Well tonight I was trying a few things on ao-73. But mid pass I got bored if you will and I turned around and grabbed my ft817. I had the mic hooked up and had the stock rubber duck installed already. I dialed in the correct uplink frequency and did I quick test call and sure enough I saw a trace on the water fall. I thought I had it set to five watts but after pass looked and I had it set to 2.5w out. So I heard myself through the transponder using 2.5w into the stock rubber duck on ft817. The link below is a short recording of the audio I got.
https://www.dropbox.com/sh/1ggmarxnx2otjxz/Gjh6imD01t/ft817%20rubber%20duck%...
Anyway it doesn't take much power to work ao73.
73 Wyatt AC0RA
Date: Sun, 8 Dec 2013 15:13:24 -0500 From: n8hm@arrl.net To: amsat-bb@amsat.org Subject: [amsat-bb] Power output for using AO-73 transponder
FYI - In a sidebar on their website, AMSAT-UK requests that stations limit power output to 25W EIRP for using the AO-73's transponder.
"FUNcube-1 / AO-73 Radio Communications Subsystem • 145.935 MHz BPSK Telemetry 30 or 300 mW • Inverting SSB/CW transponder 300 mW PEP
- 435.150 – 435.130 MHz Uplink LSB
- 145.950 – 145.970 MHz Downlink USB
Educational Telemetry beacon is 300 mW during day and 30 mW at night. Transponder is only active during night passes. Please use a maximium uplink power of 5 watts to a 7 dBi gain antenna (25 w EIRP). Lower power will also work well. If adjusting for Doppler shift manually try tuning the uplink frequency while transmitting to keep the downlink constant."
73,
Paul Stoetzer, N8HM Washington, DC _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb