Sell (EU) OHM converter PCBs for HP 3450A /B Multifunction Meter

[madao]

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 )


Thanks
Matt

[DuPe]

What a beauty.
I whish you success

[Dr. Frank]

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   

[TheSteve]

Hope you can find your board.

A 3450B is on my wish list.

[PaulAm]

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.

[madao]

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

[Dr. Frank]

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.
(Attachment Link)


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

Sorry, 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   

[madao]

Yes, i can remember you with Agilent 34401A in bag with accu  & AC Inverter :-D

[Dr. Frank]

No I was that other tall guy, with 10k and 10V reference only 

[madao]

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.)

Greetings
Matt

[madao]

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)



Greetings
Matt

[madao]

New topic about this card

https://www.eevblog.com/forum/projects/new-designed-hp-3450ab-ohm-converter-card/new/

[madao]

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.

[madao]

Two  PCB (new revision) left.
One running ohms converter (old PCB rev.) left.