Long e-mail -QSL with lots of interesting information as follows:
"We have received quite a number of reception reports from your part of the world, so it must be a hot spot for us. Currently we are diplexing on the same tower as the 1480 signal (which is still operating, but must sign off permanently in November after the five year grace period expires) and we think that this setup may somehow be giving 1630 a high angle of radiation which is creating frequent reception where you are. The tower is not exactly the right length for 1630 since it was constructed originally for 1480. After 1480 signs off the air we may remove the diplexing equipment and adjust the tower height to optimize it for 1630. The company is also considering moving the entire site to the 580 WGAC site and diplexing on that tower, but the frequency separation is so great that it may not be practical."