Table of Contents
The following contains interesting notes about each daughterboard. Eventually, this page will be expanded to list out the full properties of each board as well.
The Basic RX and LFRX boards have 4 subdevices:
The boards have no tunable elements or programmable gains. Though the magic of aliasing, you can down-convert signals greater than the Nyquist rate of the ADC.
The Basic TX and LFTX boards have 4 subdevices:
The boards have no tunable elements or programmable gains. Though the magic of aliasing, you can up-convert signals greater than the Nyquist rate of the DAC.
The DBSRX board has 1 quadrature subdevice.
Receive Antennas: J3
The board has no user selectable antenna setting
Bandwidth (Hz): 8M-66M
Transmit Antennas: TX/RX
Receive Antennas: TX/RX or RX2
The user may set the receive antenna to be TX/RX or RX2. However, when using an RFX board in full-duplex mode, the receive antenna will always be set to RX2, regardless of the settings.
Receive Gains: PGA0, Range: 0-70dB (except RFX400 range is 0-45dB)
The XCVR2450 has a non-contiguous tuning range consisting of a high band (4.9-6.0GHz) and a low band (2.4-2.5GHz).
Transmit Antennas: J1 or J2
Receive Antennas: J1 or J2
The XCVR2450 uses a common LO for both receive and transmit. Even though the API allows the RX and TX LOs to be individually set, a change of one LO setting will be reflected in the other LO setting.
The XCVR2450 does not support full-duplex mode, attempting to operate in full-duplex will result in transmit-only operation.
Transmit Antennas: TX/RX
Receive Antennas: TX/RX or RX2
The user may set the receive antenna to be TX/RX or RX2. However, when using an WBX board in full-duplex mode, the receive antenna will always be set to RX2, regardless of the settings.
Transmit Gains: PGA0, Range: 0-25dB
Receive Gains: PGA0, Range: 0-31.5dB
Receive Antennas: RX
Bandwidth: 6MHz
Sometimes, daughterboards will require modification to work on certain frequencies or to work with certain hardware. Modification usually involves moving/removing a SMT component and burning a new daughterboard id into the eeprom.
Due to different clocking capabilities, the DBSRX will require modifications to operate on a non-USRP1 motherboard. On a USRP1 motherboard, a divided clock is provided from an FPGA pin because the standard daughterboard clock lines cannot provided a divided clock. However, on other USRP motherboards, the divided clock is provided over the standard daughterboard clock lines.
Step 1: Move the clock configuration resistor
Remove R193 (which is 10 ohms, 0603 size) and put it on R194, which is empty. This is made somewhat more complicated by the fact that the silkscreen is not clear in that area. R193 is on the back, immediately below the large beige connector, J2. R194 is just below, and to the left of R193. The silkscreen for R193 is ok, but for R194, it is upside down, and partially cut off. If you lose R193, you can use anything from 0 to 10 ohms there.
Step 2: Burn a new daughterboard id into the EEPROM
With the daughterboard plugged-in, run the following commands:
cd <prefix>/share/uhd/utils ./usrp_burn_db_eeprom --id=0x000d --unit=RX --args=<args> --slot=<slot>
Older RFX boards require modifications to use the motherboard oscillator. If this is the case, UHD will print a warning about the modification. Please follow the modification procedures below:
Step 1: Disable the daughterboard clocks
Move R64 to R84, Move R142 to R153
Step 2: Connect the motherboard blocks
Move R35 to R36, Move R117 to R115 These are all 0-ohm, so if you lose one, just short across the appropriate pads
Step 3: Burn the appropriate daughterboard id into the EEPROM
With the daughterboard plugged-in, run the following commands:
cd <prefix>/share/uhd/utils ./usrp_burn_db_eeprom --id=<rx_id> --unit=RX --args=<args> --slot=<slot> ./usrp_burn_db_eeprom --id=<tx_id> --unit=TX --args=<args> --slot=<slot>