Aussie Feeders

[Ressy]

No worse than the A3 I have now, with it's N connector and SMA at the dongle end. one 50 to 75 transition ain't too bad, it's only if you get multiples.

or try transmit, then you'll notice it

But seriously, you can have a degraded signal, I had a "half dangerous" neighbor a few years back (dangerous as in a little bit of knowledge can be dangerous in the wrong hands LOL) did his new TV antenna, went to tricky dickies and just bought "thin tv looking like cable" upon my inspection from a distance it looked like rg58, close up confirmed it, I had about 20 odd metres of rg59 left over at home, more than enough for his needs and since I redid my place with rg6 I wasn't going to need any great lengths of it again, so we replaced it and voila no more signal fading to snow, he even had a snowy ch31 turn crystal clear.

So if it behaves like that a lower freqs which are more tolerant, it stands to reason there's a good few DB loss and should affect the higher freqs equally.

I have often thought of using one of the spare antenna ports on my wifi access point and plugging into my ADSB coco briefly one afternoon to see what coverage I can get off it (like to the park 350 mtrs away), it is an rg59 8 element coco in pvc, don't have access to a scope to verify where its centre frequency is, but should be somewhere close enough for adsb given it works pretty well considering where it is, and whats around it.

[rodeo]

Hmmm..... Looks like T-YSSY51 is feeding crappy data again - SSM1 (7CF7CA squawk 7712) is being reported by it again ....

t-yssy51.jpg

[bhaal]

sure it says DVT-B RTL's which implies 75 ohm

I know this is a couple of weeks old now, but aren't most/all the RTL-SDR dongles 50 ohm input?

Also, Anyone have friends in Redcliffe QLD who wouldn't mind hosting a Pi and antenna? There seems to be a big low altitude dead spot between me and Brisbane city... Need more Pi's with MLAT support...

[Ressy]

I know this is a couple of weeks old now, but aren't most/all the RTL-SDR dongles 50 ohm input?

Also, Anyone have friends in Redcliffe QLD who wouldn't mind hosting a Pi and antenna? There seems to be a big low altitude dead spot between me and Brisbane city... Need more Pi's with MLAT support...

The original, and still the far best feeder in SEQ, T-YBBN1, I wont reveal his location in case he does not want it bandied around, but trust me, he has far better low level coverage then any other feeder around, he saturates the area you are talking about (he's almost ground level at TYCAB, YBSU, and has ground at YBBN), so when FR24 discover a way to accept mlat data off normal users, that area will no doubt improve for mlat.

and no, dongles are designed for DTV (the fact most of them have a chipset that allows about 25Mhz to 1.8Ghz is pure luck for us) and are 75 ohm

[bhaal]

The original, and still the far best feeder in SEQ, T-YBBN1, I wont reveal his location in case he does not want it bandied around, but trust me, he has far better low level coverage then any other feeder around, he saturates the area you are talking about (he's almost ground level at TYCAB, YBSU, and has ground at YBBN), so when FR24 discover a way to accept mlat data off normal users, that area will no doubt improve for mlat.

It's not really a matter of figuring anything out, the current Pi only MLAT feed is just a trial when they know it's reliable they will work on getting the other feeding software to work. Thing is, I don't normally watch the radar via FR24, I watch my own VRS, I see far more aircraft (and as you now know) due to the fact that FA's mlat software sends positions back to the local dump1090 or can make a port available to feed VRS directly, which is what I do... So keeping that in mind is why I was asking about anyone in Redcliffe.. And the reason for Redcliffe is because it's far enough away from me here in Kallangur that it will help the very low level MLAT. My radar is only about 2mtrs above the peak of my single storey house, yet I can *almost* see ground level at YBBN, my dump1090 shows -150ft before I lose the signal, I get down to -25ft for YRED and ~50ft at YCAB... So I get a reasonable amount of low altitude signals, problem is, not enough PiAware feeders with the same view as me to help...

Not sure why I get given negative values from the aircraft, but it does, but I cannot see the planes ON the tarmac..

I am planning on raising my antenna another 3-5mtrs above it's present height, just have had the time to figure out the best way and do it (I have more than just an antenna on the roof). I am hoping that extra little bit of height will be enough to see ground levels at the 3 AP mentioned above...

and no, dongles are designed for DTV (the fact most of them have a chipset that allows about 25Mhz to 1.8Ghz is pure luck for us) and are 75 ohm

Oh.. Weird, because the little antennas that come with them are 50ohm ... And I am sure I've read elsewhere that the inputs are 50ohm, noting also I've seen other antennas where people have done ohm match transformers etc, like on this page http://www.balarad.net/ ....


