[hillpc]

This is getting interesting.

Thanks for all the good input. Small adjustement to rotator helped me get 42 this afternoon (several hours ago). Then later I did some experiments to see if it's the preamp overloading something. I don't think it's preamp overloading (at least not on most of the channels) - here are the results of preamp power supply completely out and in, with the preamp power supply and a converter box and a portable analog TV at the bottom of the 20 foot downlead at ground level. I left the preamp at the antenna up there, as I didn't want to climb up there. I was using the auto channel scan as a poor man's field strength meter:

1.) Mast downlead directly into converter box: real channels 6 and 12 locked in. Repeated, with same results.

2.) Add preamp power supply plus 10 feet of RG-6 between downlead and converter box: real channels 6, 17 (lost 12!), 22, 26, 27, 29, 31, 34, and 35 locked in. Note that 42 still didn’t come in, though I had it this afternoon with this exact setup. Gone now.

3.) Remove preamp power supply to repeat 1.): same results as 1.) above.

4.) Add preamp power supply to repeat 2.) above: same results as 2.) above, except 2 more weak channels added this time, 25 and 32. Still no 42, which I had this afternoon.

Time of day, weather, or something seems to make some kind of difference here. It’s not raining.