One thought - for when I start putting the HabAmp back in - all things being equal (non-faulty usb cable etc), should the Rpi2 be able to consistently output the 5v the HabAMp needs, over one of the onboard USB’s?
Only other thing plugged in via USB is the dongle itself.
Using your known good hardware config without habamp, have you tried swapping the mcx pigtails to see the if they are both good ?
I would feed the habamp from an external supply and swap out the USB power lead too.
I’m using habamp, no problems other than setting the dongle gain which is taxing.
No the sat amp psu is more than likely 12-18v and the habamp regular version will only accomodate 5vdc on the bias tee.
I have a special edition version of the habamp, with 5-26v on the bias tee.
Anthony at nevis/uputronics adds some components (voltage regulator) to the stock version at customer request.
I can power mine via 5v USB or 5-26v via coax.
Currently on test station powered via mini usb socket on the amp by a ipad ac mains charger which is 5v @ 2a and usb to mini usb lead.
I selected the ipad charger as I know its a high quality psu unit and rated at 2amps.
It may be like using a sledgehammer to crack a nut though as the habamp needs just 56ma !
cy80rg: With just the dongle, HabAmp and antenna. Try viewing the live map and when you see aircraft being tracked try removing power from the amp only. Do you see any change? I see aircraft drop off and the message rate drop but not all. Just something to try to see if the amp is trying to work.
You could try hooking up the HabAmp to a dongle and computer running standard SDR software, and see what the thing does with the signal and noise floor in the waterfall, maybe with a known-strong signal like a nearby fm station.
EDIT: Realized you have the filtered version so it’s not going to do a lot of good outside of 1090mhz. Still - you could visualize the ADSB signal and noise floor in an SDR# waterfall, or perhaps the RTL1090 sisex window. Just a thought.
Took my HabAmp to Anthony last night - to confirm, there was no fault whatsoever with Anthonys’ product.
Anthony ran the amp through his spectrum analyser and all performed as expected.
Turns out the issue was my SMA to MCX pigtail wasnt actually the one i’d ordered! (it didnt have the center pin - so was either broken or an rp-sma, afair).
Anyway, all in and working now - with the amp running directly off the RPi usb power.
Set the gain in mut down to 44.5, and get the stats below, looks pretty good!
Peak level looks rather high, so I’ll tweak gain down a bit more tonight…
Just to check, I take it that with the SAW filter in the amp, there’s no point putting the “inline combiner” filter on the ant to “get more filtering”?
I believe the only way an additional filter would help is if I worked out what freq the noise was on, then used a filter specific to that freq?
Anyway, here’s my stats so far, comments and suggestions more than welcome!
If it makes you feel any better, when I was first getting started I ordered a RP-SMA to SMA adapter to use an N-type to RP-SMA cable I had on hand for the Flightaware 1090 antenna…
Results were not good - Seemed like the antenna was junk so I kept using the beercan, **until an embarrassingly long time later when I realized the ADAPTER i ordered was the wrong polarity. The SMA end was going to the RP-SMA connector on the cable and the RP-SMA end was going to the SMA connector on the filter **
So this was actually adding an extra non-connection in the signal path, and I was still getting 50 mile range.
Nothing a few bucks on amazon and a bit of embarrassment couldn’t fix.