I love modesdeco2 -- I am using an Odroid XU4 with the Airspy unit and a 1090 preamp/bandpass filter. I constructed a 7-segment CoCo antenna form RG402 and it is tuned spot on (SWR 1.5 at exactly 1090). With the antenna top at 12 feet and shaded by trees and houses, I am receiving planes out to 170 nm. I am sure range will improve when I mount it higher.
Problem: I want to feed the preamp up the coax from the AIrspy Bias T option. Airspy's toolset supports it, but it is turned off when I run modesdeco2. Please consider adding an option to set the "bias T" enable when starting the Airspy unit. The specific Airspy option is:
[-b biast]: Set Bias Tee, 1=enabled, 0=disabled(default)
Hello tjkaminski,
Sorry for the late reply. I will try to add support for this option as soon as get back from vacation.
Regards,
sergsero
Thanks, it will be appreciated. Have fun on you vacation.
Hello,
New version of modesdeco2 with option
--airspy-rfbias (The Bias-Tee option: 4.5v @ 50mA) was tested. In the near future I will try to upload it.
sergsero@ac168:~/sdr/modesdeco/build/modesdeco$ ./modesdeco --airspy --verbose --airspy-rfbias
2015-10-03 20:30:28.850 INFO ModeSDeco2 v.20151003
2015-10-03 20:30:28.852 INFO Board ID Number: 0 (AIRSPY)
2015-10-03 20:30:28.852 INFO Firmware Version: AirSpy NOS v1.0.0-rc4-0-g23d1436 2015-03-22
2015-10-03 20:30:28.852 INFO Part ID Number: 0x6906002B 0x00000030
2015-10-03 20:30:28.852 INFO Serial Number: 0x16C463C82
2015-10-03 20:30:28.853 INFO Supported sample rates: 10.0 2.5
2015-10-03 20:30:28.853 INFO Oversampling Factor: 5
2015-10-03 20:30:28.853 INFO RF Bias: On
2015-10-03 20:30:28.853 INFO LNA Gain: 15
2015-10-03 20:30:28.854 INFO Mixer Gain: 15
2015-10-03 20:30:28.854 INFO IF Gain: 8
(https://dl.dropboxusercontent.com/u/79709204/Pictures/20151003/modesdeco2_airspy_biastee.jpg)
QuoteThe Bias-Tee option allows powering such a preamplifier directly from Airspy by injecting DC at 4.5v. Of course, such a preamp should have its own biasing system to extract the DC and inject the amplified RF signals. The current budget is limited to 50mA, so that's enough to run most of the modern MMICs.
Regards,
sergsero
The version 20151005 for test new option --airspy-rfbias for Airspy receiver.
+ added Bias-Tee option --airspy-rfbias that allows powering a LNA directly from Airspy by injecting DC at 4.5v.
A preamplifier should have its own biasing system to extract the DC and inject the amplified RF signals. The current budget of Airspy is limited to 50mA.
Please note!
If you have used the option --airspy-rfbias, the supply voltage on the sma connector will be remain until you disconnect the receiver from the USB port or to re-run the program without this option.
Windows
modesdeco2_windows_20151005.zip https://drive.google.com/open?id=0B7NYXizl0U6iOWNNajU4VkNfZDA (https://drive.google.com/open?id=0B7NYXizl0U6iOWNNajU4VkNfZDA)
Ubuntu 14.04
modesdeco2_i386_20151005.tgz https://drive.google.com/open?id=0B7NYXizl0U6iLVdBU1ZpamxxY0k (https://drive.google.com/open?id=0B7NYXizl0U6iLVdBU1ZpamxxY0k)
modesdeco2_x86_64_20151005.tgz https://drive.google.com/open?id=0B7NYXizl0U6iekJ6WFZwb0lVVTg (https://drive.google.com/open?id=0B7NYXizl0U6iekJ6WFZwb0lVVTg)
If you are connected the Airspy in Ubuntu for the first time, it is possible that you need to add some udev rules to make the receiver available for the non-root users: http://xdeco.org/?p=216 (http://xdeco.org/?p=216)
Regards,
sergsero