Post-production testing

Basic checks to perform after production to make sure there are no critical issues with manufacturing.

Required instruments:

1. Laboratory Power Supply Unit (PSU) 3-15V/0-2A with DC current indication or external ammeter.
2. Voltmeter or multimeter with good accuracy.
3. Spectrum analyzer, at least as good as Signal Hound.
4. PC with 1GbE port, configured with IP
5. 1GbE capable cable, plugged into the PC port described above.
6. RF cables, adapters, attenuators etc.


You should download and build the Fairwaves version of UHD.

Then follow normal UHD build instructions. You only need to build 'host' part of UHD.


1. Critical issues

Check that all critical issues are fixed or worked around for the unit under the test.

2. Short circuit

Adjust PSU current limit to 1-1.5A, set voltage to 3-4V and double check polarity. Apply power to UmTRX and check UmTRX current consumption with the PSU:

  • If the current consumption of UmTRX is limited by the PSU, check the power polarity. If the polarity is correct, mark this UmTRX unit as defective with the "over-current" label.
  • If the current consumption is below the limit, slowly increase PSU output voltage to 12V. Current consumption should be less then 0.5A at 12V - probably around 0.3A (without Ethernet cable connected and without firmware loaded).

3. DC-DC converters

Test voltages of all the following test points:
C140 2.5V
C138 1.2V
C141 3.3V
C131 6V
U18 5V
U28 3.3V
U29-1, U29-2 3.3V
U30-1, U30-2 2.5V
U31-1, U31-2,brU32-1, U32-2 1.8V
Collector Q3br near GBEth 1.0V

4. Clock source

Check that both switches of the S3 dip-switch are turned down (position "master"). Check that LED-I lights constantly (indicates that clock is OK) and LED-G lights constantly (indicates that GPS is powered on).

5. Ethernet PHY

Plug in an Ethernet cable, connected to a 1GbE network.

  • Current draw should increase by about 100-150mA.
  • LED6 and the right LED on the Ethernet connector should light constantly, LED5 and the left LED on the Ethernet connector might blink.

6. FPGA firmware

1. Switch off power.
2. Connect JTAG adapter.
3. Switch on power back.
4. Load firmware.

Firmware images:

[[span(style=color: #FF0000, Describe LED status and debug port output.)]]

7. GPS sync

Connect GPS antenna and wait for ~1 min for LED G to start blinking - this means that GPS sync is acquired.

8. LEDs status

Check all LED's in according to functionality as described in [FeaturesAndTechnicalSpecification].

9. LMS init

[[span(style=color: #FF0000, Describe for both LMS chips.)]]

Connect the spectrum analyzer (SA) to the TX1 port and set the SA and TX to the same frequency, e.g. 960MHz. Find the TxLO leakage level.

To check LMS control lines adjust its configuration.

Usual contents of .bat file to init basic functions:

set lms=%C:\Python32\UmTRX\ --umtrx-addr --lms 1%
%LMS% --lms-init
%LMS% --lms-tx-enable 1
%LMS% --lms-rx-enable 1
%LMS% --lms-set-tx-vga1-gain -10
%LMS%  --pll-ref-clock 26e6 --lpf-bandwidth-code 0x0f --lms-auto-calibration
%LMS% --lms-tx-pll-tune 960000000
%LMS% --lms-set-tx-pa 2
%LMS% --lms-set-tx-vga2-gain 20
%LMS%  --lms-rx-pll-tune 915000000
%LMS% --lms-set-rx-vga2-gain 9
%LMS% --lms-set-rx-lna 3

10. Modulated Tx

Generate a modulated signal and check power consumption by functionality as described in PowerConsumption.

Exercise case as the modulated signal of UmTRX will be much higher than TxLO leakage and could damage your SA!

To get ideal GMSK modulation might be used the next example:

tx_samples_from_file.exe --rate 1083333 --freq 9478e5 --file gmsk.cfile --loop

To make measurements of phase error etc, better to run OpenBTS after LMS6002DCalibration.

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