Unique Broadband Systems GPR1100 GPS Disciplined 10MHz Oscillator UBS *PARTS* [For Parts]

*** FOR PARTS OR REPAIR *** • Tested • OCXO Oscillator • Quad 10MHz GPSDO • Quad 1PPS Outputs • Sine Wave 10MHz Output • Rear BNC Ports • 5V Antenna Voltage • Web Management Interface

Here's a used UBS GPR1100 GPS time receiver and frequency generator that's in good cosmetic condition. It is being offered for sale for parts or repair with no returns accepted as it only works partially. See screenshots below for my testing results. The unit has an internal 10 MHz OCXO oscillator which drives four sine wave outputs on BNC rear panel connectors. There are also four 1 PPS outputs.

In my testing, the iLotus GPS card achieved sync with GPS and showed correct position and time, however the date was 1024 weeks in the past, indicating a WNRO event on the card, which is common for cards of this age. Given that this is mainly a pulse/frequency generator I doubt that changing the GPS card is a high priority as the date information is only used by the RS-232 output which not ASCII coded.

I did not see any output on the RS-232(1) port (looking for 9600-8-N-1) which may be due to the output being suppressed due to lack of full 10MHz lock, or maybe a fault condition.

The front panel and web display suggests that the 10MHz oscillator is not being disciplied by the GPS system and I did notice that the OCXO can was cooler than I think is normal, so maybe the heater element has failed? The datasheet for the installed oscillator (VFOV405-RDECH-10.000MHZ) may be found at https://www.prostudioconnection.net/2609/VFOV405.pdf in case you are looking to source a replacement or substitute. I notice that the PCB has provision for a SMD 'square type' oscillator package also so you have other options for a replacement unit.

Normally there is output on the RS232(1) port every second. Note that this is CMMB not ASCII encoded so will not be useful unless you have a means of reading a CMMB timecode signal. So the potential absence of that signal may not be a great loss.

The antenna voltage is 5V so you can use almost any professional grade outdoor antenna (26dB gain or more recommended). The antenna connection is a F-Connector type. The antenna will need to be sited outdoors with a complete view of the sky. Operation behind a window or with an obstructed view of the sky will probably not be successful. The GPS module is a generic iLotus 12 Channel Motorola M12+ clone so it's probably easily replaced or upgraded if the need arises.

There's a basic web interface (see screenshots below) and the unit ships set to an IP address of 192.168.1.188 so it should be accessible from the most commonly-used subnet address range. DHCP is not supported. The log in is [blank]:admin. The IP address can be changed most easily via the web interface - maybe using direct connection via a cross over cable if your LAN uses an address range that's different from the current setting.

Parameters can also be changed via a serial port on the back panel. But this is a RS-485 type so it cannot be directly connected to a PC's RS-232 serial port - an adapter/converter will be needed to convert from 3-wire RS-232 communications to the 4-wire full duplex RS-485 standard. The rear panel RS-485 DB9 connector is wired to a proprietary pin-out (details in the manual) so you will probably need to custom wire a DB9 male connector in order to change the config via the console port (hence the recommendation that you use the web interface for greater simplicity). For this reason the RS-485 port has not been tested.

In my testing I entered the URLs of the config pages in the form http://192.168.1.188/cgi_ipradio?type=1XX where I changed the value of XX to access the different pages (see below). No printed manual is included but a copy may be downloaded from https://www.prostudioconnection.net/2112/UBS_GPR1100_Manual.pdf if required.

Note that I'm sharing the results of my testing to help you in your purchase decision, but I do not guarantee that you will get the same results or reach the same conclusions. Nor that I haven't missed some important point.

Description (Conformance NOT Guaranteed)

Based on a M12MT receiver module, the UBS GPS receiver is a compact, cost effective, GPS locked timing reference.

Designed for applications where 10MHz/1pps clock sources are required to synchronize multiple transmission devices, this module provides an accurate high quality signal set. Multiple outputs enable all base station/site equipment to share a single accurate and stable reference source.

Optionally, UBS GPS receivers provide TOD information via a serial RS232 port, compliant with CMMB standard requirements.

The GPR 1100 unit includes a GPS receiver, as well as a 10 MHz and 1pps distribution system. GPR1100 also includes a controller module, supporting WEB GUI and SNMP interfaces over an Ethernet connection.

Product Features