On Thu, 9 Aug 2007, Andrew Rich wrote: > I note that the GPS15H does -5 to +5 on the data port unlike my GPS 18 > which does 0 to +5 volts swing This is known as pseudo-RS232; are the levels inverted? -- Dave _______________________________________________ Ozaprs mailing list Ozaprs at aprs.net.au http://aprs.net.au/mailman/listinfo/ozaprs