[amsat-bb] Odyssey Siren A success
rwmcgwier at gmail.com
Tue Mar 13 13:35:37 PST 2007
We had a complete breakthrough on the Odyssey Siren in the past two
weeks. It will be used in Suitsat 2, in a terrestrial linear repeater
experiment by Viktor Kudielka OE1VKW and friends, who supported its
development, and we are already leaping all over the place to applications.
Frank Brickle and I will be doing our SDR code on it over the next
several days. The board as shown in the schematic needs some
modifications to fix the 3 - ish volt power supply for the Codec and a
modified oscillator circuit but we are certain it will all work now.
On the 10.7 MHz IF, I measured 0 dBm max into a 50 ohm load and less
than -120 dBm MDS and > 80 dB dynamic range. This is with a BOM of <
$50 in parts and about a $20 dsp pic chip!
Yesterday in Rick's lab, with W2GPS, K3IO, we made the above
measurements, hacked on code and turn the thing into a bent pipe
transponder. I also did the hilbert transform to make it an inverting
transponder. It all worked perfectly.
has detected audio in an SDR-IQ SDR as well as captured IF from the
SDR-IQ of the transponder. We have to balanced for image and do DC
offset correction but the thing works and sounds great as you can hear
AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
"Taking fun as simply fun and earnestness in earnest shows
how thoroughly thou none of the two discernest." - Piet Hine
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