It's failed, again šŸ™

FlightAware ADS-B Flight Tracking
1

So after a couple of days solid performance I checked just a while ago and find my airspy/pi/piaware 3.7.1 system is down again. Itā€™s the same failure that I thought I had caused by making a bad setting however this time nothing has been touched. I rebooted, and waited but l I have the same problem. Below is what i get for a piaware-status and a sudo journalctl -u piaware | grep -v ā€˜reported location|ā€“lat|feeder IDā€™

Thanks for any ideas
Martin

1090 Receiver: warning: Connected to Mode S receiver, but no recent data seen.

pi@piaware:~ $ piaware-status
PiAware master process (piaware) is running with pid 1487.
PiAware ADS-B client (faup1090) is running with pid 1534.
PiAware ADS-B UAT client (faup978) is not running.
PiAware mlat client (fa-mlat-client) is running with pid 1543.
Local ADS-B receiver (beast-splitter) is running with pid 388.

beast-splitter (pid 388) is listening for connections on port 30005.
no program appears to be listening for connections on port 30978.
faup1090 is connected to the ADS-B receiver.
faup978 is NOT connected to the ADS-B UAT receiver.
piaware is connected to FlightAware.

got ā€˜couldnā€™t open socket: connection refusedā€™
the ADS-B data program at localhost/29999 is NOT producing data on localhost:29999.
got ā€˜couldnā€™t open socket: connection refusedā€™

