Cube Orange ADS-B sensitivity

We placed the ADS-B antenna in the best position for
a fixed wing drone, but the Cube Orange ADS-B sensitivity is really poor, compared with Ping-Rx external module.

As far as I know, the ADS-B carrier board uses exactly the same hardware as the external PingRX. How did you install your antenna and how are you measuring sensitivity?

Hi Rick,
the integration of ADSB Receiver in Cube has been a big effort and is a great achievement.
Starting from initial tests, we immediately realized that the Cube Orange ADSB range was not performing as the external Ping Rx receivers could.
Just to contribute to get better systems, we compared external Ping RX receivers (we have a couple of them connected to Cube Black) with the integrated ADSB receiver in Cube Orange.
All Receivers are at the top of the drone, in clear line of sight.
Positioning of the Ping Rx external receivers is far from the Cube and in the highest possible position, whilst the Cube Orange must be placed as near as possible to the CG of the drone and therefore the position of the ADSB Antenna location is fixed.
All the systems that we tested have the same configuration: RFD868 telemetry, the same 433 Mhz RC radio receiver and the same 5.8 Ghz video trasmitters.
We made the Cube Orange ADSB and the Cube Black ADSB work at the same time and we saw in Mission Planner that the external ADSB Ping Rx receivers connected to Cube Black had a range no less than 30 (thirty) kilometers (i.e.: in Mission Planner planes as far at least 30 kilometers were shown), whilst the Orange Cube ADSB could hardly show planes farther than a 2-3 kilometers.
I understand that the chips in the Ping Rx external module and the ones in Cube Orange internal module are the same, but the antenna performance might be absolutely different.
The Ping Rx external module antenna seems to be a dipole, whilst the Cube Orange Antenna is a (very fragile) linear one. The positioning of the antenna in Cube Orange may affect performance: it is partly covered by the metal frame of the carrier board, and a sector may be obstructed by the Cube, and possibly the radionoise from the carrier board may affect the receiver performance.
I understand that re-engineering is a problem, but probably the best solution might be having a (UFL?) connector to an external antenna to be placed in the best position within the drone.
Kind Regards.
Claudio

This is the core of my question - have you tested its performance when placed in the same position as the external RX modules? I don’t doubt that the integrated module might be less sensitive, but we first need to make an equal comparison by making measurements when they are mounted in the same position.

The carrier board has a spot to install a U.Fl connector - it might be worth doing this and trying your own antennas.