[time-nuts] Galvanic decoupling of GPS antenna

[Christian Vogel]

Hi Yuri,

> I'm trying to put gps (for a coarse timing sync and RTC
> auto-setting) to a small controller that must be completely
> galvanically decoupled from outside world. Antenna power must be
> supplied from separate power source (ground potential of isolated part
> of circuit can slowly float up to +/- 250 volts referenced to ground
> of antenna power supply).

I don't see any need for isolation in the signal chain as long as your
antenna and cable are properly insulated. I have a fully sealed antenna
here on a Thunderbolt and nothing -with exception of the BNC connector
at the cable end- exposes the system ground. So I could easily float
the TBolt and connected PC at +250V without anyone "outside" noticing.

	Chris