pi@piaware:~ $ sudo journalctl -u piaware | grep -v ā€˜reported location|ā€“lat|feeder IDā€™
ā€“ Logs begin at Tue 2019-08-27 14:54:15 +07, end at Tue 2019-08-27 15:25:38 +07. ā€“
Aug 27 14:54:25 piaware systemd[1]: Started FlightAware ADS-B uploader.
Aug 27 14:54:28 piaware piaware[399]: creating pidfile /run/piaware/piaware.pid
Aug 27 14:54:28 piaware piaware[399]: ****************************************************
Aug 27 14:54:28 piaware piaware[399]: piaware version 3.7.1 is running, process ID 399
Aug 27 14:54:28 piaware piaware[399]: your system info is: Linux piaware 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux
Aug 27 14:54:29 piaware piaware[399]: Connecting to FlightAware adept server at piaware.flightaware.com/1200
Aug 27 14:54:29 piaware piaware[399]: Connection to adept server at piaware.flightaware.com/1200 failed: couldnā€™t open socket: Temporary failure in name resolution
Aug 27 14:54:29 piaware piaware[399]: reconnecting in 66 secondsā€¦
Aug 27 14:54:32 piaware sudo[628]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:54:32 piaware sudo[628]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:54:32 piaware sudo[628]: pam_unix(sudo:session): session closed for user root
Aug 27 14:54:32 piaware piaware[399]: ADS-B data program ā€˜beast-splitterā€™ is listening on port 30005, so far so good
Aug 27 14:54:32 piaware piaware[399]: Started faup1090 (pid 636) to connect to beast-splitter
Aug 27 14:54:32 piaware piaware[399]: UAT support disabled by local configuration setting: uat-receiver-type
Aug 27 14:55:02 piaware piaware[399]: 0 msgs recvā€™d from beast-splitter; 0 msgs sent to FlightAware
Aug 27 14:55:35 piaware piaware[399]: Connecting to FlightAware adept server at piaware.flightaware.com/1200
Aug 27 14:55:35 piaware piaware[399]: Connection with adept server at piaware.flightaware.com/1200 established
Aug 27 14:55:36 piaware piaware[399]: TLS handshake with adept server at piaware.flightaware.com/1200 completed
Aug 27 14:55:36 piaware piaware[399]: FlightAware server certificate validated
Aug 27 14:55:36 piaware piaware[399]: encrypted session established with FlightAware
Aug 27 14:55:37 piaware sudo[959]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:55:37 piaware sudo[959]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:55:37 piaware sudo[959]: pam_unix(sudo:session): session closed for user root
Aug 27 14:55:37 piaware piaware[399]: logged in to FlightAware as user hs0zed
Aug 27 14:55:37 piaware piaware[399]: site statistics URL: https://flightaware.com/adsb/stats/user/hs0zed#stats-109298
Aug 27 14:55:38 piaware piaware[399]: multilateration data requested
Aug 27 14:55:38 piaware sudo[985]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:55:38 piaware sudo[985]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:55:38 piaware sudo[985]: pam_unix(sudo:session): session closed for user root
Aug 27 14:55:38 piaware piaware[399]: Starting multilateration client: /usr/lib/piaware/helpers/fa-mlat-client --input-connect localhost:30005 --input-type auto --results beast,connect,localhost:30104 --results beast,listen,30105 --results ext_basestation,listen,30106 --udp-transport 70.42.6.191:8436:2542054443
Aug 27 14:55:39 piaware piaware[399]: mlat-client(998): fa-mlat-client 0.2.10 starting up
Aug 27 14:55:39 piaware piaware[399]: mlat-client(998): Using UDP transport to 70.42.6.191 port 8436
Aug 27 14:55:39 piaware piaware[399]: mlat-client(998): Listening for Beast-format results connection on port 30105
Aug 27 14:55:39 piaware piaware[399]: mlat-client(998): Listening for Extended Basestation-format results connection on port 30106
Aug 27 14:55:39 piaware piaware[399]: mlat-client(998): Input connected to localhost:30005
Aug 27 14:55:40 piaware piaware[399]: mlat-client(998): Beast-format results connection with ::1:30104: connection established
Aug 27 14:56:50 piaware piaware[399]: timed out waiting for alive message from FlightAware, reconnectingā€¦
Aug 27 14:56:50 piaware piaware[399]: multilateration data no longer required, disabling mlat client
Aug 27 14:56:51 piaware piaware[399]: fa-mlat-client exited normally
Aug 27 14:56:51 piaware piaware[399]: reconnecting in 72 secondsā€¦
Aug 27 14:56:51 piaware piaware[399]: mlat-client(998): Disconnecting from localhost:30005: Lost connection to multilateration server, no need for input data
Aug 27 14:56:51 piaware piaware[399]: mlat-client(998): Exiting on connection loss
Aug 27 14:58:03 piaware piaware[399]: Connecting to FlightAware adept server at piaware.flightaware.com/1200
Aug 27 14:58:03 piaware piaware[399]: Connection with adept server at piaware.flightaware.com/1200 established
Aug 27 14:58:04 piaware piaware[399]: TLS handshake with adept server at piaware.flightaware.com/1200 completed
Aug 27 14:58:04 piaware piaware[399]: FlightAware server certificate validated
Aug 27 14:58:04 piaware piaware[399]: encrypted session established with FlightAware
Aug 27 14:58:04 piaware sudo[1450]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:58:04 piaware sudo[1450]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:58:04 piaware sudo[1450]: pam_unix(sudo:session): session closed for user root
Aug 27 14:58:05 piaware piaware[399]: logged in to FlightAware as user hs0zed
Aug 27 14:58:05 piaware piaware[399]: site statistics URL: https://flightaware.com/adsb/stats/user/hs0zed#stats-109298
Aug 27 14:58:05 piaware piaware[399]: multilateration data requested
Aug 27 14:58:05 piaware sudo[1462]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:58:05 piaware sudo[1462]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:58:05 piaware sudo[1462]: pam_unix(sudo:session): session closed for user root
Aug 27 14:58:05 piaware piaware[399]: Starting multilateration client: /usr/lib/piaware/helpers/fa-mlat-client --input-connect localhost:30005 --input-type auto --results beast,connect,localhost:30104 --results beast,listen,30105 --results ext_basestation,listen,30106 --udp-transport 70.42.6.225:5582:766120354
Aug 27 14:58:06 piaware piaware[399]: mlat-client(1470): fa-mlat-client 0.2.10 starting up
Aug 27 14:58:06 piaware piaware[399]: mlat-client(1470): Using UDP transport to 70.42.6.225 port 5582
Aug 27 14:58:06 piaware piaware[399]: mlat-client(1470): Listening for Beast-format results connection on port 30105
Aug 27 14:58:06 piaware piaware[399]: mlat-client(1470): Listening for Extended Basestation-format results connection on port 30106
Aug 27 14:58:06 piaware piaware[399]: mlat-client(1470): Input connected to localhost:30005
Aug 27 14:58:07 piaware piaware[399]: mlat-client(1470): Beast-format results connection with ::1:30104: connection established
Aug 27 14:58:07 piaware piaware[399]: piaware (process 399) is shutting down because it received a shutdown signal (SIGTERM) from the systemā€¦
