In 2000 I was driving past the Salem, OR airport and heard 4 Seattle Center Controllers talking--presumably three from the Horton site and one from Rex Parrett (Radio Reference). Never usually hear that. Most Centers only use two at most at any one site: either low/mid-high or mid-high ultra-high, never three.
Even with DECODE, apparently most Centers only have one primary site for a freq. They may switch, occasionally, for maintenance and transmitter checks, but there is always a fixed primary. As I learned today in McAlester, OK even though Radio Reference states that 134.475 is on DECODE there, it isn't. It lives at Texarkana as the primary spot. TXK may be the only other that I have heard with low/mid-high/ultra-high located at one rcag; Horton, OR being another.
Thanks for the PDX feed. Do they still allow joggers along the northern boundary next to PDX? Bicycles?
When I was there last, they did, though that was in June. I was staying at a hotel on the other side of the light rail from KPDX and had a perfectly good view of that.
Where is a good place to planespot there? I wouldn't think that the shopping centers further down the street would be a good place to go, but I've only been to that airport twice while heading up to Vancouver or Chehalis.