[time-nuts] LN RB

[AC0XU (Jim)]

John-

The LNRB had been powered on continously for several weeks prior to my tests. Also, the same antenna/LNA is feeding multiple GPSDOs (4 others) with Lady Heather connected and running continuously, and none of them exhibited any kind of strange behavior at the times of the anomalies in the LN RB timing.

It certainly appears that Jackson Labs did not design the LN RB to be stable in the presence of external temperature fluctuations. To be useful, this seems to imply that it needs an external environmental temperature control. Furthermore, it doesn't seem to be stable near the top end of its supported temperature range even when the external temperature is constant, so the external temperature needs to be fairly low (probably under 40C or so). One application I was interested in is a low SWaP timing reference for smallsats. Its sensitivity to temperature seems to make that application unlikely, because adding external temperature control would make the electrical power prohibitive, even if size and weight can be kept under control. As a lab reference, I expect I can implement an external temperature control and it may work well enough. Overall, I am very disappointed with the product. I have written to Jackson Labs about my concerns but I have not heard back from them.

Jim