Re: Anybody have some good hints to tame frequency drift on 6M.

HF
 

Hi Dave

Another matter to consider:  When the U3S starts transmitting, its finals warm up and the heat dissipation of other components in the circuit changes, too.  The TCXO will adjust itself to hold its frequency as well as it can.  I'm amazed at how well that is, but it's still not perfect.  To slow down the TCXO's temperature changes, I mounted it on 3 very thin wire strands, about 2 cm above the board.  Then I stuck a piece of foam under the TCXO.  Those wires take a little longer than PCB foils would take to conduct other components' heat to the TCXO.  But they become inadvertent antennas.  My U3S is now inside a metal enclosure which somewhat contains that radiation. 

Cheers

Halden

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