40 Meter VXO Design For VRX-1

Finished initial tests for the 40 meter vxo/osc design this morning. Not done with all tests as I want to look at the circuit that George, G3RJV used for his Universal VXO. What I did complete this morning allows me to swing from just under 7.00 Mhz to 7.037 Mhz in a linear manner and still being able to maintain a stable signal source. I need to put it on a dedicated piece of PCB board and mount it on the VRX-1/NS-40 rig and interface it to each.

Due to interaction of two of the inductors, a bit of playing around with it will be necessary to get it exactly where I want it to be (freq swing range). I used two 7.040Mhz xtals, three molded inductors (2, 18 and 20Uh) and a 260pf poly variable cap. The 2 and 18uh inductors lie side-by-side to allow interaction for a larger and more uniform swing.

I hope to try winding some roids this evening to see if I get the same results. Will post schematic and additional info on my web site later.



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