PS-43 PICO balloon HF payload WSPR JT9

[VK3YT]

Hi all,

FYI,

PS-43 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.

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

Tracking as PS-43 on SNUS http://picospace.net/tracker/new
WSPR call sign is VK3ANH http://wsprnet.org/olddb?findcall=vk3anh

Prediction


Andy

[VK4ADC]

Interestingly, the WSPR ID is VK3ANH but the JT9 ID is VK3YT

From WSJT-X:

0002 5 -0.3 1005 @ VK3YT49A3SVM9
0022 3 -0.2 1005 @ VK3YT4993TW8B
0023 1 -0.2 1005 @ 23-O24805LQ0H
0042 0 -0.3 1005 @ VK3YT4A93TWKA
0043 2 -0.3 1004 @ 23-J24DE5JL19
0102 2 -0.6 1004 @ VK3YT4993SX0A
0103 5 -0.5 1004 @ 23-O24J05KM20
0122 4 -0.5 1004 @ VK3YT4973SXS8
0123 3 -0.4 1004 @ 23-O24OM5FU2U
0142 5 -0.3 1004 @ VK3YT4983QY6C
0143 0 -0.2 1004 @ 23-C24TY5WX3J

From WSPR-X :

0128 -26 -0.8 10.140183 0 VK4GO QH22 23
0130 2 -0.6 10.140204 -1 VK2KYP QF56 23
0130 -17 -0.6 10.140242 -1 VK2GOM QF56 23
0132 -27 -0.8 10.140183 0 VK4GO QH22 23
0136 -24 -0.7 10.140183 0 VK4GO QH22 23
0140 1 -1.3 10.140111 0 VK3ANH QG85 10 **************
0140 -22 -0.7 10.140183 0 VK4GO QH22 23
0140 2 -0.7 10.140202 0 VK2KYP QF56 23
0140 -11 -0.7 10.140242 0 VK2GOM QF56 23
0144 -24 -0.7 10.140182 0 VK4GO QH22 23
0148 -26 -0.8 10.140182 0 VK4GO QH22 23
0150 0 -0.8 10.140201 -1 VK2KYP QF56 23
0150 -16 -0.8 10.140241 -1 VK2GOM QF56 23

It is so easy to run both programs on the same PC, with one audio source, to do the decodes. Dual screens help too.

[VK4KL]

Doug
I have dual screens on my pc but cannot get both wspr or wsjt to run at the same time, its either one or the other.
How did you manage?

Adrian

[VK4ADC]

Doug
I have dual screens on my pc but cannot get both wspr or wsjt to run at the same time, its either one or the other.
How did you manage?

Adrian

I am currently running WSJT-X v1.5.0-devel and WSPR-X v0.8 r3058 but when I tried some earlier versions of the WSJT code, I couldn't get them to run similtaneously either. Sound card access conflicts were happening - but not with the versions noted above.

[VK4ADC]

Hi all,

FYI,

PS-43 is in the air.

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

Andy,
if it isn't too much extra effort, could you include the band-switching schedule with each new flight. I found that I was listening on 20m instead of 30m at specific 10 minute intervals, not hearing the HAB and getting disgruntled. A quick inclusion in the "paste" body - along with the other things obviously "pasted" would make it less confusing.

Thanks
Doug

[VK3YT]

Andy,
if it isn't too much extra effort, could you include the band-switching schedule with each new flight. I found that I was listening on 20m instead of 30m at specific 10 minute intervals, not hearing the HAB and getting disgruntled. A quick inclusion in the "paste" body - along with the other things obviously "pasted" would make it less confusing.

Thanks
Doug

Sure Doug, I did forget about new trackers
Used to get listed with slight changes but they are pretty much fixed now:

0 30m // Mandatory JT9 and WSPR, two per hour
10 20m // Optional JT9/JT65 and WSPR – unless batt low
20 30m // Optional JT9/JT65 and WSPR – unless batt low
30 20m // Mandatory JT9/JT65 and WSPR, two per hour
40 30m // optional JT9/JT65 and WSPR – unless batt low
50 20m // Optional JT9/JT65 and WSPR – unless batt low

Thanks for tracking!

Andy

[VK2XTC]

Sorry if this is a real newby question.

I have WSJT-X running to monitor JT65 and JT9.
At the same time I have WSPR-X running with WSPR-2.

Both apps are running at the same time listening to the same Signalink. I can see WSPR-2 signals on WSJT etc. (won't decode of course)

Are you saying that at the 30 minute interval it will transmit JT9 and JT65 and WSPR-2 on 20 Meters?

Is that how I read that last post ?



Brian

[VK4ADC]

Brian

I read elsewhere that it is not advisable to set it to JT9+JT65 when looking at HABs unless the "flyer" specifically states that setup. I am using WSJT-X v1.5.0-devel (JT9 mode) and WSPR-X v0.8 r3058 (WSPR-2 mode) and both are decoding from the one audio source into the same sound card port.

