DVB antenna or 1090MHz specific?

[Mat]

Just ordering bits from China. Is everyone just using the stock DVB antenna (presumably tuned around 700MHz) for the ADS-B receive or is it worth ordering a 1090MHz specific one?

[stephenmelody]

I ordered this one, I know it's big and long but from my house in Nottingham, I can pick up CAT overhead Brighton...

http://www.ebay.co.uk/itm/311367816597

I've ordered the little one from China, when it arrives I'll see if it's got the same range / performance.

Went flying with it today, could spot the CAT around EMA before I could see them with my eyes... was helpful, but they're in CAS.

I'm hoping to get some proper testing with the other side of the device at some point.

[stephenmelody]

This is an example of what I see...

[rg]

I went for a 95 - 1100 mhz antenna https://www.sinotel.co.uk/index.php?main_page=product_info&cPath=14&products_id=141 on the dvb dongle.  Worked no better that the antenna  that ships with the ARF board and is heavier so will probably go with the wirelessthings antenna even though is states 868-915mhz...you obviously  need an mcx  to sma adaptor...

[trapdoor]

This is the one I use for the ADS-B Rx...

http://www.ebay.co.uk/itm/361362426353

Now, bearing in mind I'm on the English side of the Bristol Channel, I have been able to receive ADS-B off aircraft off the East coast of Southern Ireland!

Pretty good for a small helical antenna considering I'm on the ground 

[Russ_H]

Trapdoor, that looks very neat.
Do you have a link for an adaptor for the SMA connector, I don't what the connector type on the dongle itself is called, otherwise I would google for one.

cheers, Russ

Doh, just re - read RG's post, (should've gone to specsavers) .......so its an MCX connector

[neilmurg]

could I have an ebay ref for the right connector? is it:
http://www.ebay.co.uk/itm/BNC-Female-Jack-To-MCX-Male-Right-Angle-Pigtail-Adapter-Cable-Connector-RG316-/291504348014?hash=item43df035b6e

thanks in anticipation

[Bill Maxwell]

I don't think it is the correct adapter, although I'm not sure which post you are referring to. BNC is a very different connector to a SMA.

[ianfallon]

I get decent range from the std antenna that came with the cheap dongle (ie I can see Luton arrivals from Oxfordshire with it on the ground in the garden here). It doesn't need mega range.

[Bill Maxwell]

Luton to Oxfordshire doesn't mean much to me this far away, Ian. What sort of distances are we talking of?

Bill

[ianfallon]

80 miles ?! Actually the best I think I have seen with it (not even in the air) is about 100 miles.

More questionable is the ARF range but not tested that air-air yet.

[trapdoor]

My air test on Tuesday proved that my ADS-B antenna did what it was supposed to.

As for being hung up about the range you are getting ... Why do you NEED 100nm range in the air? It's just far more data for both the PA box and SD to process and send over the WiFi link, much more than you are ever likely to want to see on your SD map at the usual zoom levels we all fly with. If anything, it could be sensible for the software to turn down the gain on the DVB-T dongle to actually reduce the range.

As for the P3i tests ... I have been in communication with Lee about this and he has posted about possible issues with the way the P3i antenna is connected to the ARF. My own testing showed that range was certainly way less than optimal after running several passes towards and over my ground station. My aircraft is an all-metal EASA type which limits what I can do with antennae so my tests were run with the supplied ARF antennae with the airborne PA box velcro'd on my glareshield.

When I get some free time next week I will be modifying my ARF's with end launch SMA's to see if that improves matters.

The more air tests that can be done the better but the results need to be qualified as to what type and construction of aircraft it was tested in as this could have a bearing ... Mine is probably worst case but typical for PA28 type all metal aircraft - someone with say a Sportscruiser or Europa etc may get significantly better results with the same setup I employed.

[Bill Maxwell]

I'm sure we don't want 100 mile range. My immediate concern would be traffic within 10-20 miles. I would be very worried if my system was deaf to traffic at say 5 miles range and worried wouldn't even start to adequately describe my concern if the range was significantly less than that.

[trapdoor]

I'm sure we don't want 100 mile range. My immediate concern would be traffic within 10-20 miles. I would be very worried if my system was deaf to traffic at say 5 miles range and worried wouldn't even start to adequately describe my concern if the range was significantly less than that.

With a properly tuned 1/4 wave antenna, from south of Bristol I can 'see' traffic to the North of Liverpool (easterly traffic is blocked from me due terrain) and way over to S. Ireland. The 3G Siretta antenna I have elected to use reduces this range to 50 odd miles, perhaps a bit more but as far as I'm concerned I'm quite happy with this.

Doing my flight test on Tuesday was interesting. Climbing out of Kemble we were 'warned' about an inbound BAe146 on a very long final to 08 - an absolute doddle to spot on the ADS-B due to knowing its flight number (s/w I was running gives flight number and not ICAO hex) so we could keep out of it's way - even though we passed closer, same level, than I have ever flown to a CAT before. Whilst running the tests to my ground station we were working Bristol Radar but under their CAS and were able to identify traffic in and outbound to both Bristol and Cardiff and well within the normal map scaling on SkyDemon. It hugely improved situational awareness.

However, this is the reason why I believe we need to see more than the ICAO hex on the display because it's pretty meaningless. Flight/Reg numbers here make positive ID when under a service a doddle.

[neilmurg]

I went for a 95 - 1100 mhz antenna https://www.sinotel.co.uk/index.php?main_page=product_info&cPath=14&products_id=141 on the dvb dongle.

This adapter? http://www.ebay.co.uk/itm/MCX-male-plug-to-SMA-female-jack-bulkhead-nut-for-pigtail-cable-RG316-15cm-/380415471408?hash=item5892876f30