jdelange said:
I had the same idea... I ran 25' of cheap coax to the window in my room and mounted the RH77CA. No improvement. I monitor pretty much the same frequencies. I am going to buy a right angle adapter today and try that.
The problem with running cheap coax is that you won't improve, in fact you will degrade your reception. The antenna needs a ground plane because it is designed to be attached to a radio, getting sufficient ground plane characteristics from the radio case. At the end of a piece of coax, you need radials because the antenna will now "look" like just a piece of wire and not work at the designed frequencies efficiently.
No adapters, just cut some lengths of wire, a couple for each range of frequencies you are interested in (approximately 7 inches for UHF, 19 for VHF and 3 for 800) then strip back an inch or so of insulation and solder them to an alligator clip and attach it near the base of the antenna where the coax is connected. You will get improvement. All you'll need to do is snip a little wire off (1/4-1/2") to get some improvements in reception quality.
Outdoor antennas actually work better than those indoors. A simple mag mount antenna outside on an air conditioner will work wonders.