The 4228 is a UHF antenna, for TV channels 14 and above. The 4228 is also very directional. The FM band lives between TV channels 6 & 7. It might work for some FM stations but I'm guessing you will be less than thrilled with the results, especially if the FM transmitters are not in the same general direction as TV.
I'm in a bad location for FM and TV, and use a 4228 mounted about 5 feet higher on the same mast as an omni-directional FM antenna, with mostly good results. From my reading here it's important to maintain as much seperation between the two antennas as possible.
The easiest way would be to just use a splitter. You would get all signals at both outputs. I don't know what sort of FM reception you would get from the CM4228 since it's a UHF antenna and is completely the wrong sort of design for FM (band II VHF) but who knows, you can get FM radio with almost anything, I guess you can just try it, a splitter is only a couple of dollars...
please don't attempt to use the 4228 for FM reception, it just will not work well since the active elements are cut for UHF frequecies, not low band VHF. The difference in element lengths can be in "feet". Splitting your coax feedline from the 4228 will also reduce the overall signal available to the TV set. It is just not worth the effort.
A simple FM turnstile style antenna ($20 - $30) with a separate feedline will give you much better service and reception.
haha, I just tried this, surprisingly, it actually works pretty well. I got some stations from all over the place, but only the opposite direction of the antenna to about 50 miles, one is about 80 miles away. Where it was pointed I got a few Montreal stations, which is 140 miles away. It works a heck of a lot better then that little "thing," I won't even call it an antenna that came with my receiver.
I didn't split it, just moved the antenna input from the TV to the radio, both are very easy to access and I figured that I'd never use both at the same time, so why trouble with the signal loss
Or, you may want to use a drop amp 18 dB gain to boost the signal first, then split it into 2 port: one for TV, one for FM receiver?
A Philips multimedia drop amp can be found at Princess Auto (hopefully there is one in MTL) for a mere $5 if they still have stock (or a Cdn Tire version would work too). You go this far, why not take one step further ?
Can you split the one line coming off the antenna to feed both OTA into D* box and run other line to FM antenna input on a reciever???
If so what do you use to do this.
You can use a good splitter, or a 2 port dist amp to overcome signal loss. Or a dist amp and a 2 port splitter, or an A/B switch. But the 4228 is not designed for FM, but it still may receive some signals as well as HiVHF. But I use basic rabbit ears from Radioshack and get very good FM reception from 75-80 miles, which should work better. Or an omni FM antenna from Antennacraft or Winegard would be even better.
Using the Channelmaster CM4228 will work for FM, but not all stations will come in clearly. If using for HD radio, then it's recommended to use an FM antenna, as digital signals work best with an antenna optimized for a specific frequency range (in this case, FM being 88.1 & 107.9 mhz). I wonder if the OP is from Boston, as the Boston stations are all UHF, though some VHF signals from New Hampshire do cover Boston