From ARRL:
ARISSat-1/RadioSkaf V will have simultaneous 2-meter FM, CW, BPSK and transponder transmissions. These multiple transmissions are created by a new software-defined transponder (SDX) board. The FM transmissions will cycle between a voice ID, select telemetry values, 24 international greeting messages in 15 languages and live SSTV images. The CW transmissons will be callsign ID, select telemetry, and callsigns of people actively involved with the ARISS program. The BPSK transmissions will feature a new 1kBPSK protocol developed by Phil Karn, KA9Q, to be readable in low signal level conditions. The BPSK data will alternate betwen telemetry and Kursk experiment data. Free groundstation soundcard demodulator and display software will be available before launch for multiple platforms. There also is a 16 kHz wide Mode U/V (UHF uplink - VHF downlink) transponder between the BPSK and FM signals.
From the "Webster" Dictionary (who was Miriam to usurp Noah anyway ?):
tran·spon·der
noun \tran(t)-ˈspän-dər\
Definition of TRANSPONDER
: a radio or radar set that upon receiving a designated signal emits a radio signal of its own and that is used especially for the detection, identification, and location of objects and in satellites for relaying communications signals
Origin of TRANSPONDER
transmitter + responder
First Known Use: circa 1944
From Wisegeek:
A transponder is an electronic device used to wirelessly receive and transmit electrical signals. Fittingly, its name is equally derived from the words "transmitter" and "responder".
From Wikipedia:
In telecommunication, the term transponder (short-for Transmitter-responder and sometimes abbreviated to XPDR[1], XPNDR[2], TPDR[3] or TP[4]) has the following meanings:
- An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator).
- An automatic device that transmits a predetermined message in response to a predefined received signal.
- A receiver-transmitter that will generate a reply signal upon proper electronic interrogation.
There also is a 16 kHz wide Mode U/V (UHF uplink - VHF downlink) transponder between the BPSK and FM signals.
And, the rapidity with which this bird was built is nothing short of disgusting with the anguish that we are put through waiting for a replacement to AO-40 which was used by a government for target practice right before the Chinese openly fired a weapon at a test satellite and destroyed it.
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