Hello all,
I have got a broken HP 4192A LF Impedance Analyzer. After some trouble-shooting it became clear, that the line filter must be the culprit. I can measure basically 0 ohms between the line and neutral.
HP used an EMI filter made by Corcom with the part number 9135-0084.
L = 2x(7+7) mH
R = 10 MOhm
Cx = 3x270 nF
Cy = 2x2.8 nF
Unfortunately I could not find the datasheet or any further information. I want to replace the filter with a new one (no new old stock, because it is unclear, if the capacitors already degraded from usage or just storage). But I could not really find a direct replacement.
The distance between the mounting holes is approx. 75 mm, the filter dimensions without the mounting plates are approx. 63 mm length, width approx. 50 mm and a depth (thickness) of approx. 40 mm. Smaller is as well perfectly fine (except the distance of the mounting holes). The connection is done via 3 input wires (L, N, earth) and two output wires (L, N). If possible, I would stick to a solution with wires (faston connectors could be possible as well).
HP specifies a 1.25 AT or 0.6 AT fuse, dependent on the line voltage setting, hence I think a filter capable to handle >2 A should be fine.
The only EMI filter I came across so far is the FN2090-3/FN2090-4/FN2090-6 by Schaffner (ideally with order code -07 for the wired variant), that should fit mechanically in the HP. The values of the filter components do unfortunately not really match and it got another pair of Y capacitors.
Does anyone has another suggestion as a replacement or maybe could give a couple of hints regarding the proposed selection? Is there something else to watch out (current rating of more than two times the fuse rating is fine)?
Thanks.