Solartron 7075 Schlumberger Digital Voltmeter - Needs Work - Page 1
Forum section: electronics / beginners

author: p.larner
author_rank: Frequent Contributor
timestamp: December 30, 2023, 08:31:39 pm
content: Waiting on this to arrive,ebay item no:266562163509,what is the displays used in these,i think its called a panaplex or something,is it like an led 7 segment jobby but using neon buld type elements in it?.,could be fun.

author: tggzzz
author_rank: Super Contributor
timestamp: December 30, 2023, 08:58:59 pm
content: The usual....Replace FIFAs.Check all voltages for mean value and ripple.Repeat all connectors, especially the grotty ribbon cables.

author: p.larner
author_rank: Frequent Contributor
timestamp: December 30, 2023, 09:05:17 pm
content: yup doing what you said is par for the course,will know more as it should be here on tue,i was more interested in the displays as they seem to be some weird things that run on 100+ volts,but not a vfd job or nixi or filament indicator!,i think if there dead i am stuffed,doubt they will be dead tho.

author: Gyro
author_rank: Super Contributor
timestamp: December 30, 2023, 09:10:47 pm
content: Yes, they're Sperry / Beckman / Babcock Panaplex displays, Neon planar 7 segment, probably the 1/2" 35x series. Anode supply is typically around 180V. You'll find info on the web.

author: tggzzz
author_rank: Super Contributor
timestamp: December 30, 2023, 09:12:16 pm
content: Quote from: p.larner on December 30, 2023, 09:05:17 pm180V PSU, but IIRC about 140V across the Panaplex displays.But don't guess, RTF(service)M.

author: Gyro
author_rank: Super Contributor
timestamp: December 30, 2023, 09:18:38 pm
content: I linked the manuals in your abandoned thread on the same meter here...https://www.eevblog.com/forum/beginners/test-gear-questions/msg5235444/#msg5235444

author: p.larner
author_rank: Frequent Contributor
timestamp: January 01, 2024, 12:49:14 pm
content: well i started testing the psu caps,there is one c119,its marked 1uf electrolytic@250v,it reads about 6 ohm esr and 1.6uf,is that bad?,if so can i replace it with 2x polypropalyne types of 2uf 260v in series?.

author: ArdWar
author_rank: Frequent Contributor
timestamp: January 01, 2024, 01:13:07 pm
content: Quote from: p.larner on January 01, 2024, 12:49:14 pmNo? That's even remarkably good ESR for a very old electrolytics.Quote from: p.larner on January 01, 2024, 12:49:14 pmPut one, no need to put them in series. It doesn't matter if you put 1uF or 2uF there, or maybe even 10uF. It's just bulk caps, anything close is fine. Just don't go overboard with your values in case it may mess with power sequencing.

author: tggzzz
author_rank: Super Contributor
timestamp: January 01, 2024, 01:23:02 pm
content: Quote from: p.larner on January 01, 2024, 12:49:14 pmGoogle is your friend. It leads tohttps://www.eevblog.com/forum/beginners/esr-values-for-electrolytic-caps/

author: p.larner
author_rank: Frequent Contributor
timestamp: January 02, 2024, 05:34:34 pm
content: As this came with no test lead connector,the original 5 pin test lead plugs seem almost impossible to get and the ones ive seen are over 100 pounds sterling,i was thinking of using binding posts but is there any reason i cant replace the original test lead socket with a 5 pin din socket like this ebay jobby?https://www.ebay.co.uk/itm/311641980101?epid=1704294552&hash=item488f4f3cc5:g:OCsAAOSwPhdU7F5N&amdata=enc%3AAQAIAAAAwA7KgAOEF5G6q%2F9X2nq42vcTES8rXZBLMLU8ZyFb24LXsG2NcNN%2FSQrmr1KDlgSVa%2BgcV4ZoyyIyeDWPo4ZalnfODAcsNwcBtk%2BXaK9oAR5CqHtNA9idYctWZ%2Fa8yzTLR0tuKFNIU4l1RWwv%2Bar5ntXNh9MgSIaRXoN1oDHctT07CmxDD6%2FbmymexFVF%2F%2BcEcgqX966zi0pPKrX9H9zg0UdY9t5tW4Lu%2F5SXRm6OdmYSGiJb5Vlv35qCsht9UXaC%2Bw%3D%3D%7Ctkp%3ABk9SR4z64rOZYw

author: Kleinstein
author_rank: Super Contributor
timestamp: January 02, 2024, 05:45:38 pm
content: The XLR / DIN sockets are made for audio and chances are they are not specified for a high voltage. With so many pins close by is can be hard to get the required distances for isolation.Another possible weak point may be thermal EMF - this may of may not be OK for lower voltages.

author: p.larner
author_rank: Frequent Contributor
timestamp: January 02, 2024, 06:32:00 pm
content: it looks bigger and wider spaced pins so would guess it would be better for high voltage.

author: factory
author_rank: Super Contributor
timestamp: January 02, 2024, 07:03:37 pm
content: https://www.eevblog.com/forum/buysellwanted/group-buy-fischer-connector-plug-s104-a053-130/