Pilot reported routinely losing communications with the NCT sector south of the KLIDE intersection in flight. After regaining contact; a conversation with the Controller revealed this is a known problem in the area.

Narrative

This has happened to me before. NorCal has a transmitter that doesn't reach lower-altitude aircraft on the instrument procedures into SJC from the south (RNAV 30L; ILS 30L). I believe it's 12x.675 or 12x.475. In any case; it's the sector prior to 120.1 to which you are switched about 10 miles prior to KLIDE. On this IFR flight; I was on a clearance and given vectors for sequencing over the Gustine area when the transmissions stopped reaching me. As I've seen this before; I proactively changed to 120.1 and was able to re-establish communications. Note; I had 121.5 monitored on my second radio and no attempt was made to reach me that way to effectuate the handoff to 120.1. Given that the weather was severe clear; I and others were in no significant danger. A controller explained to me once that the transmitter with the issue is located at El Nido (HYP). I suggest that the controller working the pre-120.1 sector be aware of the potential loss of transmission and should let pilots of smaller aircraft know that by KLIDE; they should be on 120.1 and to expect that in xxx minutes. Obviously this is not an issue for the airline/jet traffic coming in; but I've experienced this a couple times now.