Ok, my next thing which I had forgot to mention.. I recently acquired some cheap (that's the problem I know) dongles with R820T2 chips, hoping they might give off a better signal.. Sadly, in this incantation they do not, in fact slightly worse... At the same time as I was changing over sticks I thought I would also throw in one of my Pi2's ... Well.. Didn't that end badly... I lost about 30% of my signal quality, not entirely sure why, but yeah, didn't matter which dongle I used, it was just crap... So, back to the Pi B+ till I can solve that problem on a test rig down the track... Anyone else experienced this problem?

[rodeo]

At the same time as I was changing over sticks I thought I would also throw in one of my Pi2's ... Well.. Didn't that end badly... I lost about 30% of my signal quality, not entirely sure why, but yeah, didn't matter which dongle I used, it was just crap... So, back to the Pi B+ till I can solve that problem on a test rig down the track... Anyone else experienced this problem?

Interesting ! I haven't but then again I've only ever used Pi2's ..... and my ADSB Pi2 is sitting right on top of my NTP Pi2 as well.... I have a B+ sitting around doing nothing, I'll image a SD card and give it a whirl and see if I notice any difference. Will be funny if I have to revert back to a B+ for the ADSB rx !!

Cheers,

Andrew

[bhaal]

Interesting ! I haven't but then again I've only ever used Pi2's ..... and my ADSB Pi2 is sitting right on top of my NTP Pi2 as well.... I have a B+ sitting around doing nothing, I'll image a SD card and give it a whirl and see if I notice any difference. Will be funny if I have to revert back to a B+ for the ADSB rx !!

Cheers,

Andrew

Was this something were doing today or just when there is spare time?

[bhaal]

So it seems NSW are getting a few more leased air support for the coming bush fire season..

2 x Air Tractor AT-802's took off from YBBN not long ago heading south, I am only guessing their have been equipped as water bombers though, haven't seen a photo of them yet and I don't think YBBN Spotters got one :/

And just a little while ago, Omi-Air's DC10-30 Air tanker with NSW Rural Fire Brigade badges on it landed at YBBN on it's way to NSW...

Hopefully you guys don't need them! *fingers crossed*
arethesetourists.png
isthereanairshow.png

Link to YBBN Spotters image: https://scontent.fbne1-1.fna.fbcdn.n...92297825_o.jpg

[rodeo]

Was this something were doing today or just when there is spare time?

Definitely spare time !!! ie not high on the priority list (or correctly, on SWMBO's priority list ....)

[YSWG]

So it seems NSW are getting a few more leased air support for the coming bush fire season..

2015/16 is predicted to be a bad season with El Nino and after the rather "quite" season last year. 2014/15 fire season did have some big fires but far fewer than in previous years.

The C130 and DC-10 trial is happening at a good time, though not sure if they will return for the 2016/17 fire season.

N3079T and N3080T are currently in Ballarat, temporary manufacturer registration.

[rodeo]

If you are active over on the FA forums you will have possibly seen this:

Piaware 2.1-3 is now available.

The default port for multilateration results has changed

Piaware now sends mlat results to port 30104 by default. This change is to try to avoid accidentally feeding mlat results to a dump1090 that is not mlat-aware and may forward the results on unexpectedly (e.g. to other feeder software that doesn't expect to see them).

I've done the update and changed it back to sudo piaware-config -mlatResultsFormat beast,connect,localhost:30104 from bhaal's suggested -mlatResultsFormat "basestation,listen,31003" so here's hoping......

Andrew

[rodeo]

Have just now changed it back ...... I think I ended up feeding FR with crap :-( was showing a REX Saab340 that I know should have been a MLAT only with my radar ident.

[Oblivian]

Hrm. That breaks stuff if you don't change mutability too it seems

mlat(17926): Beast-format results connection with localhost:30104: [Errno 111] Connection refused

[rodeo]

Hey all,

I've just changed dump1090-mutability to Oliver's 1.15~dev version which doesn't on-feed FA generated "synthetic MLAT" back to FR. All appears to be well as far as I can see.

If anyone sees any funny MLAT data being fed by me, can you please let me know !!

Cheers,

Andrew

[val367]

Hi all

Just thought I would drop a quick note to say hi, I'm from Perth and have just set up a little usb dvb-t connected to my windows machine. Hopefully it will start seeing things (provided I haven't messed up the antenna too much). I tried getting my pi working but it looked to have a problem with the USB and didn't seem to connect. So I shelved that for the minute and have fired it up on the trusty windows machine .

Looking forward to learning more.

Cheers Val
(T-YPPH31)