Back in 2013 Sergey Kubushyn posted a great explanation of how to build a clone of a Tektronix 067-0681 TD Pulser. It required a specific Russian surplus tunnel diode. While there are always a bunch of Russian tunnel diodes on eBay, the specific one he specified has been impossible for me to find. However, some just appeared on eBay. There is one group of 10 pcs still available and they are quite pricey compared to the other ones for sale at $80 USD for 10 pieces. The prices of the available pulsers make this look reasonable. However if there is anyone else as desperate as I have been to find some they are eBay item no. 323585650249. I hope this helps someone.
Jack Reynolds
