Writing to ask about an odd thing I have observed. I have a 4500 EFIS. It is hooked to a 430W and I have a 696 in the panel as a stand alone GPS back up. The 4500 clearly upsets the 696. When I turn on the 696 by itself it locks quickly and works great. When I turn on the 4500 all GPS reception bars drop dramatically, some disappear and the 696 is not able to reliably keep a signal. If the EFIS is on when the 696 is first turned on it won't even get a lock. I have carefully checked each set of avionics and nothing interferes with anything else but this one. When I use a remote antenna on the 696 problem is mostly unchanged but if I move the remote antenna 10 feet away the 696 reception appears pretty good, but if I turn off the EFIS all signals still get noticeably better. Have you seen this before? Perhaps a problem with the 696?