Re: [amsat-bb] Re: Downconverter drift

["Edward R. Cole" <al7eb@xxxxxxxxxxxxx>]

>>I have been very pleased with the frequency stability of my downconverter
>after I soldered a 60C PTC thermistor to the L.O. crystal.  Drift is
>negligible 5 minutes after I turn it on.
>
>I wrapped my 3733 in two layers of tin foil (shiny side out),  and 
>saw a marked improvement in stability after 30 minutes or so.  I also
>mounted the downconveter *under* the c-band feed of the dish,  for
>whatever that is worth.

I ran my Drake [converted to 433.832 MHz IF] for a few hours on the bench
[constant room temperature] and after about a half hour of 50 Hz initial
drift it didnot move more than 1-2 Hz.  The test signal was from a
commercial generator [2ppm] at 800 MHz being tripled by a diode.

Ed


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