I just got my license a week ago. Installed a new VHF/UHF radio in my car and everything seems to be working great. I've been heard at distant locations and picked up signals from repeaters that are way beyond where I expected to reach. However after programming my radio, I noticed that one VHF frequency in particular, 147.000 MHz, got quite frequent interference (by "interference" what I really mean is that when I leave it in memory scan mode, it often stops on that frequency, picking up a signal with no information in it for a few seconds, and then moves on). I've tried to adjust squelch settings and that doesn't help at all, so it really seems to be detecting something. (Unfortunately avoiding this frequency is not an option, as it is a local repeater frequency.)
After about a week I realized a pattern - this happened either whenever my cell phone received a message or whenever the lights lit up on the phone (due to me pressing a button, for example). So it definitely seems like the cell phone is at fault here.
So now I'm looking at ways of mitigating the interference from the phone. Granted, I'm not even sure what should be causing the interference. My first instinct is to add a low-pass filter at the location where the antenna wire hooks into the radio, but it seems like what I'd be looking for is something on the order of a 600MHz cutoff low-pass filter and it doesn't seem like ferrite chokes exist at that high frequency (without attenuating the UHF or VHF signal as well).
Alternatively, I guess it could be some other signal from the phone causing interference, but the pattern seems to suggest it is the RF from the phone (which I believe will either be on the order of 800MHz or 2GHz).
I imagine I can't be the first person to experience this problem - any advice for a new ham? I'm really just not sure where to start trying to filter this signal - I've looked through catalogs but come up empty on any kind of ferrite core that meets my need.