Sell (EU)  OHM converter PCBs for HP  3450A /B Multifunction Meter - Page 1
Forum section: electronics / general

author: madao
author_rank: Frequent Contributor
timestamp: July 01, 2021, 04:14:39 pm
content: Hello People.I got a HP 3450A without OHM-converter.Have someone a HP 3450A /B with this two card (and a piggyback PCB).?I need good photo from 3 PCB (bottom and top) for redrawing of PCB.(or good scan of 3450A/B service manual, avaible manual is very terrible )ThanksMatt

author: DuPe
author_rank: Regular Contributor
timestamp: July 01, 2021, 04:56:01 pm
content: What a beauty.I whish you success

author: Dr. Frank
author_rank: Super Contributor
timestamp: July 01, 2021, 08:45:41 pm
content: Nice instrument. Price with all options was > 5000$ in 1969.There's a reasonably good quality manual for the 3450B available online, including the Ohms schematic and PCB.Frank

author: TheSteve
author_rank: Unknown
timestamp: July 01, 2021, 09:23:10 pm
content: Hope you can find your board.A 3450B is on my wish list.

author: PaulAm
author_rank: Frequent Contributor
timestamp: July 02, 2021, 12:30:22 am
content: Given the schematic, parts list and some pics it might be possible to build a replacement.Took me over a year of hard looking to find a 3450a. They are very impressive instruments.

author: madao
author_rank: Frequent Contributor
timestamp: July 02, 2021, 12:57:04 pm
content: Problem: this 3450B Manual scan quality is terrible. I can follow trace and understanding about schematics , but no readable letter on edge connector and Timing-signal.This 3450A was in east germany (GDR ), used by DAMW (GDR metrology insitut )My topic about HP3450A (sorry, german )https://www.wellenkino.de/557/viewtopic.php?f=4&t=451

author: Dr. Frank
author_rank: Super Contributor
timestamp: July 02, 2021, 02:24:31 pm
content: Quote from: madao on July 02, 2021, 12:57:04 pmSorry, I also got this bad copy.madao, I think that we met each other at Maker Faire 2018, at the PTB or Wellenkino booth?There's a nice photo together with Henrik V ..Frank

author: madao
author_rank: Frequent Contributor
timestamp: July 02, 2021, 02:42:38 pm
content: Yes, i can remember you with Agilent 34401A in bag with accu & AC Inverter :-D

author: Dr. Frank
author_rank: Super Contributor
timestamp: July 02, 2021, 02:47:39 pm
content: No I was that other tall guy, with 10k and 10V reference only

author: madao
author_rank: Frequent Contributor
timestamp: July 03, 2021, 03:54:51 pm
content: Ah mei (bavarian oh my god ), this guy with 34401A in Bag is called peter. I am not sure, are you with old fluke 10v reference ?a good news, i got few useable pictures from a youtuber with HP 3450B.But this card has difference to avaible 3450B schematic. (Photo shows logic array is Signetics-TTL, schematic tells DTL)1820-0094 & 0096 is old DTL and 1820-0303 and 0320 is Signetics TTL. Pinout vs S-TTL and DTL: just mirrored.Despite difference logic IC: Fog about edge connector goes slow away . I have written youtuber, i need yet photo of bottom PCB. (yet unkown about timing signal on rear/bottom edge connector.)GreetingsMatt

author: madao
author_rank: Frequent Contributor
timestamp: August 07, 2021, 07:44:57 am
content: New draft with modern parts is successful.Only high restiance range is not very well, probably uncleaned pcb (full solder flux )I have four PCB left (came from jlcpcb), i give it for shipping cost and donate away (of coruse, include copoment list and schematic)GreetingsMatt

author: madao
author_rank: Frequent Contributor
timestamp: August 08, 2021, 05:56:44 am
content: New topic about this cardhttps://www.eevblog.com/forum/projects/new-designed-hp-3450ab-ohm-converter-card/new/

author: madao
author_rank: Frequent Contributor
timestamp: January 04, 2022, 04:29:40 pm
content: I have this first running board left (added with SO-DIP Adapter and OPA202 ), i would sell him for 20€ (compoment is not cheap, reedrelais and DCDC converter) and shipping from germany. Because: i have designed pcb newer revision with improvement (minor) and it has replaced old converter.4x PCB (newer revision) ist free, only shipping cost. ( second version of PCB with few minor improvement)1x old(first) running complete PCB 20€ and shipping cost.

author: madao
author_rank: Frequent Contributor
timestamp: January 05, 2022, 04:03:52 pm
content: Two PCB (new revision) left.One running ohms converter (old PCB rev.) left.