Aug 27 14:58:07 piaware piaware[399]: faup1090 exited with SIG SIGTERM
Aug 27 14:58:07 piaware piaware[399]: multilateration data no longer required, disabling mlat client
Aug 27 14:58:07 piaware systemd[1]: Stopping FlightAware ADS-B uploaderā€¦
Aug 27 14:58:07 piaware piaware[399]: fa-mlat-client exited with SIG SIGTERM
Aug 27 14:58:07 piaware piaware[399]: removing pidfile /run/piaware/piaware.pid
Aug 27 14:58:07 piaware piaware[399]: piaware (process 399) is exitingā€¦
Aug 27 14:58:07 piaware systemd[1]: Stopped FlightAware ADS-B uploader.
Aug 27 14:58:08 piaware systemd[1]: Started FlightAware ADS-B uploader.
Aug 27 14:58:09 piaware piaware[1487]: creating pidfile /run/piaware/piaware.pid
Aug 27 14:58:09 piaware piaware[1487]: ****************************************************
Aug 27 14:58:09 piaware piaware[1487]: piaware version 3.7.1 is running, process ID 1487
Aug 27 14:58:09 piaware piaware[1487]: your system info is: Linux piaware 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux
Aug 27 14:58:10 piaware piaware[1487]: Connecting to FlightAware adept server at piaware.flightaware.com/1200
Aug 27 14:58:11 piaware piaware[1487]: Connection with adept server at piaware.flightaware.com/1200 established
Aug 27 14:58:11 piaware piaware[1487]: TLS handshake with adept server at piaware.flightaware.com/1200 completed
Aug 27 14:58:12 piaware piaware[1487]: FlightAware server certificate validated
Aug 27 14:58:12 piaware piaware[1487]: encrypted session established with FlightAware
Aug 27 14:58:12 piaware sudo[1503]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:58:12 piaware sudo[1503]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:58:12 piaware sudo[1503]: pam_unix(sudo:session): session closed for user root
Aug 27 14:58:12 piaware sudo[1526]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:58:12 piaware sudo[1526]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:58:12 piaware sudo[1526]: pam_unix(sudo:session): session closed for user root
Aug 27 14:58:12 piaware piaware[1487]: ADS-B data program ā€˜beast-splitterā€™ is listening on port 30005, so far so good
Aug 27 14:58:12 piaware piaware[1487]: Started faup1090 (pid 1534) to connect to beast-splitter
Aug 27 14:58:12 piaware piaware[1487]: UAT support disabled by local configuration setting: uat-receiver-type
Aug 27 14:58:13 piaware piaware[1487]: logged in to FlightAware as user hs0zed
Aug 27 14:58:13 piaware piaware[1487]: site statistics URL: https://flightaware.com/adsb/stats/user/hs0zed#stats-109298
Aug 27 14:58:13 piaware piaware[1487]: multilateration data requested
Aug 27 14:58:13 piaware sudo[1535]: piaware : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/netstat --program --tcp --wide --all --numeric
Aug 27 14:58:13 piaware sudo[1535]: pam_unix(sudo:session): session opened for user root by (uid=0)
Aug 27 14:58:13 piaware sudo[1535]: pam_unix(sudo:session): session closed for user root
Aug 27 14:58:13 piaware piaware[1487]: Starting multilateration client: /usr/lib/piaware/helpers/fa-mlat-client --input-connect localhost:30005 --input-type auto --results beast,connect,localhost:30104 --results beast,listen,30105 --results ext_basestation,listen,30106 --udp-transport 70.42.6.191:8462:2480218437
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): fa-mlat-client 0.2.10 starting up
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): Using UDP transport to 70.42.6.191 port 8462
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): Listening for Beast-format results connection on port 30105
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): Listening for Extended Basestation-format results connection on port 30106
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 14:58:14 piaware piaware[1487]: mlat-client(1543): Beast-format results connection with ::1:30104: connection established
Aug 27 14:58:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter; 0 msgs sent to FlightAware
Aug 27 15:00:44 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:00:44 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:01:47 piaware piaware[1487]: mlat-client(1543): Beast-format results connection with ::1:30104: connection lost
Aug 27 15:02:18 piaware piaware[1487]: mlat-client(1543): Beast-format results connection with 127.0.0.1:30104: connection established
Aug 27 15:03:14 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:03:14 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:03:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter (0 in last 5m); 0 msgs sent to FlightAware
Aug 27 15:05:44 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:05:44 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:06:26 piaware piaware[1487]: mlat-client(1543): Beast-format results connection with 127.0.0.1:30104: connection lost
Aug 27 15:06:56 piaware piaware[1487]: mlat-client(1543): Beast-format results connection with ::1:30104: connection established
Aug 27 15:08:14 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:08:14 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:08:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter (0 in last 5m); 0 msgs sent to FlightAware
Aug 27 15:10:44 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:10:44 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Receiver status: disconnected
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Server status: not synchronized with any nearby receivers
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Receiver: 0.0 msg/s received 0.0 msg/s processed (0%)
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Server: 0.0 kB/s from server 0.0kB/s TCP to server 0.0kB/s UDP to server
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Aircraft: 0 of 0 Mode S, 0 of 0 ADS-B used
Aug 27 15:13:14 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:13:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter (0 in last 5m); 0 msgs sent to FlightAware
Aug 27 15:15:44 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:15:44 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:18:14 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:18:14 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:18:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter (0 in last 5m); 0 msgs sent to FlightAware
Aug 27 15:20:44 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:20:44 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:23:15 piaware piaware[1487]: mlat-client(1543): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Aug 27 15:23:15 piaware piaware[1487]: mlat-client(1543): Input connected to localhost:30005
Aug 27 15:23:43 piaware piaware[1487]: 0 msgs recvā€™d from beast-splitter (0 in last 5m); 0 msgs sent to FlightAware
pi@piaware:~ $

