I replaced my 1S1's four sampling diodes with four HSMS-8202 dual diodes, with each part wired to use the two diodes in series to increase the breakdown voltage and reduce the capacitance.
They are marked Obsolete at the major distributors, but Quest Components appears to have a few, as do MiniKits in Australia. There are about a dozen auctions at eBay.
Today I would use the Macom MA4E2054B1-287T which they list as a direct cross-ref. They are in stock at DigiKey and Mouser.
Or the Infineon BAT15, BAT17, or BAT62.
These are SOT-23. I made a little T-shaped "chip carrier" out of bare PCB material that fits in the original clips.
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Jim Ford via groups.io <email@example.com>
Sent: Wednesday, December 09, 2020 2:43 PM
Subject: Re: [TekScopes] 1S1 sampling bridge GaAs diodes: What alternatives?
Although discontinued by Avago/Broadcom, I'm sure. That's the way it
goes these days. They discontinued me and a whole lot of others as
well, as some of you are probably tired of hearing me say!
The HSMS-28XX and other former HP Semiconductor devices just don't have
the volume they once had, and the suits at Avago/Broadcom don't like
that, nor do their investors.
------ Original Message ------
From: "Tom Lee" <firstname.lastname@example.org>
To: "TekScopes@groups.io" <TekScopes@groups.io>
Sent: 12/9/2020 2:31:43 PM
Subject: Re: [TekScopes] 1S1 sampling bridge GaAs diodes: What
I have not actually fixed one this way, but I would expect an HSMS-28xx Schottky to be a perfect replacement here. These are readily available.