¿ªÔÆÌåÓýI was thinking in terms of a beam lead microwave diode ¨C but held back from suggesting it given the difficulty in handling, mounting and soldering/conductive epoxy/lead bonding such physically tiny devices. But given the bandwidth of the 1817A sampler, that would seem to be the only easily procurable (and cheap!) part family. And they have the correct sort of capacitance (0.2pF) and inductance (<250pH) needed. Just don¡¯t sneeze when handling them ¨C and a good stereo microscope is essential. ? Craig ? From: [email protected] [mailto:[email protected]] On Behalf Of Mark Kahrs
Sent: 07 September 2020 03:56 To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP 1817A TDR sampling head ? Salut Jean-Claude: ? The 1817A sampler contains the incredible Grove sampler (see the US Patent, US 3,278,763 for the associated patentese, also see the Proc. IEEE paper by Grove for the theory of operation and detailed analysis).? IMHO, the Grove sampler was the last hurrah for non-monolithic microwave sampler construction.? Since this sampler was found in many HP instruments of the era, you can find repair instructions in the 1430C manual (and others).? Basically, the diode is a pill that is shimmed into contact with the stripline.? To replace this with a modern diode, you're going to have to fabricate a matching mechanical contrivance.? I suggest (without having done this), that you might be able to "print" a suitable diode holder and then insert a replacement diode (it would be tempting to use a beam-lead diode or find a suitable pill diode). ? For extra homework, I suggest replicating Grove's analysis in the Proceedings. ? Bonne Chance! ? ? On Wed, Sep 2, 2020 at 1:09 PM JCB_SFR <jean-claude.bernengo@...> wrote:
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