Radarspotting

Mode-S Receivers => DVB-T Dongles and Self-Assembly Receivers => Topic started by: Bethsalem on September 04, 2015, 12:36:03 PM

Title: Tinkering with your Dongle setup
Post by: Bethsalem on September 04, 2015, 12:36:03 PM
I just can't leave well alone...

I've attached a picture of my current dongle setup. By attaching an LNA and LTCC 1090MHz filter just in front of this newly revised version of the venerable R820 dongle I have more than doubled my frame-rate, and much more importantly, the number of aircraft on my screen.

For example, using the dongle alone I'm seeing 225 frames per second and 35 aircraft on screen.

With the LNA and filter I'm seeing 550 frames per second and 55 aircraft on screen.  :)

The total cost of this setup, new dongle, LNA, tablet charger, connectors, boxes and filter, but excluding antenna, coaxial cable and laptop, was about 75 euros including total postage.

Not a bad expenditure for the increase in sensitivity which now rivals my Beast setup, which cost considerably more.

[Attachment deleted by Admin to save file space]
Title: Re: Tinkering with your Dongle setup
Post by: Radio2.0 on September 06, 2015, 03:28:32 PM
I have the LNA to and its rubbis. There are better one the marked. The are powert by an modified Dongle so the LNA could be next to the Antenna.
Title: Re: Tinkering with your Dongle setup
Post by: Anmer on September 06, 2015, 03:48:37 PM
Quote from: Radio2.0 on September 06, 2015, 03:28:32 PM
I have the LNA to and its rubbis.

Thanks for sharing your experience.
Title: Re: Tinkering with your Dongle setup
Post by: IanH on September 06, 2015, 04:47:14 PM
I've got an LNA as well. Not sure that it is rubbish. OK, I did not have any success with it, but I don't know what settings to use on the dongle. Probably overloaded the input to the dongle with the default settings! Didn't have the time to mess around with it.

@Bethy - what software are you using to display the output from the dongle? What settings to you use for the gain with the LNA connected?

I'm off on holiday tomorrow so I'll give the LNA a try again when I come back
Title: Re: Tinkering with your Dongle setup
Post by: Radio2.0 on September 06, 2015, 06:44:41 PM
I use Auto gain.
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on September 06, 2015, 07:49:28 PM
Quote from: IanH on September 06, 2015, 04:47:14 PM
I've got an LNA as well. Not sure that it is rubbish. OK, I did not have any success with it, but I don't know what settings to use on the dongle. Probably overloaded the input to the dongle with the default settings! Didn't have the time to mess around with it.

@Bethy - what software are you using to display the output from the dongle? What settings to you use for the gain with the LNA connected?

I'm off on holiday tomorrow so I'll give the LNA a try again when I come back

Hi Ian

On it's own the LNA doesn't do much, so Radio 2.0 has a point. It increases the noise as well as the signal so you are no better off. Likewise, Adam's bandpass filter, on it's own, doesn't improve things either.

However..... if you pair this LNA with Adam's bandpass filter, putting the LNA before the filter, then, boy, do things improve dramatically! Even more so if you set the Dongle's gain around the 30dB mark.

As regards software, I'm using VRS as I haven't yet found a way to combine the Dongle's feed with the Beast's in order to display both on PP.

So in conclusion, LNA and bandfilter used separately equals no noticeable effect on sensitivity.

Combined as antenna-LNA-bandpass filter-dongle-pc, equals getting close to my Beast in terms of range and number of aircraft detected.
Title: Re: Tinkering with your Dongle setup
Post by: IanH on September 06, 2015, 08:07:20 PM
Thanks - I've ordered the dongle. Next will be the filter  ;D
Title: Re: Tinkering with your Dongle setup
Post by: Radio2.0 on September 06, 2015, 08:39:17 PM
if you are interested in filter: http://www.hftechnik.at/produkte/
QuoteLikewise, Adam's bandpass filter, on it's own, doesn't improve things either.
In my cache the Filter i now use give a huge different between nothink and filter.  ;D
Before i cant get any Signal from the Airport now i see quite all.
Quoteputting the LNA before the filter, then, boy, do things improve dramatically!
In my chase its different. I put the Filter before the LNA. Otherwise i get ~10%.
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on September 09, 2015, 12:19:10 PM
Quote from: IanH on September 06, 2015, 08:07:20 PM
Thanks - I've ordered the dongle. Next will be the filter  ;D

Adam's still got filters in stock. Also FlightAware are offering a new 1090MHz bandpass filter. I've ordered one and will report on its performance in due course. The CosyCave website is up and running again, and the LNA, both USB and Bias T powered variants, are currently in stock.
Title: Re: Tinkering with your Dongle setup
Post by: Barnsley Spotter on September 27, 2015, 08:29:54 AM
Bethsalem,

Are the four way boxes ip65 rated?

Im returning to the dongle whilst the sbs3 is being fixed.
Title: Re: Tinkering with your Dongle setup
Post by: IanH on September 27, 2015, 12:01:17 PM
QuoteAlso FlightAware are offering a new 1090MHz bandpass filter

RTL-SDR dongle has arrived - took about 3 weeks to get here. Already have the CosyCave LNA.

Where on the Flightaware site does it mention 1090 filters for sale?
Title: Re: Tinkering with your Dongle setup
Post by: Radio2.0 on September 27, 2015, 12:59:19 PM
www.hftechnik.at filter for sale.
or if you want a cheap i can offer you an good for 30€.  ;D
Title: Re: Tinkering with your Dongle setup
Post by: Anmer on September 27, 2015, 02:39:45 PM
Quote from: IanH on September 27, 2015, 12:01:17 PM
Where on the Flightaware site does it mention 1090 filters for sale?

