Sometimes, you simply need Bluetooth HIGH Energy📡
@stacksmashing nooo, not the 5G^wBluetooth waves 
@stacksmashing Would be appropriate if the transceiver was a Silabs Mighty Gecko

@stacksmashing How much gain are you able/have calculated to get from this PCB-Yagi design?

It would also be interesting to know how much the two screws influence it.

@DF3LX I haven't measured it yet - but the directional effect is very very noticable. The antenna is just a random cheap one.

I was frustrated with all nRF-based BLE sniffers that I could find only having not-so-great chip-antennas.

Even with a 2.4GHz stub-antenna this one performs sooo much better

@stacksmashing BTLE OBject EXchange:  

BTHE OBliterate EXplode: 

@stacksmashing #alt4you image description: hextree.io USB ble sniffer PCB that's about the size of a USB stick, connected on one end to a large flat PCB antenna. the antenna has a 3d printed grip attached to one end, making the whole contraption look like a pistol
@stacksmashing I bet it also vaccinates you while doing an active scan! ;)
@stacksmashing Would have expected a https://www.nordicsemi.com/Products/nRF21540 on there for maximum RF pew :)
@timonsku I'm just glad my "transmission line" works at all :D