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Right. But what is that in terms of what normally gets described? For example, I have a Digital TV card for my computer (Pinnacle PCTV HD). It says it does "ATSC digital TV (HDTV up to 1080i, and SDTV)" and "Clear QAM (unencrypted digital cable)".
Am I even close?
Greg KO6TH
No, you are not even close.
ATSC (Advanced Television Systems Committee) is the proprietary over-the-air television broadcast standard used in North America. It is fundamentally incompatible with the open source "DVB-T" broadcast standard that the rest of the world uses for domestic TV. (The fact that it was designed by a committee should tell you all that you need to know about that particular political sausage.) The "Cheap and Easy SDR" article in January QST requires using a DVB-T USB dongle which you need to purchase from a supplier that knows that you want to use it for SDR. The ATSC USB devices sold at Best Buy or other retail stores in the USA cannot be used for this purpose.
QAM is used only by cable TV and is never broadcast over the air. (Most cable systems use encrypted QAM so you will still need to rent the decoder box from the cable company).
DVB-S is the digital satellite TV standard that the "free to air" (FTA) satellite receivers use. We are not talking about Direct TV or Dish TV, but the C band services. If you watch NASA TV or the foreign language TV broadcasts directly from your C band dish, you are using DVB-S. This standard has been used for terrestrial ham ATV in some US cities. It would be best to contact the ATV experts directly to see what receivers they are using. I don't know which FTA receivers will work with the ISS ham TV.
Bottom line is: ATSC and QAM decoders are not useful for receiving the ISS ham TV signals, and DVB-S is not widely used in the USA except by dedicated "free to air" hobbyists. If you bought your receiver card or dongle from any US consumer retail store, it almost certainly is not what you need for ISS ham TV.
Dan Schultz N8FGV
Typo on my earlier email I meant HTV-4 not ATV-4 and so launch date is different around August ?
ARISS Antennas Installed on Columbus http://www.ariss-eu.org/columbus.htm
73 Trevor M5AKA
Thanks, Dan. That helps a lot. Is there something about the DVB-S modulation that makes it astoundingly better for this application? For something that is intended to be widely received, they sure are making it difficult... Greg. KO6TH
--- On Mon, 13/5/13, Greg Dolkas ko6th.greg@gmail.com wrote:
Is there something about the DVB-S modulation that makes it astoundingly better for this application? For something that is intended to be widely received, they sure are making it difficult...
DVB-S receivers are in use in hundreds of millions of homes around the world. Apart from DVB-S2, which is not yet so widespread, I'm not aware of any other standard that would deliver better performance in a 2 MHz bandwidth.
73 Trevor M5AKA
2 mhz? Yeah, that would be tough... Ok, DVB-S it is.
Thanks all for the education. There's a swap meet coming up in a couple of weeks... Sounds like I have a now have a mission. :-)
Greg KO6TH
M5AKA wrote:
--- On Mon, 13/5/13, Greg Dolkasko6th.greg@gmail.com wrote:
Is there something about the DVB-S modulation that makes it astoundingly better for this application? For something that is intended to be widely received, they sure are making it difficult...
DVB-S receivers are in use in hundreds of millions of homes around the world. Apart from DVB-S2, which is not yet so widespread, I'm not aware of any other standard that would deliver better performance in a 2 MHz bandwidth.
73 Trevor M5AKA
participants (4)
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Daniel Schultz -
Greg D -
Greg Dolkas
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M5AKA