Component failure diagnosis

Does anyone know of a quick way to diagnose which particular component has failed in a setup? until last night/this morning, I was getting fairly consistent results, then today my results have close to flat lined. I have the Flight Aware Antenna → Flight Aware filter → Paladin Tools 9672 In-Line Amplifier → DirectTV Power Inserter ->Piaware box running Dump1090 Mutability(stable, not the dev version). I just took out the filter wondering if it had gone bad or one of the connections… my next attempt will be with the in line amplifier, see if that’s failed or something. Is there a better way to test than removing components from the chain?

I readded the filter and swapped the power inserter with one I had for another project… that seems to have restored the amount of aircraft normally seen during timeframes… Is there an easy way to inspect/troubleshoot the replaced unit, or just chunk it and get another? I’m surprised it seems to have failed since it’s been running continously for about 2 months so far.

And now again, it appears to not be working… grrr… this is driving me nuts…

Check the power supply voltage. There are USB voltage and current monitors that show the voltage and current demand of the attached USB device. The problems I have encountered were due to these power supplies struggling to keep 5V when loaded with the raspberry, wifi, SDR and USB hub. When the voltage drops below 4.75 volts then you may see more faults. I purchased the USB Doctor from eBay and Adafruit.

Flight Aware Antenna → Flight Aware filter → Paladin Tools 9672 In-Line Amplifier → DirectTV Power Inserter ->Piaware box running…

If I can assume you are using the DirecTv inserter SWM unit (found all over Ebay for $9-$12) then the green pilot light should tell you if it is working. Using a DVM should show 24VDC (without a load) on the red tipped connector.

I had one fail after unplugging the unit to redress the antenna wire. Upon plugging it back in…no light, no voltage. I have purchased another only because it is easy to mount in the now existing holes. While waiting for the replacement I took the injecter module out and attached one of the many power bricks in my collection to it. I use a HABAMP LNA that accepts 3 to 26 volts so finding a supply wasn’t too hard.

I am suspicious of these DirecTv units. Did a bad batch get out and end up on Ebay? Maybe they failed Hi-Pot testing and are more prone to ESD or inrush current damage.

Well annoyingly it seems the other power supply is doing the same thing as the other one… worked for an hour then has faded away(yesterday when I fiddled with all the connections on the original, it seemed to work for an hour then faded away)… Would the in-line amp failing cause issues like this, or something in the Pi? This system had been running completely stable from when I started it up and have augmented it since January, until yesterday.

Wouldn’t be the Pi.

Swap the amp if you have a spare (with the direct TV unit disconnected). while the amp is disconnected put a meter on Ohms on the cable … check you no contact between the core and the shield (in case the insulation is full of rainwater)

If the antenna has developed a connection to ground, you will be pumping 40.6 watts of energy into the antenna system that will be heating up something (from the injector nameplate specs).

I took out the amp and power injector earlier, and it’s still doing these massive spikes, one hour close to normal, then the next close to 0, and repeated and now clsoe to flat lining… at this point I have no close what could be causing this. Any ideas?

Please advise us of the type of cable you are using for the down lead.

FWIW, I noticed the input voltage of the Paladin Tools 9672 In-Line Amplifier is 12-18VDC. You did not mention the model number of the DirecTv inserter but the one many of us use is the SWM version that is rated at 21VDC. There is a possibility you have overheated the coax if you have this combination. If you haven’t done so already, you may want to try a different down lead. RG6 is recommended when DC is on the cable.

I’m using RG6 as far as I can remember.

24v into an amplifier rated at 18v max - that would be pushing it.