Portsdown to Fly on HAB High Altitude Balloon

Discussion about this major DATV Project. See also https://wiki.batc.org.uk/The_Portsdown_Transmitter
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K5SAF
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Joined: Sat Aug 24, 2019 5:02 pm

Portsdown to Fly on HAB High Altitude Balloon

Post by K5SAF » Sat Aug 24, 2019 5:27 pm

The South Texas Balloon Launch Team - BLT will fly Portsdown 2019 on a flight from the Houston, Texas area on September 28. The balloon typically reaches 100K feet altitude, 50 mile max ground track & 2 hour duration. The frequency will be 1280 MHZ. The package rotates and swings quite a bit and is almost constantly in motion. We would like have 720P resolution if possible and have both PiCam V2.1 and C920 cameras and Pi 3B+ units. We will be using MiniTiouner-Express receivers. I have had issues during testing and will post details separately.

Suggestions from the group on the best combination of modes and parameters to deal primarily with constant motion are greatly appreciated.

Thanks for the bandwidth & 73,
Tom K5SAF

G8GKQ
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Re: Portsdown to Fly on HAB High Altitude Balloon

Post by G8GKQ » Tue Aug 27, 2019 8:41 pm

Hi Tom

Will this use a LimeSDR or a Portsdown F-M board?

I would suggest using the PiCam rather than the C920 if using LimeSDR.

Dave, G8GKQ

f1faq
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Joined: Thu May 12, 2016 1:19 pm

Re: Portsdown to Fly on HAB High Altitude Balloon

Post by f1faq » Wed Aug 28, 2019 4:12 pm

Hello,

Have a look at this video : https://www.youtube.com/watch?v=sPvHUBGsxK0
Launch of the balloon starts at 2:30:00
Done with Raspberry Pi + PICAM + DVBSDR software from F5OEO (included in Portsdown also) + PA 2W
Contact if needed : f4cqa@free.fr

73 - Christian
F1FAQ
73's - Christian
F1FAQ

K5SAF
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Re: Portsdown to Fly on HAB High Altitude Balloon

Post by K5SAF » Wed Sep 04, 2019 9:03 pm

Thanks Dave & Christian for your responses - sorry to be slow but I've been away.

I'm using a LimeSDR Mini for the xmtr fed by a powered USB hub - I have 2 and both produce the same results.
Christian, fantastic video from your flight - I commented on YouTube. I will also reach out to you directly.

I am struggling with different symptoms almost every time I try to test a combination of cameras & resolutions. My goal is 720P with good motion tolerance.
I have 2 Pi 3 B+ each running Portsdown 201907272. One has a Pi Cam v2.1 connected and the other has the C920 by USB.
I have 2 MiniTiouner-Express rcvrs and run MiniTioune v0.8 software and I see the same results on both rcvrs.

The basic result is the same for Pi Cam source at any resolution using MPEG2 for example - most of the time but not always the rcvr can not 'lock' on the signal for more than a few seconds - sometimes longer. With the C920 sourced as 'Webcam' sometimes the C920 led comes on for about 2 seconds only and no signal seems to be transmitted from the Lime. At other times the rcvr will 'lock' on the signal for a few 10-20 seconds before it's lost. I have tried the C920 @ H264 720P and have latency and major pixelation which would not be usable for the flight.

I'm trying not to overload you or the board and I'd be happy to share short video or stills if that is useful or put them up on Dropbox with links.
Please give me some direction.

73,
Tom K5SAF

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