Re: HP 5086-7539/5086-6539 SPDT PIN switch - removing SMA connectors from assembly - suggestions? Photo attached
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A while ago I took apart an optical receiver module that I suspect uses a similar connector assembly.
In that device, there's a glass bead pressed into the housing and that passes through to be wire-bonded onto the substrate. Then the 3.5mm centre conductor has spring fingers on both ends, and pushes on to the other side of the glass bead.
The connector shield then threads into the housing, holding in the centre conductor with a spacer tube.
I disassembled it by threading on a pair of nuts tightened against each other, then unscrewing it. It took a bit of force, but not too extreme.
That aside, when you say there's a failed diode on the switch, do you mean the protection diode on the input? If it's shorted to ground, one thing you might try is just carefully plucking off the diode. You can read about a successful repair like that here:
Looking for suggestions as to how I could remove SMA connectors from a HP 5086-6539/7539 PIN switch (used in HP 85046/85047 VNA test sets, possibly elsewhere.)
The photo is of part of one of these switches (known single diode defective, common failure mode, rendering the expensive device a pretty piece of jewelry.) It's replacement is a SPDT mechanical switch (HP 33311B) and a small jumper change on the relay driver board in the 85046/85047 (so that in effect test set option 009 is realized), but getting back to a solid state switch would be more enjoyable (!).
I believe I've reduced the component shown to the minimum; there are no further fasteners, and the metal structure appears to be gold plated (something).
My goal is to see if I can remove the existing SMA connectors, drill to ~3mm the diameter of the three (sub-1-mm) RF paths from connectors to the tiny unobtainium RF circuit module, attach replacement (2-hole bulkhead mount with PTFE insulated section) connectors, and devise a replacement small RF PCB (that might sit on top of the existing dead (and then disconnected) RF section (I've found a 0201-size PIN diode that seems like it would be worth trying, attachment would be via silver conductive epoxy as soldering that tiny is above my (zero) pay grade..
This remake? wouldn't meet any of the original HP specs (particularly isolation), but might be worth a try, at least as a learning experience.
My progress towards this end stopped when I considered that the only way I could see to remove the existing connectors would be brute force, but without an ample supply of these switches (one), I'm loath to try that approach if a better alternative exists.)
So, please take a look, suggest any other image views that might help, and let me know your? thoughts?
Thanks!
Dave
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