GPS Multiplexer design

Actually GPS is at ~1.5GHz. I'm not quite sure what the OP is trying to do, but you can get off-the-shelf cable TV splitters/combiners that are good to

Others have noted that cable TV splitters/combiners are available here in the US.

But I'm dubious about 2-in/1-out for GPS. Combining two GPS signals from antennas separated by more than the GPS resolution is a recipe for confusion.

Tim.

Sorry for the confusion.....I meant the rs232 nmea output signal

You want to multiplex the RF of the GPS at 2.5GHz or so ? You're aware that the GPS signal over cable looses quite a bit of amplitude ?

Rene

These TV components are not known to have a high isolation, their focus is to be cheap.

Rene

You need to give more information unless you want to get a bunch of useless answers.

How do you want to control the selection between the two GPS's? Do you want to magically do it by way of the RS-232 port? Could it be a pushbutton? A jumper?

Or maybe you are thinking that you can get all the messages from both GPS's? This would probably require more than a simple mux.

Does this "mux" need to be powered from the RS-232 line, or could it be battery powered, or does it have to be line powered, maybe? If line powered, what Voltage and what frequency?

--Mac

Lotsa places make NMEA multiplexers with various features:

Sometimes they're used to put both a main and backup GPS on the same serial stream, but usually they do 1 GPS receiver, 1 wind sensor, 1 compass, etc (all of which speak NMEA).

Tim.

A mux made from two and an an inverter is sufficient. Or perhaps a 74HCT138 or a 74HCT155 or such.

Rene

mniti sez "Sorry for the confusion.....I meant the rs232 nmea output signal"

The most straightforeward way to do this is by using a USB-to-RS232 hub. I've used this when I had two GPS receivers being used for a form of differential GPS. The other way would be a gizmo from B&B Electronics