Quote: Originally Posted by
blk02si 
Are you powering the radio with the M4? If so don't, the HD tuner has built in line filtering. Usually poor reception has to do with antenna issues or poor grounds. Can you give more info or perhaps a wiring diagram about how your m4 and tuner are wired?
I've tried powering the HD radio both from the M4 and without... I'll leave it powered seperate from now on.
I have my stock radio still wired and using AUX for my sound input in my car. My stock radio also gets poor reception when the M4 is powered while the HD Radio for the PC doesn't get anything.
I have my M4 powered to the battery with a 4 gauge power run and grounded in the trunk with another 4 gauge cable that I sanded down a 3" area and screwed a gold plated 2" ring adapter. I have all the connections soldered so I know they are getting good contact.
I had the tuner run from the hard drive power from the M4 and grounded on the same terminal in the trunk. I've run the tuner to a seperate 12v source but even so, as I said above my factory stereo is also getting interference so I feel like the M4 is producing it
I don't know where else to ground it... I'm getting the same voltage at the M4 as I am at the battery so I feel like there shouldn't be any resistance from the ground. Should I run more than one ground to the M4?
Oh and the antenna I am using for the HD Radio is a low profile powered antenna that works great without the M4 on.
It's definately the M4 as I have used a normal power supply plugged into an outlet and everything worked.