HamTV Status

S-Band DVB-S from the International Space Station
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HamTV Status

Post by G8GKQ » Fri May 03, 2024 6:41 pm

This topic will be updated with the latest status of the HamTV equipment on the ISS. As of 2 May, the latest update fron the ARISS team is:

ARISS is looking forward to having HamTV being fully operational as early as first part of June on ISS. Current plan is for the unpacking and installation of HamTV by NASA astronauts at the earliest on May 22nd!

Get ready to start receiving DVB-S pictures from ISS on 2.395 GHz.
https://wiki.batc.org.uk/HAMTV_from_the_ISS

Note: May 22nd date is dependent upon astronauts workloads on ISS i.e. may slip a few days/week….stay tuned latest update


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Re: HamTV Status

Post by n3cxp » Sat May 25, 2024 3:00 pm

HI, I'm wondering what the thoughts are about decoding the ISS DTV using some old technology. I've recommissioned both a sub-2dB Drake and DEM2400-144RX down convertors, in addition to a 13ULNA with a 0.7 dB noise figure. I have a 3' dish with AMSAT RHC patch feed that was manufactured for AO 40. Have the hardware on the cross boom, and SDR Angel configured for DVB-s. I can see WIFI Channel 1 and 6 with the Drake, which is more broad banded than the DEM, and am a bit concerned about that blanking out the downconverters without a low-pass filter.

Thoughts on using this older technology vs. the MiniTiouner V2? I'm unfamiliar with using a Rasberry PI and was hoping the down conversion to 144 MHz would still be viable.

Tom Daniels
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Re: HamTV Status

Post by G8IKP » Sat May 25, 2024 4:44 pm

I dont think you can use a minitiouer under 144Mhz. To receive 2395 Mhz on an old AO40 converter you would need to tune to 139Mhz that's not within the spec. of the tuner used in the Minitiouner or PicoTuner receivers.

John G8IKP
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Re: HamTV Status

Post by g8lce » Sun May 26, 2024 7:33 am

You could use an upconverter with a 125MHz uplift to the frequency. Very cheap from China!

Martin G8LCE

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Re: HamTV Status

Post by G8IKP » Sun May 26, 2024 7:44 am

You could also change the xtal in the LO of the converter and realign for a 432Mhz IF ? That converter was made in two IF versions.
John G8IKP

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Re: HamTV Status

Post by n3cxp » Sun May 26, 2024 12:41 pm

Thanks Martin and John!

I wasn't clear with all my ramblings. My system is pretty well complete with the Drake 2880 down convertor translating signals to 2M. I'm using an RSP DX SDR as my IF receiver on 2M. Both down convertors are seeing signals in the 2.400+/- (mostly WiFI on CH1 or CH6) and will easily go down to quite a bit below the 2.395 Mhz downlink. I remounted the dish on the existing sat cross boom, so all good in the tracking department.

My question is whether the Minitouner based system will have any advantage in decoding DVB-S vs the SDR Angel/ current old school down conversion scheme? I've configured SDR Angel with the correct parameters and bandwidth, but am waiting to see the pilot carrier from the Ham TV equipment.

Tom
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Re: HamTV Status

Post by G8GKQ » Sun May 26, 2024 8:18 pm

Hi Tom

There seem to be 2 issues here.

The first is whether there would be an advantage to using a MiniTiouner based solution over SDR Angel. The answer is a resounding yes. MiniTiouner achieves symbol lock a lot faster than SDR Angel, and also needs less signal to noise ratio to achieve the lock. Estimates of the difference beteween the 2 for DVB-S vary between 2dB and 5 dB. MiniTiouner based solutions are also a lot less fiddly to set up. I would recommend OpenTuner software on a PC (rather than F6DZP's MiniTioune) or Ryde or Porstdown on a Raspberry Pi as the software to use.

The second issue is whether your down-converter will convert 2395 MHz to a suitable IF, as the MiniTiouner's lower frequency limit is 144 MHz. That's one for you to answer.

Dave, G8GKQ

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Re: HamTV Status

Post by n3cxp » Sun May 26, 2024 9:12 pm

Dave,
Thanks for the reply. I’ll dig into OpenTuner software for Windows and see how that plays out.
As far as part 2, the folks at Down East Microwave assure me the DEM 2400 144RX will operate with a good noise figure at 2395 MHz as well as their LNA.
As far as I can tell, I tested both with a small 5mw oscillator and both seemed to have good sensitivity below 2400Mhz.

Before I invest time in one of the MiniTiouner solutions, I figured I’d make sure the HamTV experiment becomes a reality. Shame we lost interest and resources stateside in Mode S and beyond.
Tom

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Re: HamTV Status

Post by Phil M0DNY » Mon Jul 01, 2024 9:01 pm

After delay due to space-congestion in the Columbus module, we're now expecting the HamTV system to be powered on around the end of July.

This is still dependent on some paperwork related to the new installation that ARISS is working on with NASA.

Phil M0DNY

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Re: HamTV Status

Post by Phil M0DNY » Wed Jul 10, 2024 10:22 pm

We're hearing there's further delay in the installation due to the congestion of space in the Columbus module, end of July is no longer realistic.

"Space is big, really big." - Just not when you're cramming equipment into a 25-year-old research station.

Phil M0DNY

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