GS says to AMSAT-DL as follows. > I appreciate your offer of 20m dish. > The exact frequency is 5840.000 MHz. > > The RF signal is modulated with FSK of 115.2kbps digital picture data. > Frequency sift is +,- 50kHz, but the spectrum spread over 300kHz. > As we use a simple FSK, FM detector directly generates the signal for > serial-port(RS232C) of PC. The discriminator of FM-radio (IF=10.7MHz) > may be available by removing de-emphasis circuit. > > A jpeg-picture data are sent by packets. Each packet consists > of 128 byte: > > packet-ID data-size picture-data verify > (2 byte) (2 byte) (122 byte) (2 byte) > > Namely, the first 4 bytes and the last 2 bytes do not consist the > photo data. Data-size of all packets except the last is 122(=7A hex). > > A jpeg-picture data starts with "FFD8" and ends with "FFD9". > The jpeg picture is made by connecting the data part of each packet by > removing the first 4 byte and the last 2 byte. > > 20 VGA-pictures are sent at a time. Each picture is sent around 4-6 sec. > There is 8 msec interval between packets. and 5 sec interval between > pictures. > > Please find the block diagrams and circuit schematics in my web-page: > http://www.fit.ac.jp/~tanaka/
October 21, 2012
First picture from NIWAKA by 5.8GHz
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