HP 3968A - Page 1
Forum section: electronics / testgear

author: Jwalling
author_rank: Unknown
timestamp: August 12, 2017, 10:16:46 am
content: Never seen one of these before, so I tried to find a manual out of curiosity. Nothing except for a mention in a bench brief from 1976.http://www.ebay.com/itm/HP-3968A-Industrial-Data-Acquisition-Instrumentation-Reel-To-Reel-Tape-Recorder-/152660479131?hash=item238b460c9b:g:hmoAAOSwjIRZjof~www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1976-09-12.pdfAnyone have a pdf manual for this?

author: alm
author_rank: Super Contributor
timestamp: August 12, 2017, 10:41:48 am
content: Attached is a two-page excerpt from the 1980 HP catalog with technical specifications. These things were expensive (over $7k in 1980). I do not have a copy of the manual.

author: Jwalling
author_rank: Unknown
timestamp: August 12, 2017, 12:58:02 pm
content: Quote from: alm on August 12, 2017, 10:41:48 amInteresting, thanks. I guess I don't really understand what practical uses this device would have...

author: alm
author_rank: Super Contributor
timestamp: August 12, 2017, 01:16:55 pm
content: Recording analog data for further analysis I imagine. For example, you might analyze the result on a scope or LF spectrum analyzer, or plot it on a piece of paper at a slower speed. Obviously bandwidth is limited to slightly beyond audio frequencies, but much better than a paper recorder or human writing frantically with a pencil.This was before digital storage that was fast enough to keep up was common. The only fast alternative would be an analog storage scope, but that is limited to one screen full of data, and long-time storage is limited to Polaroids.

author: wn1fju
author_rank: Frequent Contributor
timestamp: August 12, 2017, 01:28:27 pm
content: I have the HP 3964A, which is the 4-channel variant. These are what they advertise - instrumentation recorders. Used to acquire sensor datasuch as voice, vibration, voltage, temperature, strain gauge, or whatever else you can think of. Although the basic tape transport mechanismis the same, these recorders were offered with different channel acquisition electronics. There is the FM variant that goes down to DC, and thedirect record variant that doesn't (but it does go to 64 kHz on the high end). My unit is packed with the FM cards.As is typical with 1970 HP stuff, it is built like a tank. I only paid a few bucks for mine (I mean, who would really want one of these things?),and it needed to have the pinch roller re-rubberized since it had turned into goop.My biggest problem was finding adequate tape. It was optimized for 3M888 tape, good luck! I pieced together some old tape and atleast verified that everything worked correctly. Old tape has a tendency to flake off and crud up the record head very quickly. There aresome suggested tape restoration procedures that involve baking the tape for a while, but I didn't try that.While I was in my "tape recorder" phase, I also managed to score a Racal 14DS 14-channel recorder. Now there's a real beast. And a whilelater, that one developed problems with the oil-dampened tension arms, so I scored another one. 99 cents on eBay for that one (plusshipping)!!!