FYI, I found a source for the PLCC44 version of the STEL-1173 that's used in some Datum FTS Cesium standards. I got mine from here: http://www.aliexpress.com/item/Free-shipping-10PCS-STEL-1173-CM-PLCC/2023682701.html I left positive feedback, not sure why it doesn't show. Shipping was very slow, but the chips appear to be NOS. There are no scratches on the leads which suggests that they were never installed in a socket. I was having trouble with one so I decided to sacrifice it to see what was inside it. The die is labelled 'ORBIT B-100'. When I chopped out the dead chip from my FTS-4065A, the bottom was stamped with the word ORBIT. ORBIT Semiconductor works on FPGA to ASIC conversions. It looks like Stanford used Orbit as a fab house. I'm currently measuring my 4065A against my Tbolt. After about 37 hours, I'm still not seeing anything that I can attribute to the 4065A. All I'm seeing is the Tbolt and the typical response that every GPSDO gives. I'm looking at Total Deviation values of around 1E-13 at 100Kseconds. Frequency offset error appears to be about 6E-13. All diagnostic status values are within spec. I had to adjust the signal level from the tube - it was too HIGH! I decided to solder in a socket so that I won't have to go through any pain if this chip dies in the future - and I now have spares! Ed

Are you sure you are measuring the 4065A against the Tbolt? TBolt feeding the start and 4065A feeding the stop and a counter in time interval mode? On Fri, Nov 14, 2014 at 3:26 PM, Ed Palmer <ed_palmer@sasktel.net> wrote: > FYI, I found a source for the PLCC44 version of the STEL-1173 that's used in > some Datum FTS Cesium standards. I got mine from here: > > http://www.aliexpress.com/item/Free-shipping-10PCS-STEL-1173-CM-PLCC/2023682701.html > > I left positive feedback, not sure why it doesn't show. > > Shipping was very slow, but the chips appear to be NOS. There are no > scratches on the leads which suggests that they were never installed in a > socket. I was having trouble with one so I decided to sacrifice it to see > what was inside it. The die is labelled 'ORBIT B-100'. When I chopped out > the dead chip from my FTS-4065A, the bottom was stamped with the word ORBIT. > ORBIT Semiconductor works on FPGA to ASIC conversions. It looks like > Stanford used Orbit as a fab house. > > I'm currently measuring my 4065A against my Tbolt. After about 37 hours, > I'm still not seeing anything that I can attribute to the 4065A. All I'm > seeing is the Tbolt and the typical response that every GPSDO gives. I'm > looking at Total Deviation values of around 1E-13 at 100Kseconds. Frequency > offset error appears to be about 6E-13. > > All diagnostic status values are within spec. I had to adjust the signal > level from the tube - it was too HIGH! > > I decided to solder in a socket so that I won't have to go through any pain > if this chip dies in the future - and I now have spares! > > Ed > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.