HP 180A rack mount Oscilloscope repair/restoration - Page 1
Forum section: electronics / repair

author: MCRodrigues
author_rank: Contributor
timestamp: March 20, 2015, 05:11:13 pm
content: Hi everyone!I just got a 180A Rack mounted Oscilloscope with 1802A 100MHz vertical amplifier and 1822A time base plugins.This scope was made on late 60's, early 70's, using solid state discrete technology (no vacuum tubes except of the CRT of course...).Unfortunately comes with no probes nor manuals to service it. Only with 30 years of cumulated dust...The guts are kind of OK.. but has some magic smoke marks on the chassis between the vertical amplifier and CRT. I heard that the owner tried once to repair it but was left slowly dying in an old attic.So this old grandpa needs some care. Will take some pictures after some clean-up.I've found the Mainframe manual on the Net but for the plugins nothing....Does someone have manuals for each plugin or do know where do I can get some?Here are some documents that I found related about this scope:HP 180A Manual -http://bee.mif.pg.gda.pl/ciasteczkowypotwor/HP/180A.pdfHP 1802A Manual - Couldn't find any...HP 1822A Manual - Couldn't find any...08-1966 HP Journal -http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1966-08.pdfBrochure -http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=5217101The 180 System -http://www.radiomuseum.org/dsp_multipage_pdf.cfm?pdf=usa_hp_180_oscilliscope_system~~1.pdf

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 21, 2015, 01:04:32 pm
content: :Those manual seem to be hard to find. I found a reference to Tucker having one and there's always ebay + patience.You could check the hp yahoo group. There's a project underway to scan a whole pile of manuals; there's a chance those might be in there..

author: MCRodrigues
author_rank: Contributor
timestamp: March 21, 2015, 10:46:35 pm
content: Thanks for the tip!Will check that out.I searched across internet, using many search engines and couldn't find anything, except on ebay of course...Got some quick pictures of the scope with my cellphone. Sorry for how crude they are...

author: MCRodrigues
author_rank: Contributor
timestamp: April 15, 2015, 01:42:01 am
content: Quite some time that I don't give news about it.Here is a dropbox link with picture dumps and current status about this restoration.https://www.dropbox.com/sh/477dbk4ukjrujh5/AABvrrOROHas3t2HYo5pCfvia?dl=0Right now the scope is completely disassembled. Got everything cleaned, but can't take out the tube. The suction cup is really hard and can't squeeze it. The neck connector is stuck. Noticed that some pins on the connector where soldered. Is it should be like that or I have to unsolder them?Best regards!!

author: MCRodrigues
author_rank: Contributor
timestamp: November 18, 2015, 05:03:27 pm
content: Hi. Some passed since my last post. I've been kind of busy but now the project is being resumed.The dropbox link has been updated. New picture dumps where added to the visual log.https://www.dropbox.com/sh/477dbk4ukjrujh5/AABvrrOROHas3t2HYo5pCfvia?dl=0Current status:Everything is now cleaned up and being put back together. There is a problem then. A filament from one of the neon lamps on the high voltage circuit board (Logs/2015-04-11/20150412_123832.jpg) has broken just at the edge of the glass. I'm not sure but according to the service manual schematics and from a post that saw, these bulbs are being used as voltage clamps.https://www.eevblog.com/forum/testgear/hp-180a-oscilloscope-neon-bulbs-in-power-supply/Here is the datasheet of the bulb A9A-C (NE-2E1):http://www.mouser.com/ds/2/423/Neon%20Indicator%20Lamps_7___8-552457.pdfWhere can I get those neon lamps in Europe, or can I put different kind of lamps?Mouser have those A9A but the shipping cost is too much for just for a couple of them.Best regards.

author: rf+tech
author_rank: Frequent Contributor
timestamp: November 19, 2015, 02:10:38 am
content: Hello,Unless I am mistaken, I believe the HP 180 is the rack mount version of the HP 182.At least, these two models should share a lot in common. The good news is that the HP 182 manuals can be found here:http://www.ko4bb.com/manuals/index.php?dir=HP_Agilent/HP_182Most any neon lamp should work in the voltage clamp circuit, typical firing voltage would be about 95 Volts dc.Best Regards,

author: MCRodrigues
author_rank: Contributor
timestamp: November 20, 2015, 09:21:50 pm
content: rf+tech, its been a while trying to know if it could be done.The device is now fully assembled. I've just ordered the neons and a couple of UNI-T ut-p05 probes to test the gear. Lets just hope that it will not blow apart.Best regards.