King/Stirling & trees
Thanks very much for your comments. Indeed, last weekend, I was playing with the switch on the CM7777--->as you were saying, it does have an impact on VHF channels,. Setting the switch to 'combined' allows me to pick up a strong signal on 6.1/6.2 (Global) from my in-attic installation, which is totally absent when the switch is on uhf-only.
We are actually on top of a hill facing in the London direction, so there is some hope of cfpl/london, though I do expect that I won't know for sure until I try it out.
Fortunately, I believe the former owner of our house had an antenna setup at some point...there is a crossbar that has been mounted just below the tip of our (sharp) roof, and that is easily accessible from a step-ladder from a 2nd floor balcony. And, there is a ground rod already pounded into the ground, near the old window that I intend to route the cables into the house from. So, a lot of the heavy physical work is already done for me in advance.
Anyway, I'll try it out, probably when the weather gets a little less icy (don't want to slip off the ladder, after all).
There is hope for improvement anyway, and this is an interesting exercise to try out.
As a sidebar....when I first moved into the area, back in the mid-90s, Rogers was in the middle of providing a 'reverse-option' cable, where they would jack up peoples' cable bills for extra channels unless the customer actively opted-out. Because of this, I vowed never to go to cable again. Up to now, rabbit-ears have been good enough, but with the digital transition, I now know I can do much better.
Finally, I have been seeing a bit of a supply problem with getting rotors these days. I'll have to check the store again (I have been going to Research Electronics, in the N end of Waterloo; it is about a block from where I work).
Thanks for your advice and work in helping people out in this forum! I'll post again with results when I have it all set up (probably later in the spring some time).