[FS UK] Vintage Grass Polygraph Machine & Chart Recorder - Price Reduced! - Page 1
Forum section: electronics / general

author: dexters_lab
author_rank: Unknown
timestamp: June 17, 2016, 08:28:39 am
content: So recently i was offered the chance to take ownership of something special but i need to make room for it, so i will need to sell my polygraph machine that was featured on the forum and on my youtube channel last year.It's a 1970s vintage Grass Instruments 78D Polygraph and it's chart recorder.It consists of the main rack, chart recorder and:3X Low Level DC Pre-Amps1X EKG & Tachogrpah Pre-Amp1X Polygraph Integrator1X Wide-Band AC Pre-Amp6X DC Driver Amplifiers5X EEG Data Processing Amplifiers11X Pen Actuators1X Patch board with Grass connectors2X Boxes Grass Instruments chart paperI don't believe it's in original configuration, there does seem to be modules dating from the early 1980s in it too, these were modular so not surprising things have been changed around in the last 4+ decades.The amps and pre-amps all seem to be working as far as i can tellThe pen actuators are working but the arms are not in good shape, they are all bent in some wayThe inkwells and capillary tubes have dried up and are probably clogged.The main system power supply has been repaired with new-old-stock parts and is workingThe paper drive mechanism for the chart recorder is working, though the rubber drive wheel probably needs replacing as it's perished.There is a picture attached but it's an old pic, i will take some additional pictures and a walk-around video next week and add them to this post.It's a very interesting and eye catching piece constructed mostly in stainless steel and brushed aluminium, the main rack is bolted to the chart recorder which has wheels so i can be moved around. This could be used as a tv/film prop or upcycled into something else.It is large and weighs about 80kg, collection only from Macclesfield, Cheshire, UK.http://www.ebay.co.uk/itm/302006553896?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649PM me here or call on 07842928610

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 17, 2016, 09:20:41 am
content: BTW I saw some of the Grass Instruments kit, hooked up to a PDP8 at the Computer History Museum when I was in SF

author: StuUK
author_rank: Frequent Contributor
timestamp: June 17, 2016, 09:28:08 am
content: How do we know you're not lying about its working state, can you hook yourself up?

author: dexters_lab
author_rank: Unknown
timestamp: June 17, 2016, 10:09:59 am
content: Quote from: mikeselectricstuff on June 17, 2016, 09:20:41 amooh interesting, the rack looks like it has the 'EEG Amplifier for Data Processing' modules that are installed in mine, was there any mention about what the setup was used for?Quote from: StuUK on June 17, 2016, 09:28:08 amlol!i would have tried if i had some electrodes

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 17, 2016, 11:08:50 am
content: Quote from: dexters_lab on June 17, 2016, 10:09:59 amdon't recall the details - think it was a general "computers in medicine" type exhibit.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 18, 2016, 02:03:10 pm
content: Nice looking machine.At least that one was saved. Unlike the one below, which along with a *lot* of other cool old medical and general electronics instruments were left to rot in a set of rooms in a disused building in Sydney. That was in 2009 and the building has since been gutted, so almost certainly they were all destroyed.After I came across them I tracked down the person responsible for the building and asked about salvage. Typical bureaucrat - too hard, didn't know what paperwork would be needed, worried about liability, blah blah blah. He hadn't even known they were there, and didn't give a sh*t about such things.Edit: looking at the pics again now, I notice that in the middle two there's a slide rail pair as used on Tektronix 7000 series rackmounted scopes. And some dumbarse has pulled out the scope (with its part of the sliderail) and left the remainder in the rack. This is something that I particularly despise, because it's so stupid, and yet it *always* happens. Every ebay Tek R7xxx scope you'll see is like that.Except in the R7903s I have, since I got to take them out of the racks myself.Anyway, Mr Graeme Loy, I hope you burn in Hell.

author: dexters_lab
author_rank: Unknown
timestamp: June 23, 2016, 09:54:00 am
content: Quote from: TerraHertz on June 18, 2016, 02:03:10 pmwow, some nice looking kit in there, it's a shame stuff like this goes to scrap

author: dexters_lab
author_rank: Unknown
timestamp: June 23, 2016, 10:00:45 am
content: now also listed on ebay UKhttp://www.ebay.co.uk/itm/301993972053?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 23, 2016, 10:23:41 am
content: Quote from: dexters_lab on June 23, 2016, 10:00:45 am"May not post to New Zealand"I wonder why Ebay UK thinks I'm in New Zealand

author: dexters_lab
author_rank: Unknown
timestamp: July 06, 2016, 02:56:17 pm
content: new auction starts at £1 no reserve!!http://www.ebay.co.uk/itm/302006553896?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

author: Gyro
author_rank: Super Contributor
timestamp: July 06, 2016, 09:26:38 pm
content: I can't help thinking that I should say something profound about the price of truth, but I can't think of anything!

author: dexters_lab
author_rank: Unknown
timestamp: July 06, 2016, 10:32:30 pm
content: Quote from: Gyro on July 06, 2016, 09:26:38 pm'Blair' seems poignant for today