A wire up the drainpipe would be quite good but probably suffer from EMC from all the gadgets running in the condo. I suggest two parallel 75ohm coaxes to the roof giving you a waterproof 150 ohm feeder.
Interesting, I had not considered that.
I turned on the radio with a cheapie "10 meter" mag mount hooked up to it. There's a fair amount of RF noise in the place. We shall see how it goes.