[aprssig] APRN (Automatic Picture Relay Network) revival?

Stephen H. Smith wa8lmf2 at aol.com
Sun Aug 9 17:43:00 CDT 2015


On 8/9/2015 12:07 PM, Eric Grumling via aprssig wrote:
> *http://www.agri-vision.nl/CMS/index.php?option=com_content&view=article&id=54 is
> a Raspberry Pi based SSTV capture and transmission device. With the FM
> transmitter software developed by Oliver Mattos and Oskar Weigl (and
> filtering and likely a bandpass filter it could be a stand-alone transmitter.*
> *
> *
> *73*
> *K0JEG*
> *


Hopelessly underpowered for the intended application.  SSTV is a strong-signal 
mode that needs "full-smash" hard-quieted signals to work decently.  I.e. 
somewhat similar to signal requirements for normal 1200 or 9600 baud packet. 
With the milli-watts range power output of this device, the range will be 
something like Bluetooth or Wi-Fi.  One needs output power on the order of 
watts or 10's of watts to be practical.

Further, the article doesn't indicate what mode(s) this thing transmits.  If 
the intent is to have a large number of igate-like receive installations, they 
will need to run standard modes that can be received by off-the-shelf SSTV apps 
like mmSSTV or HRD DM-780.


I still thing N1VG's SSTV cam board mated to one of his 5-watt FM telemetry 
transmitter modules is the way to go, and far less susceptible to buggy 
software and computer hiccups. One can "hardware" one of several standard SSTV 
formats with DIP switches.


________________________________________________________

--

Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
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