They're sold via Amazon.com but appear to be out of stock:

https://discussions.flightaware.com/post181483.html?sid=17697119f91ee9ed66ff21e787acedcc#p181483
Title: Re: Tinkering with your Dongle setup
Post by: IanH on September 27, 2015, 04:42:27 PM
Thanks - found them on eBay after eventually finding a link under the Piaware instructions.

http://www.ebay.co.uk/itm/141748987047?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on September 27, 2015, 05:06:29 PM
Quote from: Barnsley Spotter on September 27, 2015, 08:29:54 AM
Bethsalem,

Are the four way boxes ip65 rated?

Im returning to the dongle whilst the sbs3 is being fixed.

No, only IP54, but I could have bought weatherproof, exterior boxes, which were IP67 rated, so you should be able to source higher rated four-way boxes in the UK without much problem from a diy store.
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on September 27, 2015, 05:13:35 PM
Quote from: IanH on September 27, 2015, 12:01:17 PM
QuoteAlso FlightAware are offering a new 1090MHz bandpass filter

RTL-SDR dongle has arrived - took about 3 weeks to get here. Already have the CosyCave LNA.

Where on the Flightaware site does it mention 1090 filters for sale?

It's from here Ian, http://www.rtl-sdr.com/new-product-from-flightaware-a-1090-mhz-bandpass-filter-for-the-rtl-sdr/
Title: Re: Tinkering with your Dongle setup
Post by: IanH on October 03, 2015, 12:12:37 PM
Doing a search for alternatives, I found this:

http://ava.upuaut.net/store/index.php?route=product/product&product_id=85

LNA plus filter in an aluminium case (looks like a PlaneGadget Radar!). £36 plus £5 postage.

Which way to go?
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on October 22, 2016, 03:16:25 PM
Quote from: Bethsalem on September 04, 2015, 12:36:03 PM
I just can't leave well alone...

I've attached a picture of my current dongle setup. By attaching an LNA and LTCC 1090MHz filter just in front of this newly revised version of the venerable R820 dongle I have more than doubled my frame-rate, and much more importantly, the number of aircraft on my screen.

For example, using the dongle alone I'm seeing 225 frames per second and 35 aircraft on screen.

With the LNA and filter I'm seeing 550 frames per second and 55 aircraft on screen.  :)

The total cost of this setup, new dongle, LNA, tablet charger, connectors, boxes and filter, but excluding antenna, coaxial cable and laptop, was about 75 euros including total postage.

Not a bad expenditure for the increase in sensitivity which now rivals my Beast setup, which cost considerably more.

Just over a year later and I've updated my setup thus (have a look at the attached photo)

The new step us consists of > Antenna - FM Band Stop Filter - LNA - 1090MHz Band Pass Filter - Prostick(LNA plus R820T2 dongle combo)

I'm getting roughly 10% more reported positions according to my PiAware stats page.

I've attached a couple of screenshots showing how this new dongle setup (Reus889) is outperforming my Beast (Reus890), 67 aircraft (dongle) versus 47 aircraft (beast) which is quite a remarkable feat, I think.

[Attachment deleted by Admin to save file space]
Title: Re: Tinkering with your Dongle setup
Post by: Anmer on October 22, 2016, 03:46:09 PM
Thanks for sharing.

How long is your coax?

And what WiFi USB device is that?

And what happens if you remove the filters and amp?
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on October 22, 2016, 11:05:59 PM
Unfortunately the coax cable is 17 metres in length.

The WiFi USB device is the official Raspberry Pi WiFi dongle.

If I remove the FM band stop filter and the first LNA, then the aircraft seen dips to about 20% below Beast value. So for illustration sake, if the Beast is showing 50 aircraft, the Dongle, sans first filter and first LNA, is showing 40 aircraft.

If I return the setup back to normal R820T dongle, plus 1090MHz band pass filter, plus powered LNA, then I'm seeing about 10% more aircraft than the Beast, so for illustration sake 55 aircraft (Dongle) versus 50 aircraft (Beast).

I've experimented with every possible configuration, and this setup with two filters and two LNAs, in the sequence I've set them up in, works the best by far, consistently out performing the Beast.
Title: Re: Tinkering with your Dongle setup
Post by: Radio2.0 on October 22, 2016, 11:22:00 PM
do you play with the Gain features?
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on October 22, 2016, 11:26:39 PM
No, because I've attached the 1090MHz band pass filter immediately in front of the ProStick, and in this configuration FlightAware say that you can leave the gain on automatic.

I have messed around with changing the gain just out of curiosity, but the results were always worse than when I left the gain setting on its default setting.
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on October 27, 2016, 10:26:11 AM
I've been using the new setup since last Friday evening (21st Oct) and I've noticed the greatly increased number of positions reported. I'm not seeing many extra aircraft, but the ones I do I'm seeing for longer. The range I can detect out to has only increased slightly, but the signal strength is stronger.

Stats courtesy of FlightAware.

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Title: Re: Tinkering with your Dongle setup
Post by: Anmer on October 27, 2016, 10:43:12 AM
That's typically what I experience with an amp.  Similar range with more contacts for longer.

Your setup is working well.
Title: Re: Tinkering with your Dongle setup
Post by: Bethsalem on October 27, 2016, 04:26:35 PM
I'd read on one of the Reddit subforums that using a "two amps, two filters" system was increasing the likelihood of receiving a usable signal for Outernet and for Inmarsat, so I thought I'd give it a go for ADS-B.

It certainly is an improvement on my previous setup, but only if I link the components together in the way I have 

FM bandstop filter, LNA, 1090MHz bandpass filter, finally ProStick (LNA + R820T2).

No other combination gives the same result.