I have an MKIIa with tuner installed in my car as well as a HD Radio head unit. Unfortunately the tuner and the HR Radio do not have very good FM reception. I’m thinking the problem may be the fact both the tuner and the HR Radio are using the same antenna (I have Y cable).

Would a signal booster work to improve reception?

In the old days you could tune the FM receivers by tweaking the trimmer cap. I don’t see that as an option with this new fangled stuff.

I probably should have asked the brains here years ago but I really don’t listen to the radio too much.

Any ideas?

What's the reception like if you remove the Y and connect only one unit?
If OK then a booster might help, if not it'd probably just be amplifying garbage.

It's not the case that your antenna is supposed to be fed power, by separate wire or via adapter over the coax, and that isn't currently provided?

I knew someone would ask if reception would be better with only one tuner connected. To be honest I haven’t looked into that. I know the original factory radio worked OK, the first empeg tuner worked OK (actually pretty good until the tuner module died) and now both tuners don’t work very good. Guess I’ll crawl my fat ass under the dash and disconnect the Y to be sure.

I never really gave much thought to RF boosters. I always put them in the snake oil category. Maybe if they just separate the tuners from each other that might be enough to make things better,

There is no power of any kind going to the antenna. It’s just a plain old wire antenna on an older (but nice) Jeep.

As Michael says, the only use for a booster is for a weak signal. If you have a crap signal, you'll probably only get a stronger crap signal. This can help with digital sometimes though