2

Didnā€™t you in your last post acknowledge that you need to check the airspy service:

sudo journalctl -u airspy_adsb --no-pager

Oh and enclose any log or code you post in ```, like this:
```
text
text
text
```

3

Okay, apologies, I had forgotten about any other checks, probably because it started working and was so happy :laughing:

Here is the output.

Aug 27 15:44:34 piaware airspy_adsb[1895]: Caught signal 15
Aug 27 15:44:34 piaware systemd[1]: Stopping Airspy ADS-B receiver...
Aug 27 15:44:34 piaware airspy_adsb[1895]: Decoding stopped
Aug 27 15:44:34 piaware systemd[1]: Stopped Airspy ADS-B receiver.
Aug 27 15:44:34 piaware systemd[1]: Started Airspy ADS-B receiver.
Aug 27 15:44:34 piaware airspy_adsb[6063]: Multi-threading is not supported in this version.
Aug 27 15:44:34 piaware airspy_adsb[6063]: Listening for asavr clients on port 47806
Aug 27 15:44:34 piaware airspy_adsb[6063]: Listening for beast clients on port 47787
Aug 27 15:44:34 piaware airspy_adsb[6063]: Acquired Airspy device with serial 466C64C82C604AC7
Aug 27 15:44:34 piaware airspy_adsb[6063]: Decoding started at 12 MSPS

Regards
Martin

4

You configured it wrong, the ports donā€™t match.
Change the airspy config to listen for beast on 29999.
Then it should work.

Iā€™m not sure what you are changing or doing that it would work and then stop working.

Seems you mixed the script and the manual guide.
They use different ports.

5

Okay thanks for the information. I think I should go back to the beginning and start again. I should be able to just use the script and not change anything.

Is there a suitable reset command I can use. Something that will remove, or undo, anything I might have dome and restore a clean state?
Can I just re-run the script command?

Thanks
Martin

6

Yeah the script will overwrite all the relevant configurations.
(Other stuff i do that doesnā€™t happen but as the settings are simple and you only need to run it if it doesnā€™t work it overwrites the configuration)

7

Okay, many thanks, itā€™s all back on track again.

Hereā€™s what I think happened. I fiddled with it, unnecessarily, clearly changing things without knowing what they would do but nothing broke, presumably because the changes I made were not acted on. Until the brown out that happened this morning, right about when the stats show it dropped out. Clearly when it restarted it read my messed up configuration and did what I had told it to do, which was basically to break it.

Learning by doing (or breaking)

Thanks again
Martin

8

Changing gain for example is fine.
Just donā€™t touch the network settings! :slight_smile:

Are you running the airspy without an LNA?
(Then leave the gain at 21)

What does this look like for you What is the Maximum Range I can Get? ?

9

What it looks like for me is that the circle generated for 10,000 feet is about what I can achieve for all aircraft even at 35,000 feet.

The indoor antenna is clearly the problem but now Iā€™m happy the thing essentially works and issues are mostly (all) of my own making I plan to work on something for outside.

Iā€™m not convinced the coaxial cable collinear works well, wrong mix of velocity factors, and Iā€™m pretty sure something simple with perhaps a bit more amplification will be more than enough once I get it above roof height even slightly. Longer term Iā€™m thing to put a pi+sdr in a box and mount it out on my tower at around 50 feet. Meantime I keep fiddling.

