OCXO drift with U3S #u3s #ocxo

Sverre Holm

I just assembled an OCXO and have had it running for a few days with the U3S at 18 and 14 MHz. The U3S is in the QRPLabs enclosure. It turns out that I need to have the lid off in order to reduce drift to 0. Otherwise I will get drift in the -1,-2,-3 range. This seems to indicate a heating problem, could it be that it gets too hot with the lid on?

And how should I interpret the drift? Does it mean that the 27 MHz reference is drifting down in frequency during the transmission with about 27/14 times the reported drift? Could it be that I haven't found the proper sweet spot for the setting of the OCXO?



LA3ZA, http://la3za.blogspot.com

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