PSN-L Email List Message

Subject: GPS Group Buy
From: "Larry Cochrane" cochrane@..............
Date: Sat, 4 Aug 2001 15:06:40 -0700


The GPS receivers and antennas arrived on Friday. For the people who already
paid I will send out the orders on Monday. If you placed an order and have
not sent in your payment, now would be a good time to do it.

Here's some info on the GPS timing system;

If you ordered the receiver without the interface board you will need to
power the receiver with 5 VDC. The current requirements is around 200 ma
with the antenna attached. Since the serial input/output is not standard
RS232 voltage levels you will need to use a chip like the MAX232 RS232
driver / receiver IC. If you are going to use it with SDR you will also need
to wire up the 1 PPS signal. You can either place it on pin 1 of the 9 pin
RS232 connector or run a digital line to the 37 pin IO connector.

If you ordered the unit with the interface all you will needed to do is
supply a DC voltage in the range of ~7 to 40 volts. The current requirements
with the antenna attached is ~185 ma at 8 VDC, 125 ma at 12 VDC and 100 ma
at 15 VDC. The power should be applied to the +pwr and -pwr solder holes. Do
not use the +- Bat inputs. Since the GPS receivers already have a battery
installed in them, these inputs should be left open. To connect the unit to
your PC use a standard serial cable. You do not need a null modem adapter or
cross-over cable.

In SDR set the "Set Time Using Comm Port" menu item to the port number and
set "GPS Mode" to Yes. After restarting SDR it may take a while for the unit
to first lock up to the GPS time.

I bought a few extra receivers and antennas so if you would like one send me
an email message.

-Larry Cochrane
Redwood City, PSN


Public Seismic Network Mailing List (PSN-L)

[ Top ] [ Back ] [ Home Page ]

Larry Cochrane <cochrane@..............>