# RFID nano works without external antenna, but the external antenna doens't work

**URL:** <https://community.sparkfun.com/t/rfid-nano-works-without-external-antenna-but-the-external-antenna-doenst-work/38371>\
**Category:** NFC & RFID\
**Created:** [December 4, 2019, 4:14pm UTC](https://community.sparkfun.com/t/rfid-nano-works-without-external-antenna-but-the-external-antenna-doenst-work/38371 "2019-12-04T16:14:09Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sriharshapk](https://avatars.discourse-cdn.com/v4/letter/s/a6a055/32.png) [@sriharshapk](https://community.sparkfun.com/u/sriharshapk)\
**Post date:** [December 4, 2019, 4:14pm UTC](https://community.sparkfun.com/t/rfid-nano-works-without-external-antenna-but-the-external-antenna-doenst-work/38371/1 "2019-12-04T16:14:09Z")

</div>

When I power up the RFID reader nano (900MHZ) and use RFID tags to check if they are being read, it works. But when I connect the antenna (SparkFun UHF RFID Antenna), it doesn’t detect the tags. I checked the documentation, but I don’t see any code changes needed to connect the external antenna. Please anybody point me in the right direction to debug this issue. All devices are very new and I don’t see any flaws with them.

---

<div class="post-metadata">

**Author:** ![TS-Chris](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/ts-chris/32/6057_2.png) [@TS-Chris](https://community.sparkfun.com/u/TS-Chris)\
**Post date:** [December 4, 2019, 4:36pm UTC](https://community.sparkfun.com/t/rfid-nano-works-without-external-antenna-but-the-external-antenna-doenst-work/38371/2 "2019-12-04T16:36:27Z")

</div>

Have you changed the jumpers required to select the external antenna?