PS-46 PICO balloon HF payload WSPR JT9

[VK3YT]

Hi all,

FYI,

PS-46 is in the air.

Solar powered party balloon, 25mW TX
TX WSPR, JT9 on 30m and 20m

Dial frequency 10.138700Mhz and 14.095600Mhz (standard WSPR dial frequencies) for WSPR, JT9.
JT9 is at 1800Hz

See HF decoding info at http://picospace.net/?cat=34

Tracking as PS-46 on SNUS http://picospace.net/tracker/new
WSPR call sign is VK3YT http://wsprnet.org/olddb?findcall=vk3yt

TX scheduling
Minute - Band - Mode - Condition
:00 - 30m - 2 mins WSPR then two x 1 min JT9 - mandatory
:10 - 20m - 2 mins WSPR then two x 1 min JT9 - if batt full
:20 - 30m - 2 mins WSPR then two x 1 min JT9 - if batt full
:30 - 20m - 2 mins WSPR then two x 1 min JT9 - mandatory
:40 - 30m - 2 mins WSPR then two x 1 min JT9 - if batt full
:50 - 20m - 2 mins WSPR then two x 1 min JT9 - if batt full

Prediction:


Regards,
Andy

[VK2PR]

YAY! Just got my first ever decode of one of your balloons Andy. 30m WSPR and JT9.

[VK2XTC]

At last my first JT9 decode from a balloon !

1032 -27 0.5 1821 @ VK3YT17536O?0

I don't have the plug in to WSJT-X so I cannot upload it. (I'm running on a Mac)


Brian

VK2XTC

[VK2XTC]

Here's what I get.


1202 -19 0.4 1816 @ VK3YT18936O?0

1203 -18 0.1 1816 @ 1/ 721I 4?MB.

So, now the the next challange , what do I do with the data ?


Brian
VK2XTC

[VK3YT]

Nice work guys
It's been a while since a PS balloon was that close to Sydney.

Brian, I use Fusion to run WSJTX in windows on my Mac.
Will see if we can compile a version for Mac soon.

Andy

[VK2XTC]

Andy,

I'll just have to tell the wife I need a new PC.
The Mac was a choice for Family PC, very young kids just click away, plus it works well with Phones and iPads, and all the Family Photos etc.
Did a deal with a mate and got it cheap. Could always make it dual boot if required.


Speaking of Photos, we are really in need of some pictures. The balloon, the Transmitter etc.
How are you getting it all packed into one little unit ?


Brian

[VK3DXE]

Great to see PS-46 still aloft and halfway across the Southern Ocean on its way back to Australia tonight.

[VK3YT]

PS-46 is expected to cross the starting longitude of 144.894 at 06:00 4/6/2015 UTC, completing the circumnavigation around the Southern Hemisphere.

[VK5EI]

Welcome home PS-46 Well done Andy, propagation has been challenging on this flight. Noticed the balloon entered into some fast winds and approached us very quick.

Dashboard view

[VK5RM]

Yes well done Andy, lots of stations up and tracking.
I wonder if we will see a 2nd circumnavigation?

Phil VK5RM

[VK3YT]

Hi all,

PS-46 crossed the starting line yesterday and kept on going. It crossed the international dateline today, the second time.



Prediction



Thanks everyone for assistance with tracking, and let's see how much further PS-46 will get to

Andy

[VK2DX]

Hi Andy -
last decode on 30m ->9,288 km

2015-06-08 09:00 VK3YT 10.140266 -22 3 DG54 0.01 VK2DX QF56oe 9288 235
73 Nick VK2DX
Sydney

[VK2XSO]

Just checked up on it again, back over the South Atlantic Ocean again.

[VK5RM]

PS-46 is on its way home again and all winds pushing it to VK.

The latest position is in the South Atlantic and was last logged by ZS6BTY

Phil vk5rm

[ZL1RS]

Oh how things can change in 24 hours! According to the reality of the present situation (only a few hundred km traveled since yesterday and the present speed of 21km/hr) and the latest Hysplit 'model' from NOAA now shows 4 or 5 days doing loop-the-loops in the Atlantic Ocean before moving slowly across Southern Africa ...

[VK5RM]

Yeh amazing Bob ,this is another perspective but I just hope it stays up awhile yet.

Also Bob you have a great system working there to capture data from the bird and always the first and last to see it in Oceania.

[ZL1RS]

FB Phil, I ran a couple of predictions at different heights (only 100m different) and the results were quite different. PS-46 will do what it will do

I did a lot of playing with antennas to receive the HF telemetry from these 25mW PS balloons over the last year. As you noticed, the present system is working pretty well ... and it could not be simpler! After reading various 'receiving antenna' information, I finally realised that RDF (Receive Directivity Factor) was the important key to improve SNR on weak signals. As noted in W8JI's Internet pages, one of the better antennas for receiving is the Beverage ... it is well tried and proven on the low bands. Fortunately a Beverage on the 30m and 20m bands only needs be 60m long (2 WL at 30m and 3WL at 20m ... not critical) and there is room on our small holding to run wires that far in the various paddocks around the house. On the 30m and 20m bands the Beverage wire height only needs be about 70cm above the ground (also not critical), so I am using 'portable electric fence standards/pigtails' to support the Beverage wire. As a result the Beverage direction can be moved in about 5 minutes (a move is usually only required once a day). There is a W7IUV preamp at the Beverage feedpoint with a 9:1 transformer wound on a little binocular core to roughly match the Beverage feed impedance to the low input impedance of the W7IUV preamp.

Of course the rural location comes with zero man-made noise which helps a bit too

73,

[VK5EI]

I agree with you Phil, Bob has one of the best ears down south

PS-46 is testing our ability to receive weak signals using our antenna systems during these propagation conditions, antenna gain becomes paramount.

The earth wind map attached is wind speeds at 10hPa, if PS-46 moved more south it should pick some speed and come our way quicker

73

[ZL1RS]

... PS-46 is testing our ability to receive weak signals using our antenna systems during these propagation conditions, antenna gain becomes paramount

For receiving on HF (particularly the lower bands like 30m) it is not so much gain, but an improvement in Signal to Noise that gives a better result. This largely comes from the radiation pattern or 'directivity' of the antenna suppressing noise from unwanted directions. To get a grip on the concept, Google 'receive directivity factor' and read the search results written by low band DXers. I read them after I had 'discovered' for myself that the Beverage antenna was the best of what I had tried for receiving the weak signal from the PS-series balloons. A close second was a 4 element wire colinear (Lazy-H) supported on two 18mH masts, but the 60m long Beverage at 70cm above the ground is definitely better on receive, much easier to implement, and easier to change directions!

Owners of stacked Yagi arrays on 30m and 20m would probably do better again ... not because of the dB gain of these systems (which is essential for a big transmitted signal), but due to the narrower radiation pattern from the stacked array reducing noise from unwanted directions.

John VK2FAK with space limitations on his urban property (he doesn't even have room for a 20m dipole) has been experimenting with smaller antennas. His best results to date have been with a Flag antenna. He scaled the dimensions commonly used for the Flag on 160m and 80m down to the 30m band (not critical) and has more or less doubled the range of reception from the PS-series balloons compared to his previous results with the tuned loop and bent dipole originally used.

73,

[VK2HRX]

Bob, Thanks for the antenna explaination, very helpful. I can now see why I have difficulty with these balloons. Only got room for a 40M loop and 80m bent dipole.