Wireless FM Modulators

Hi folks, did a search on this and nothing newer than 2004.  I installed an LCD TV in my RV and am trying to get the audio to play through the Pioneer audio system.  The TV and audio head unit are about 15' apart so it's not practical to used a wired modulator or run audio inputs.  I got this Audiovox unit, but the sound is terrible, no matter what frequency I select:

I soldered about 3' or so of  #16 wire onto the end of the little antenna wire and still get lots of static.  If I move the unit closer to the head unit temporarily, the sound gets better, so I suspect this unit just doesn't have the range to go 15'.  Anybody know of a better unit with better range?

Thanks, I saw the Myron and Davis unit.  Problem with these things is finding the specs on effective range, etc.  I may order it and give it a try, see if it's any better than the POS I have.

Since the last thread on this topic was from 2004, I was hoping somebody had come out with a new piece of HW that solved these issues but I guess not....

I just downloaded a report commissioned by the Nation Assn of Broadcasters complaining to the FCC of these devices overmodulating and exceeding established broadcast limit levels assigned by the FCC.  There are several cited in the report that have no FCC ID labels and claim a range of 150', which is illegal.  The report is in .pdf, PM your e-mail address and I'll send it to you if you are interested

My first reaction was to pick the one with the longest range, but I don't want to P-off all my fellow campers in the campground beacuse I am stepping on their FM signals.....