Hi! I’ve built my configuration based on the SparkFun Simultaneous RFID Reader - M6E Nano hardware hookup on the SparkFun website and have attached photos below. I’m using the example constant read script provided by SparkFun in the Arduino IDE. I’m using the SRTR as a shield on an Arduino Uno, as well as a SparkFun 900MHz antenna and USB cable connecting the Arduino board to my laptop. The code runs however the SparkFun UHF tags are not read. I’ve swapped the uFl cable and USB cable and still no change. What can/should I do? Thank you so much for your time in advance 
Couple of things to check :
Is the sketch able to find and connect with the M6E board ?
else check the UART switch in SW UART and the sketch is using SoftwareSerial on D2 and D3 ?
Make sure the board does NOT short-circuit with the USB adaptor
Looking a the IMG-0090.jpg, you have an external antenna connected, but the solder blob still connects with the onboard antenna.
Do you use low reading power in the sketch ?
What happens if you put the UHF tag right on top of the (on-board) antenna?
Hi Paul,
Thank you so much for your reply - I’ve managed to get the board to read tags successfully but within a very small range. ie. 1 inch.
I’ve added a 6vDC power supply (no 5vDC available at the moment).
I also adjusted the reading power to 27 dBm.
Only the on-board antenna functions; regarding what you said about soldering and the external antenna connection, what should I do?
Best wishes,
Sofia
Make sure to apply a strong power supply directly to the M6E. Connecting to the UNO will not help as it will support only 1A. Check this forum for many other posts around this Topic.
For the external antenna see : https://learn.sparkfun.com/tutorials/si … al-antenna