Dump1090-Mutability: Message rate descending with E4000


#1

Hi there,

this is my first post on the forum, so please be patient … :wink:
I’m running the latest dump1090-mutability (github.com/mutability/dump1090/ … 2b4a876dd5) on a raspi 1, model b+.
As RTL-dongle I’m using Salcar DVB-T Stick which has a Raphael tuner (RTL2832U+R820T). All is working nice and stable so far.
However, I’m owning a Terratec Cinergy T Stick RC (Rev.3) with an Elonics 4000 tuner. As this one has a wider frequency range, I’ve tried to use it together with the dump1090. But what I’m experiencing is that the message rate descends from a litte over 300 msg/s down to 3 msg/s within a minute. The message rate from the salcar is stable around 200 msg/s, depending on the air traffic.
Now to my question: Has somebody similiar experience with the E4000 tuner and an idea why the message rate descends ?
My first idea was to play with the gain (from max to 10), but beyond 29 there was nearly zero message rate.
Best regards,

JD.


#2

The E4000 tuner has a gap where it can’t receive between approx 1100MHz and 1250MHz (it varies from unit to unit).
This is unfortunately right by the 1090MHz that dump1090 needs, so some E4000s just can’t hear 1090MHz.


#3

Hey,

thanks for the quick reply, seems like I just oversaw that … :frowning:
What stick would you recommend to work best ?
Greets,

JD.


#4

FAs own Dongle is the best value for money. I get nearly as good results as radarcape.
The larger Nooelec models also work well, but need the built in amp to compete with the FA dongle.
If you use an external/masthead amp then you don’t need an amp in the dongle. RTL-SDR are OK for this setup.


#5

Okay, thanks again for your tips.
I will check the fa dongle a little nearer.
Greets,

JD.