy disk drives) fits, in case you do not have a 3.X Ah battery of the required dimensions at hand.
The smaller battery may suffer from a too high charging current, though, so it should be replaced with the proper capacity in the long run.

As already mentioned, the other battery to check is the 3V Lithium primary cell which feeds the calibration memory. This one is below a aluminum cover which is a little bit difficult to remove due to limited access space and tight cables. Such a battery may easily last 10 years or more.

Martin
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08-17-2015, 03:06 PM (This post was last modified: 08-17-2015 03:22 PM by 4ster.)
Post: #25
RE: HP 3468 voltmeter with HP-IL
(08-16-2015 10:47 PM)Dave Frederickson Wrote:  3468A with battery sold for $63 today. Did you get it?

I picked one up a few weeks ago from "la-tech-renewal" mentioned in this thread. I spent a lot more money, but both the calibration battery and the working battery are new and the meter was calibrated before it was shipped. The case is in great condition and it almost looks new. I'm very happy with it. Some of the cheap 3468s on Ebay look like a lot higher milage meters than mine. That one looks like it was a great buy.

One hick-up I had was getting the meter to be recognized on the loop. It's my understanding that the A model has the carry handle and may have the battery option, while the B model is the bench version. My case says HP3468A all over it, but it would not be recognized on the loop using the INI68 program in the meter's manual. For some reason I tried "HP3468B" for the FINDID command and it worked. So I am guessing that somewhere along the way this meter has had some major surgery. Works great though.

First project with the meter is to automate a test I do to check the health of oxygen cells. The test procedure is to measure mV output of 4 cells under various partial pressures of O2 from .21 (air) to 2.0 (O2 at 2 atm) making sure the response is linear. It involves 30 measurements that I have been recording by hand and entering in a spreadsheet. Its a fun little project to get the 41 to store the data and produce a report.
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08-17-2015, 03:58 PM
Post: #26
RE: HP 3468 voltmeter with HP-IL
(08-17-2015 03:06 PM)4ster Wrote:  
(08-16-2015 10:47 PM)Dave Frederickson Wrote:  3468A with battery sold for $63 today. Did you get it?

I picked one up a few weeks ago from "la-tech-renewal" mentioned in this thread. I spent a lot more money, but both the calibration battery and the working battery are new and the meter was calibrated before it was shipped. The case is in great condition and it almost looks new. I'm very happy with it. Some of the cheap 3468s on Ebay look like a lot higher milage meters than mine. That one looks like it was a great buy.

One hick-up I had was getting the meter to be recognized on the loop. It's my understanding that the A model has the carry handle and may have the battery option, while the B model is the bench version. My case says HP3468A all over it, but it would not be recognized on the loop using the INI68 program in the meter's manual. For some reason I tried "HP3468B" for the FINDID command and it worked. So I am guessing that somewhere along the way this meter has had some major surgery. Works great though.

First project with the meter is to automate a test I do to check the health of oxygen cells. The test procedure is to measure mV output of 4 cells under various partial pressures of O2 from .21 (air) to 2.0 (O2 at 2 atm) making sure the response is linear. It involves 30 measurements that I have been recording by hand and entering in a spreadsheet. Its a fun little project to get the 41 to store the data and produce a report.

Very good. I just had Larry refurb the tape drive on my 85B.

I have a 3468B so there's probably no point in checking the ID on mine. Picked up two manuals for the 3468 from Manuals Plus last week for cheap before they closed.

Dave
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08-18-2015, 02:34 PM
Post: #27
RE: HP 3468 voltmeter with HP-IL
(08-17-2015 03:58 PM)Dave Frederickson Wrote:  Very good. I just had Larry refurb the tape drive on my 85B.

I have a 3468B so there's probably no point in checking the ID on mine. Picked up two manuals for the 3468 from Manuals Plus last week for cheap before they closed.

Dave

How is the bar code in the manuals? All copies of manuals that I have been able to locate have unreadable bar code. I would buy a manual with good barcode, but the CD that came with the unit is OK for everything but the barcode.
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08-18-2015, 04:03 PM
Post: #28
RE: HP 3468 voltmeter with HP-IL
(08-18-2015 02:34 PM)4ster Wrote:  How is the bar code in the manuals? All copies of manuals that I have been able to locate have unreadable bar code. I would buy a manual with good barcode, but the CD that came with the unit is OK for everything but the barcode.

Tucker has manuals for $25. They also sell on eBay as teoutlet, so you might be able to negotiate a better price if you buy the service manual, too.

Dave
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08-19-2015, 04:06 AM
Post: #29
RE: HP 3468 voltmeter with HP-IL
(08-18-2015 04:03 PM)Dave Frederickson Wrote:  
(08-18-2015 02:34 PM)4ster Wrote:  How is the bar code in the manuals? All copies of manuals that I have been able to locate have unreadable bar code. I would buy a manual with good barcode, but the CD that came with the unit is OK for everything but the barcode.

Tucker has manuals for $25. They also sell on eBay as teoutlet, so you might be able to negotiate a better price if you buy the service manual, too.

Dave

Thanks for the lead.
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08-19-2015, 01:03 PM (This post was last modified: 08-19-2015 01:04 PM by Ángel Martin.)
Post: #30
RE: HP 3468 voltmeter with HP-IL
As it happens I have one of those that haven't been used in years (I'm not doing much design anymore) - so it'll be put for sale soon. It's not calibrated and also can't locate the test probes. The manual is included (a copy at least). Drop me a PM if anyone's interested.
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