Sometimes you have to work at it to get some activity, rather than just listening.
If you are in the shack, announce your call every hour or so even if this nets nothing for a week or more.
If you've got some free time, put the word out on qso's on other bands that you'll be up at RF-Mount for an hour at noon or whatever - even if just mobile / portable and put out some calls. Make it a regular thing, and perhaps others will join you - even if just for an hour every weekend or so.
If people hear of success, and it seems to be kind of a regular thing / rotating op or locations, that might get the ball rolling with the inexpensive radios at least.
You never know - it may be a lot of work for nothing. On the other hand, I've seen it just burst with activity once people know that someone is actually out there on a semi-regular basis. Out come the radios from the closet, or even new ones. Scaled up, this may turn into a repeater with group support.
But it takes work sometimes.