Ettus Research GPSDO Quick Start Manual

Installing the Ettus Research™ GPSDO Kit for USRP™ N200 Series & E100 Series

Kit Contents:


1 GPSDO module

1 Power cable (2 wires)

2 RS-232 cable, 22cm (3 wires)

1 RS-232 cable, 8cm (3 wires)

2 SMB right angle to SMA right angle
cables

1 MMCX to SMA-Bulkhead cable

2 Screws

GPSDO Connectors:

A. RS-232 (Pins: 1. TX, 2. GND, 3. RX)
B. 1 PPS
C. 10 MHz Ref Clock
D. Power (Pins: 1. GND, 2. GND, 3. +6V)
E. GPS Antenna

Instructions:

1. Remove the daughterboard from the USRP motherboard if present.
2. USRP N2xx Only: Move J510 jumper on the motherboard from 1-2 to 2-3 in order to switch from
external 10 MHz Ref Clock to GPSDO's 10 MHz Ref Clock
3. Screw the GPSDO module in place with the screws provided. The screws are treated to avoid
loosening with vibration.
4. Connect the GPSDO power cable to J509 (N200) / J101 (E1xx) on the motherboard, and then to
connector D on the GPSDO module
5. Connect an SMB to SMA cable between connectors B and J506 (N200 -PPS2) / J13 (E100 – PPS)
6. Connect an SMB to SMA cable between connectors C and J507 (CLK REF2) / J10 (E100 – REF IN)
7. The kit includes three non interchangeable serial cables to be used with different USRP revisions
and/or models. The 8cm long cable is for N200 series revision 4 or above and the E100 series
revision 5 or above. The 22cm long cable with the black wire connected to the center pin on
both ends of the cable is for the USRP N200 revisions 2 & 3. The 22cm long cable with a colored
dot on the connector that has ground (black wire) on pin 1 is for the USRP E100 revision 4.
8. USRP N2xx Rev 2 & 3: Locate J312 on the front of the motherboard and connect either end of
the appropriate 22cm long serial cable to it. If J312 on your USRP isn't a keyed connector, please
ensure to connect pin1 (TX) of connector A to the RX pin on J312.
9. USRP N2xx Rev 4 or higher: Locate J312 on the back of the motherboard near the GPSDO power
connector and connect either end of the 8cm long cable to it.
Ettus Research
4600 Patrick Henry Drive
Santa Clara, CA 95054
USA
P: +1-408-610-6399 – F: +1-866-807-9801 – ettus.com
Important: Please make all
connections with the
USRP powered OFF.
Rev. 2.1 – 5 May 2014