Repairing a probe


The probe tip


All parts

One of my Hameg probes stopped working. Often is the only solution to buy a new one. To my surprise the Hameg probes are reparable. The wire in the coax was broken just outside the probe. The coax ends in a modified bnc adapter. The construction is a bit simple. The compensation network is at the other end of the cable.

The inner conductor of a good scope is just one strand of very thin wire. So be careful not to apply mechanical force to a probe.

I used to have a few cheap Chinese probes (2 Teks and 2 Rigols) that died within a year. I tried to fix them without result so I was surprised the Hameg turned out to be repairable.


Hmm, not a good month for probes:

A broken Tek probe

A broken Tek probe

My favorite Tektronix probe died. One of the compensation trimmers dropped of the pcb. It turned out to be repairable too. This 100MHz probe has a PCB inside. With a Dremel I cut of the crimped part to get acces to the pcb. Cut a few cm of the cable and soldered the shielding all around to the probe body. After that it worked like before.

And a day later my Philips followed. Here the inner conductor was broken just outside the prob body. This one was a bit harder to fix. The probe is more service friendly but not the cable part because the cablepart is rather small and hard to get grip on it to dremel without damage and get the cable out. Mouning was not so hard as I thought. I soldered a new crimpbus from a thin bnc connector to the body and crimped it to the cable.

A Philips probe

A Philips probe


Its guts exposed

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