Step Recovery Diode Alternative

Hello.
I need a step recovery diode for a particular circuit which requires a 50-70ps of transition time.
SMMD840 from metelics is the one to be used.

Unfortunately this diode is not available in the majority of online stores and Macon does not sell them directly to the consumer.

Anyone knows where I can get them?

Also does anyone know an alternative diode which can fit the requirement of 50-70ps transition time?

Thanks in advance.

Microsemi have an offer of SRD, and I think some of them are available at DigiKey or Farnell

https://www.microsemi.com/document-p...s-datasheet%20

try ebay

https://www.ebay.com/itm/2x-2D524A-R...YAAOSwtfhYsFZk

Lots of old stock supply from Russia

I was about to pick the russian alternative in ebay when I found Richardson electronics have them for a decent price.
Great.
Thanks to you all for the help.

Richardson is a respectable place. They stock all sorts of RF stuff, so even if the manufacturer no longer has it....there is a chance they have some stock on it.