Using 2 SDR's - Weather ...

[Seanhump]

Quick one ..

When using 2 SDR's to get 978 Weather broadcasts, do they NEED to be the same, or can different makes / models be used ..?

Individually, each of the ADSB dongles I have work fine with my setup (Pi3, 20180520 Software) - they are

The 'stock' one that comes with PAW
A Nooelec Nano 3
A RTL Low Power V2 SDR

Mixing them up seems to make one drop off line - sometimes the first one (ie, the one used for ADSB), sometimes the second one (the weather one). Which ever one is left seems to then revert to ADSB duties - I've had the 'second' weather one picking up ADSB signals with the tuned 978 Antenna when the 'first'  one dropped offline...

I've moved them around to different USB ports with no change (power cycles etc whilst swapping / moving around)

The only config I've NOT tried yet is two of the same type (I didn't take the second Low Power RTL Dongle with me unfortunately!!)

Just thought I'd check so I can diagnose further before heading down south in a week or so's time for a job  (where I'll see how the weather stuff works)

Apologies if this has been answered and I've missed something ...

[exfirepro]

Hi Sean,

Paul Sengupta has tried various dongles. I know he has had results with 2 x standard ‘Realtek’ ones, though they definitely get hot, but not sure if he has used Realtek in ‘combination’ with the low-power ones. I have only tried it with 2 x low power ones and only on the one trip down south back in May, with I would have to say produced fairly unimpressive results. Looking forward to having another go when I come down for the LAA Rally (if the Wx plays ball). I will be interested to hear how you get on.

Best Regards

Peter

[Paul_Sengupta]

I don't have any low power dongles. I've only tried it with the standard ones. I have some others I could try it with, but they're not the small ones and I'd have to play around with leads and things.

[Admin]

We are recommended the low power v2 dongles.
in order to maintain the power budget

Thx
Lee

[Seanhump]

We are recommended the low power v2 dongles.
in order to maintain the power budget

Thx
Lee

Thanks Lee

Makes sense, though I did check the Home screen via the browser, and there was no throttling (0x0) - one of the first things I thought of...

Will report back with both Low Power V2 dongles ..

Cheers

[Seanhump]

.. just a quick update ...

2 low power dongles have been in use for around 30 hours in the air with no hiccups to report..

It looks like PAW prefers 2 dongles of the same type, and that they’re the low power ones ...

I’ve not ventured far enough to the south to pickup the UAT weather signals yet, but due down there shortly .. will report back when I pick some up ..

Interestingly, lots of ground stations picked up over the weekend around Blackpool and the Lake District whilst out and about..

[exfirepro]

Hi Sean,

Thanks for the update. I’m still a bit sceptical about the effectiveness of the limited trial sites and the usefulness of ‘Rain Radar’ in the UK in general, but could really have done with decent in-air Wx bulletins yesterday (Monday), trying to head home from Sywell after the LAA Rally.

I was just about to leave Sywell after packing up all my gear and checking Wx locally, intending to head for the Manchester Corridor and hoping to try to get behind the front and up the West Coast, when another pilot showed me the latest ‘Rain Radar’ on his smartphone. Now showing heavy rain over the Lakes and all the way south except for a narrow ‘gap’ into Mid Wales. OK - quick change of plan and headed south west towards the ‘gap’. Clear and sunny with broken cloud at c.4-6000ft as I passed Wellesbourne and around Gloucester, with blue sky above and I could see right down the Severn. I considered going above, but could see less ‘gaps’ to the West, so decided to stay below,  but as I turned northwest, my ‘gap’ vanished rapidly as I approached Shobdon and heard a heli - presumably just ahead of me but not showing on PAW - tell Shobdon he was ‘abandoning and returning to Gloucester’ about 3 miles out of Shobdon as ‘Cloudbase’ was down to 300ft - after asking for and having received an ‘advisory’ report from Shobdon minutes earlier that rain there had stopped and that cloud locally was ‘broken at about 800ft’.

I tried going back East, then North but was met with another wall of cloud, so decided to put down at Pound Green in descending cloud and 20g30kts as the front approached. My only other viable alternative after almost 2 hours in the air was back east towards Birmingham and Sywell. I received a call shortly after landing from a fixed wing colleague grounded at Beverley after trying to get north via the East Coast, so no better there.

Unfortunately as you know, ‘Rain Radar’ doesn’t give the full picture. The ‘rain’ when it appeared at Pound Green actually consisted of about 10 - 15 minutes of light drizzle, which barely wet the plane, or me tying it down for the night as by the time the CLOUDBASE lifted again, it was too late to go on and still 10G20kts, so still here. Hospitality 1st Class though - the owner made VERY welcome despite no PPR.

I will now watch the weather developments with renewed interest. 

Best Regards

Peter

[Ian Melville]

I'm also in half minds about the wax trial. On a PAW it seems to lack any meaningful range at High Wycombe with broken data streams. Have been unable to test in the air properly due to lack of an aircraft . Milbourne Port data stream seems good, but you cannot get far away and be in line of sight while on the ground, so no idea of range yet. I wanted to compare with SkyEcho, but the only owner I know is prone to exaggeration

I practice I found that radar does not show light rain. It also is not an indicator of cloud, so 'gaps' may actually be solid on the deck cloud. Better than nothing if you are touring.

[Seanhump]

I'm heading off to Milton Keynes tomorrow, which, according to the Uavoinix info, should put me in range of one of the test stations (assuming I'm around 2-3000')

I figure that it's going to be handy, but not a deal breaker by any stretch - the Mode S visibility that's being worked on is way more useful. (I wonder if that will still work with GLD90 ..??)

Weather, as always, is a major factor, especially in this country as things change pretty quickly - the last flight on Sunday had to be amended 'on-the-fly' due to the rapid change in cloud cover over Windermere. Anything that helps is always a bonus, but in the rotary world where we're low and slow, you can always pop it down in a field if things go pear-shaped quickly...

[Paul_Sengupta]

Rainfall radar is very useful is showing where you shoudn't fly. It's less of an indicator of where you should fly, as mentioned. Looking at the rainfall radar for yesterday, I think I'd have spent another night at Sywell!  Funnily enough, I was on my way back from Scotland once and there was a huge front almost from Newcastle all the way across the country down through Cornwall. It was moving along its length, travelling towards Newcastle. On the ground in Carlisle, I could see that Newcastle was in the clear...but the front was approaching. Rather than travel south, I headed east to the coast around the end of the front and down. As I headed south from there into the clear skies beyond, I could look back inland and see the blackness underneath the front, and on the radio I heard airliners diverting...