OGN Noise

[tmmtaha75]

1. Stratux version: Latest European version

2. Stratux config:

   SDR

   • single
   • [ x] dual

   GPS

   • [x ] yes
   • no
     type:

   AHRS

   • [ x] yes
   • no

   power source:

   usb cable:

3. EFB app and version: (e.g., WingX Pro7 8.6.2)

   EFB platform: (e.g., iOS 9.2)

   EFB hardware: (e.g., iPad Mini 2)

4. Description of your issue:
   I bought 868 MHz antenna from the following link>
   https://www.amazon.de/-/en/gp/aw/d/B09522Y6H9?psc=1&ref=ppx_pop_mob_b_asin_title
   and I'm getting OGN Noise@Gain 50: 22.8 dB, range loss: 13.80x (red)
   What am I doing wrong?
   If possible, enable "Replay Logs", reproduce the problem, and provide a copy of the logs in http://192.168.10.1/logs/stratux/ and http://192.168.10.1/logs/stratux.log.

[b3nn0]

Sadly, combating noise is non-trivial and often feels random..
Some things you can try:

• Make sure you don't test close to noise emitting devices, such as your PC. Put your Stratux outside, or even better test in the real world, i.e. in flight
• play with antenna positioning - the further away from the PI's CPU, the better
• You might want to try putting a ferrite core around your antenna or power cable
• Try a different power source, some introduce more noise than others

[tmmtaha75]

So you don't think it's the antenna itself? It's pretty short compared to the 1090 one. Do you have a recommendation on where to buy a long 868 MHz antenna in Europe?

[VirusPilot]

As Adrian said implicitly, it is likely not the antenna itself. In fact on it's face this antenna seems to be quite good, although I would also prefer a λ/2 antenna (~17cm). A good alternative are T dipole antennas like this:https://shop.prodrone.pl/en_US/p/ProFlex_Long-Dipole-868Mhz-915MHz/264?currency=EUR

[tmmtaha75]

Thanks a lot! I suspected the antenna because I don't get this much noise with the 978 MHz one. Thanks again for the help.

[b3nn0]

Well, it's not that simple, sadly. While it can be partly caused by the antenna, it doesn't have to be.
E.g. if there really is a lot of noise on the 868Mhz band, then of course, the 978 antenna will not pick it up as good as the 868Mhz one. So basically the only thing you observe is, that your antenna is picking up a lot of noise, but you don't know what the reason is. It is likely that this noise is simply there, from whatever sources.
Trying different antennas is - of course - never a bad idea though.

[VirusPilot]

FYI, the following antenna is highly recommended, although a bit difficult to purchase: https://www.taoglas.com/product/ti-85-2113-2dbi-868mhz-terminal-mount-dipole-antenna/