Simple ADSB hardware question

[thekubiaks]

I am running ADSBScope through an RTL2832/E4000 based dongle with external 5dBi antenna.  I have seen framerates as high 8800 frames/minute.

Question is, if I am able to process this high a framerate, is there any advantage to getting a Mode-S Beast??   My region has multiple ADS-B FR24 tracking locations.  Everything that FR24 is showing from the other sites is showing up on my ADSBScope.  It seems like I have sufficient processing power.  Thoughts??  thx

[Anmer]

Ignoring framerates for a moment, what range are you getting and how many aircraft are you receiving?

[thekubiaks]

I'm getting 100nm in 3 quadrants and about 175nm in the fourth quadrant.  I routinely see 20-30 aircraft displayed.  one number I don't understand is at the bottom of Radarscope.  Next to frame rate is a number in brackets.  when ADSBScope says 8800 frame rate, the number in brackets might be (140).  Would this be frames/sec?  thx

[Anmer]

Thanks.

Can you post a screen capture of these message rates?

[thekubiaks]

sure.  I'm on the road right now but will be able to do so within 48 hours.

so, back to the op,  do you think a Mode-S Beast would help me improve rates?  Thx

[Anmer]

I don't see the value of measuring and comparing frame rates.

What matters is how many aircraft messages are being received and decoded.  And in my experience, the antenna location adds most value and my DVB-T dongle compares favourably with the SBS-1/3 and Mode-S Beast on the same antenna.

[thekubiaks]

I'm really not trying to start an argument.  I simply want to know if I will see more ADSB aircraft or what is the advantage of running a ModeS Beast, SBS1 or SBS3 over the E4000 dongle.I m currently runnong. given my current ranges and rates.  thx

[Anmer]

I'm really not trying to start an argument.[/quopte]

Nor am I. 

Without knowing where your antenna is positioned and where you're located, I can't tell if you'rer getting the optimum results from your current setup.

In my experience, another receiver may deliver a higher frame rate but that doesn't equate to more aircraft messages.

I repeat, side by side on the same external antenna, the Dongle delivers comparable results to a Beast and other specialist receivers.  How long a cheap dongle lasts and whether it comes with technical support is a different topic.

[thekubiaks]

Here are the screenshots you asked for:

My 5dBi antenna by lz2rr is mounted 30 feet above the ground and 10 ft above my chimney but it still doesn't have a completely unobstructed view in all directions.

http://www.ebay.com/itm/190887916388?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

It looks like I got some max range tracks:
SOUTH = 195NM
WEST = 152NM
NORTH = 132NM
EAST = 60 – 110NMse

ADSB Sharp 1.0.11.1, ADSBScope 2.6f3 Win7, FlightRadar24 [T-KLOU3]

Framerate in the 8000's and about 150 frames/sec

Would I get more range if I replace the RTL2832/E4000 with a ModeS Beast, SBS-1, or SBS-3??  Any news on Radarcape??

Thx for the replies.....




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[Anmer]

Thanks for the screenshots.

My guess is an SBS-3, Beast or RadarCape could deliver some extra messages and may extend your range marginally.

It really depends what you want to achieve?  I doubt you're "missing" local traffic within range of your antenna (check FR24).

The only thing that I can guarantee is that you will be spending a lot more dollars.  And you may be disappointed.

Having compared a cheap DVB-T USB stick to all avaliable receivers, I'd have been disappointed if I'd started with a $20 DVB-T and then spent $800 on a replacement to gain a higher frame rate.

For me the data presentation software and database is equally important, as too is receiver reliability.  I hear of many DVB-T's failing after a couple of months use. 

[kered]

You can get a lot of $20 DVB-T USB sticks for $800 ( 40 +/-) i have also read that running 2 dongles in tandem with the rtl1090 software improves things too.(not got round to trying it yet)

My beast does pull in more signals especially in bad weather but the difference is not as large as one would expect considering the price difference. Reliability as Anmer mentioned could be a problem but up till now mine are working fine. I did have to send the beast for repair though as the antenna static protection hadn't been installed and blew the amps.

Maybe a preamp might even things, and definately good cable and antenna make a difference.

[thekubiaks]

Yes,
    I do have an LNA I am getting ready to hook up.  Perhaps this will increase my range somewhat, I'll report back ASAP.   

http://lna4all.blogspot.com/

[9a4qv]

So is the LNA4ALL good for nothing or worth the money?
Reading the comments, I can just said that any DVB-T dongle can have side/side performance with any big bucks ADS-B receiver, of course using the proper setup.

I do have the DVB-T dongle with E-4000 tuner and can get the planes up to 400km radius from my location in Croatia, so up to Munich using just a simple ground plane homebrew antenna.
My location is nothing special, some 260 ASL.

I did measure the sensitivity of the DVB-T dongle with the E-4000 tuner and there is no problem.
The trick is in the filtering...

have fun
Adam

[Bethsalem]

You can get a lot of $20 DVB-T USB sticks for $800 ( 40 +/-) i have also read that running 2 dongles in tandem with the rtl1090 software improves things too.(not got round to trying it yet)

My beast does pull in more signals especially in bad weather but the difference is not as large as one would expect considering the price difference. Reliability as Anmer mentioned could be a problem but up till now mine are working fine. I did have to send the beast for repair though as the antenna static protection hadn't been installed and blew the amps.

Maybe a preamp might even things, and definately good cable and antenna make a difference.

I have put up another antenna on the other side of my apartment, linking it to another R820T dongle, and then chaining both dongles to the one computer. A cheap and very effective way of getting improved coverage without spending a fortune.

Stephen

[thekubiaks]

Adam,
     How are you filtering??  I just hooked a LNA4ALL up to my E-4000 dongle.  I verified that the LNA was pulling the proper current & volts (12.3VDC).  My framerate dropped from 8400 to about 1400.  My reception ranges dropped by 50%.  It was as if the processor was choking on noise???  maybe it was something else but when I took the LNA back out of the system, my framerates and ranges jumped back up to normal.  Thanks

So is the LNA4ALL good for nothing or worth the money?
Reading the comments, I can just said that any DVB-T dongle can have side/side performance with any big bucks ADS-B receiver, of course using the proper setup.

I do have the DVB-T dongle with E-4000 tuner and can get the planes up to 400km radius from my location in Croatia, so up to Munich using just a simple ground plane homebrew antenna.
My location is nothing special, some 260 ASL.

I did measure the sensitivity of the DVB-T dongle with the E-4000 tuner and there is no problem.
The trick is in the filtering...

have fun
Adam