Martin

map1
map1890Ɨ604 166 KB

10

To get the full potential from the Airspy, you will need an LNA for 1090 MHz, i would recommend this one:

New Product: RTL-SDR Blog 1090 MHz ADS-B LNA

Best run it at 3 V to 3.5 V so it doesnā€™t get as hot.
Iā€™ve tested and it works fine down to 2 V or so.
A 20 Ohm resistor in series will work fine with a 5 V supply, resulting in a voltage under load of around 3 V to 3.5 V.
Then you just need a bias-t like this one Bias Tee Wideband 1mhz-3ghz for Ham Radio RTL SDR LNA Low Noise Amplifier 50vdc for sale online | eBay to couple the DC into the LNA.

And as a reference antenna it shouldnā€™t be too hard for you to build this:
QUICK SPIDER - No Soldering, No Connector

Thatā€™s a good baseline antenna.

11

The gain is dependent on the voltage. Donā€™t know if that is ā€œfineā€ for everyone.

12

Iā€™m not asking anyone to run it at 2 V.

At 3.3 V it has almost full gain, maybe a couple dB less.
But if you start with 30 dB amplification, a couple dB less isnā€™t a problem.

13

Yes, a simple ground plane is what I plan to try just sticking out on the balcony to start with, just want to gauge the in-building degradation.

Iā€™d prefer to mess around with building rather than just buying. I likely have most of the parts and can soon knock out a quick pcb with scored track striplines as necessary. Iā€™d like to know whats inside some of these commercial amps. My first try, using an MSA-02 MMIC has lots of gain, but lots of noise too. If the drive voltage drops it doesnā€™t affect the gain too much but as the amp current falls the noise level increases.

I wonder also if the cellphone signals are perhaps a problem for the SDR as well. Need to make a 1090 band pass filter.

The Airspy is too useful for other stuff though to dedicate for this job. Iā€™m pretty sure a $20 dongle will work well enough.

14

I have bought two of those myself, waiting for delivery:

https://www.qorvo.com/products/p/SPF5189Z

15

The rtl-sdr LNA is described on the page i linked i believe.

input ā†’ High pass filter ā†’ LNA first stage ā†’ SAW filter ā†’ LNA second stage ā†’ SAW filter ā†’ output

Designing high frequency PCBs requires quite some knowledge.
But if you just want to tinker, good luck, just donā€™t expect good performance :stuck_out_tongue_winking_eye:

One of the problems:
Even the components will likely cost you more than just getting that LNA.

And the rtl-sdr dongles are even more susceptible to interference, so the LNA is even more importatnt.

16

The filtered amp does look very good and truly its an impressive price, I can definitely see getting one.
The board design for simple amps and filters seems not too awkward and there is some online information that can be extrapolated to good effect. Iā€™ve learned a lot recently, of course never enough. The GaaS-pHemt that SoNic referenced looks a pretty nice device.

My whole work life has been in air traffic ground comms so Iā€™m no stranger to 100-400MHz, 1GHz is definitely more demanding but only because it gets a bit smaller.

17

Itā€™s probably not too complicated.

If you can source good SAW filters and amps, iā€™m sure the rest falls in place.

As far as i understand a 2 stage amplifier design helps in avoiding overload by out of band signals while providing lots of amplification.

If you are doing your own PCB anyway, you can consider building an amplifier board with an antenna, like this:

Donā€™t know about the pitfalls of that though.
There are some Chinese clones of this antenna floating around, this below is the original i believe: https://forum.planefinder.net/threads/very-small-pcb-active-antenna-210-mm-high.224/

18

Yes this looks very interesting. Iā€™ve seen the Chinese ones on Lazada here.
The original F5ANN/F1OPA plans including schematic and board layout are on the web though here
https://sites.google.com/site/vincentf1opa/descriptions/antenne-active-1090mhz

The 2 stage amp is probably the best compromise. A bit of gain first to overcome the filter losses then a bit more gain to drive it down the lossy coax.

19

Under $9 for 2 of them:

20190827_110522
20190827_1105221131Ɨ802 218 KB

20

These are the GaaS pHemtā€™s?

I like the look of this French integrated antenna. The PSA4-5043+ looks like a winner too, also a pHemt device I think, 0.9dB noise figure around 1GHz and about 18dB gain per device less about 3dB for the filter and maybe another 3dB for the coax to the sdr.