I've used thumb tacks (aka, push pins) to hang J-poles on the inside of exterior walls. Works fine. Just try to make sure there is no electrical wiring in the wall where you hang the antenna (no light switches or outlets in the 16" wall span where you hang the antenna). Windows can work, too, but there's a chance of metal in the window frame upsetting the quarter-wave portion of the antenna, which is a transformer.I just used a push pin and hung it over my sliding glass door so that it had a clear view out the window.