Antenna >> Generic DVB-T (No Filter, no LNA)
Gain = 49.6
Antenna >> RTL-SDR Triple Filter LNA (Old Model) >> Generic DVB-T
Gain = 49.6
Thanks @abcd567
Curious to know the reason/s for the change. Availability? Cost?
Either would suffice, if neither, bad move all around.
Comparing the two datasheets, the new (TA1090EC) filter claims a lower insertion loss (2.3 vs 3.0dB), however it’s out of band performance is significantly poorer.
The bandwidth specified for each filter appears to be the bandwidth for which the amplitude ripple is within spec.
It’s common for (filter) bandwidth to be specified at the 3dB points. Using this definition, I make the TA1090EC about 40MHz bandwidth.
The SF9175 is a bit harder to read, but looks to be about 20MHz
I just got mine. This is the PCB which side is the output taking the 5v? I will do a scan tonight comparing the flightaware blue to the rtl dongle filter combo.
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So I just did a scan.
FA Pro Stick Plus
And then the RTL-SDR dongle + Triple Filter
But the result is more than funky, the dump 1090 is definitely picking up more aeroplanes so surely that is not the case…
I’m trying the same scan again we will see what happens, unless you have another suggestion @abcd567 @wiedehopf (Second scan gave the same result. Another user @Flipkaan had a similar scan but I can’t see a resolution)
Did you adjust the gain after adding the filter?
The scan sets 29.7db gain other wise I have not adjusted it.
Looks like the LNA has no power in that scan.
ok so should i modify the commands? adding ~/rtl_biast/rtl_biast -b 1 so I would run the following commands.
sudo systemctl stop dump1090-fa
~/rtl_biast/rtl_biast -b 1
sudo rtl_power -f 800M:1200M:100k -i 30 -c 50% -e 30m -g 30 -F 9 >scan.csv
Might be that rtl_power that you use can control the bias tee itself, check rtl_power -h
(it might switch it off if not specified on the cmd line)
[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]
Looks like -T ? I add that with a value of 1 or 0 so it would be
sudo rtl_power -f 800M:1200M:100k -i 30 -c 50% -e 30m -g 30 -F 9 -T x >scan.csv
Doesn’t look like it wants a parameter, just the option.
Why haven’t you just tried yet? 
Try scan by “Spektrum” . It is very fast, each sweep takes only about 1 minute so leting her run for 5 minutes is enough. Another advantage is that the sweep is very wide, from 24 Mhz to 1200 Mhz, hence not only covers Cell/Mobile signals, but also covers signals FM VHF TV, UHF TV, VHF Amature, Police, Fire, Taxi etc etc.
Antenna >> Generic DVB-T (No Filter, no LNA)
Gain = 49.6
CLICK ON IMAGE TO SEE LARGER SIZE
Antenna >> RTL-SDR Triple Filter LNA >> Generic DVB-T
Gain = 49.6
CLICK ON IMAGE TO SEE LARGER SIZE
He needs to enable his bias-t. (RTL-SDR radio)
The rtl_biast answer he provided himself (depending on the age of the software installed) should be the proper method, not sure it was tried.
Oh yeah i misread that and assumed that’s the commands he used.
Anyhow if rtl_power has the -T option, it might be necessary to use that otherwise it might even turn off the biastee if you don’t specify the option.
Thanks for the replies @Nitr0 @wiedehopf @abcd567 I will try adding -T and report back
It certainly does (now), but I don’t think it did on buster repo 0.6-1, so it would more than likely need to be built from source to apply. Since we’re not sure what has been installed and how and on what, it’s impossible to provide a proper answer. My first reply was in response to using Spektrum and that it won’t do a bit of good in this instance unless there is an external bias-t inline.
To build from source (assuming proper prereq’s are already installed from the piaware/dump1090-fa installation):
## BUILD & INSTALL RTL-SDR FROM SOURCE ##
git clone https://github.com/osmocom/rtl-sdr.git
cd rtl-sdr
mkdir build && cd $_
CFLAGS="-march=native" cmake ../ -DINSTALL_UDEV_RULES=ON -DDETACH_KERNEL_DRIVER=ON
make -j4
sudo make install
sudo cp ../rtl-sdr.rules /etc/udev/rules.d/
sudo ldconfig
cd
EDIT: The -T option was added June 12,2017, so it should be in the repo version. Not near my machines to check. Guess we’ll know soon enough
Wont the command rtl_power --help list all the options? This will confirm if his install has / does not have T option.
or
rtl_power -h
indeed.