From Andy's list, yes the HAB will tx on 20 metres at the half hour eg 1030, 1130... and 30 metres on the hour.

The battery seems to be dropping fast (3.348V) but it may wake up tomorrow once the sun gets on the solar panel and then it will transmit every 10 minutes on either band according to table above.

[ZL1RS]

This might be clearer:

The bands and modes change according to the following schedule:
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

Full battery = >4.0V.

Frequencies:
30m - standard WSPR dial frequency 10.138.7 with the PS-43 JT9 telemetry appearing at about 1000Hz on the WSJT-X waterfall
20m - standard WSPR dial frequency 14.095.6 with the PS-43 JT9 telemetry appearing at about 1000Hz on the WSJT-X waterfall

You need to set WSJT-X mode to JT9 only otherwise the software will be looking for JT9 signals higher in the audio spectrum and won't decode PS-43.

At the present time PS-43 has been in darkness for some hours and only the 'mandatory' sequences are being transmitted. Secondly, it is damn cold at 9500 meters ASL at night and the battery can 'freeze' thus shutting down the transmitter.

Good luck and 73,

[VK4ADC]

Bob, Brian

I am surprised the Tx is still up at -47.5 celsius according to this latest info - 0900Z. Batt is 3.264 so on its way down for the night now.

The whole transmission sequence takes 4 minutes and you need to make sure your PC clock is synchronised to a good time source.

The tone from PS-43 is 1000 Hz+/- 1 to 2 Hz on JT9 and 1410 Hz +/- 5 Hz on WSPR accoring to my observations over the last couple of days. That assumes that your HF transceiver is accurately netted to frequency too.

[VK2XTC]

Thanks for the answers.

So there is no JT65 then , only WSPR and JT9 ?

Key point to turn it to JT9 only in order to get it to decode below 2500. Didn't see that in any docs !! Thanks

Doug,

Didn't understand the comment about " not advisable to set it to JT9+JT65 when looking at HABs unless the "flyer" specifically states that setup " . Not sure why that would be.
Anyway, comment from Bob seems to clear up the question of JT65.

One step closer !

Brian

[ZL1RS]

Hi Brian,

JT65 is not used anymore, only JT9 (until something more sensitive comes along!). JT65 was trialled after Olivia 8/250 was used initially (with poor success), but the wide bandwidth of JT65 meant it was more susceptible to QRM, so it was replaced with the much narrower bandwidth JT9 scheme which has proven quite good so far.

I think the WSJT-X "JT65 + JT9" mode looks for JT9 above 2500Hz, but it might be above 2000Hz?? It is in the documentation somewhere ...

73,

[ZL1RS]

... it is worth noting that the battery voltage displayed from the telemetry is the instantaneous 'loaded' voltage at the time of the transmission, but the controller makes the decisions on the 'unloaded' battery voltage while not transmitting, so there will be a discrepancy between the action taken at "Full battery = >4.0V" noted in the table above and the voltage shown in the telemetry as displayed on Habhub.

Also, the internal resistance of the battery increases significantly at lower temperatures, so the 'unloaded' to 'loaded' voltage discrepancy will be larger at night. This becomes particularly apparent if the balloon bursts at night and the temperature increases as the altitude gets lower during the (approx.) 2 hours it takes to fall ... the battery voltage rises even though there is no solar charge!

BTW, two instances of WSJT-X v1.5.0-dev and two instances of WSPR-X running here on one computer being fed by two radios, one for 30m and another for 20m, and a selection of broadband directional antennas to choose from according to the position of the balloon. Some clever people have managed to get one radio to frequency hop to the schedule as required via CAT control

The challenge I enjoy is messing with antennas to get consistent JT9 telemetry decodes from the 25mW transmitter from as far away as possible.

73,

[VK4ADC]

Bob

Have you put a big RF magnet in place ??
It looks like it is heading directly towards you

I am starting to think that I could plot my dipole's polar pattern from the signal levels reported - well, the eastern lobe anyway.

[ZL1RS]

Doug, we have a standing joke with Andy that the balloons are attracted to my "cows"

There must be something in the upper atmosphere wind patterns because several flights that have followed roughly the track that PS-43 has taken have passed within a few hundred km of here. Those that fly SE from VK3 when launched and cross over/near VK7 tend to continue well south of ZL and get to South America quite quickly (if they survive).

73,

[VK3KCX]

Another balloon in the area http://www.csbf.nasa.gov/map/balloon9/Google662NT.htm

[ZL1RS]

A little bit of excitement over night ...



Note the 'SOS' schedule kicked in as PS-43 fell below 5000m. The time frequency of the telemetry transmissions stepped up from the previous 'reduced' night time schedule of one every 30 minutes (subject to a decode being actually received), to about two every 10 minutes.

What was the cause? Rain? Ice? ... either way it made a recovery and continues east towards South America.

73,

[VK3YT]

Hi,
PS-43 descended into the South Pacific this evening, about 3200km from South America

Thanks everyone for assistance with tracking.
See you at the next trip!
Andy