Use of External Bluetooth Antenna Up2Stream

I’ve got a Up2Stream V3 Pro and mount it inside a metal housing (old CD Player). Since I expect the case to shield the bluetooth signal pretty well I, I’ve added SMA connectors for Wifi and Bluetooth. Wifi relies on a external Antenna anyway, so I see no Problem here.

Question is: If using a external Anenna do I need to disconnect the on board PCB Antenna through removing one of the 0 Ohm Resisotrs (see attached picture) to get the impedance right?


Hi Tobi,
I have done similar to you and never had any issues.
I cannot see that changing from the supplied stick-on antennas to external antennas would change the impedance?
From my experience, they work fine.

Hi Steve,
I don’t mean the wifi, but the Bluetooth Antenna. For the Bluetooth there is a printed antenna on the board (you can see it on the second picture) and if you now plug in an external antenna in addition they work parallel an half the impedance seen by the transceiver. From what I’ve read there are chips that can account for that, but not all of them. And my knowledge of hf stuff is very limited :sweat_smile:
I might just give it a try and let u know of the results

I reiterate, the IPEX/SMA cables and external antennae that I have used work perfectly fine.
You would need some specialised equipment to actually measure the antenna impedance.
You could remove the R0 resistor or cut the pc board track if you think it’s going to make a difference for you.
Happy DIY-ing!