[NLRS] Freq stability improvement

[Bill Davis]

   Thanks to DEMI and a lucky draw at MUD, I was a "lucky dog" at the prize table and came home with a DEM L144-28INTCK kit. This is Steve's 2m transverter that is designed for use with higher band/microwave transverters with 144MHz IF. Part of the incentive for selecting the transverter was  limited "good" choices at the time my number was read AND I had not built any DEM gear in a very long time. The new designed transverter would be a fun project and with some input level mods for 902/1296 and 10GHz, would be something new in the shack. One of the "new features" of this design, is an improved Xtal heater and insulated enclosure for the osc. (Important for what follows)

   I built up the new transverter this past week, a very nice kit and modified the transverters to allow lower drive levels (prior 1-2W on all). All bands seem to be playing well. Yesterday I started to wonder, I wonder how much of my 902/1296/10GHz freq stability issues while attempting WSJT in the past on those bands, were associated with the older designed 25W DEM 2m tansverter that I was using, as the 144Mhz IF? Answer, MOST if not All! This morning Gary and I ran WSJT on 10GHz and 902 with VERY good freq stability. Gary is GPS locked on both bands. We didn't try 1296, the older DEM designed 1296 transverter may be stability challenged, we will see. But 902 and 10GHz was doing well. Solid copy on 902 and one good decode of Gary on 10GHz. What appears to be multipath coupled with the very weak sig on 10GHz didn't allow much more in out brief quick test. We were using WSJT JT65B, the same mode as we use with 2m WSJT EME.

  More will follow as we make other tests. A FUN few min added to our regular twice daily sked. Thanks Gary!


  Thanks also to Steve for the nice items on the prize table AND the osc stability.

73  Bill   K0AWU