How to do it… work via satellite with one rig IC-706MKIIG
Do you want to work via a modern amateur radio satellite AO - 40 and you only have one ICOM - 706MKIIG transceiver? It's easier than you think.
The prerequisite is the use of a suitable antenna system . For downlink, for example, dishes with a converter (adjusted to 145 IF) from a digital TV antenna in focus and a suitable antenna for the uplink. To connect the TX antenna and RX converter, it is necessary to use a suitable duplexer on the transceiver side, for example MFJ-916 with a sticker 144/440.
The connectors on the MFJ duplexer should be modified – exchange so, to fit on 706 a rx tx porty, it is also advisable to supplement the connection of the duplexer with the power supply of the converter with crossover via the power coaxial cable . Is possible, that you have some other suitable device with the correct connectors or use adapters according to your needs, if you don't want to modify MFJ.
The secret lies in delaying your own signal back from the satellite. The distance to the satellite and back is roughly 2x 65000 km, which causes a signal delay of about o 0,1 – 0,25 seconds. This time is more than enough for that, to hear your own echo.
Setting up the transceiver is very simple - set the first VFO to 145.000 USB for reception and set the power level to 0 (LOW) ! Set the second VFO to 435.650 LSB with normal power level. On the first VFO, enter the M1 menu and press the SPL button, what you get 145.000 USB and split will appear on the display. Press PTT and see 435.650 LSB during TX transmission, release PTT and you will return to 145.000 USB. Save the specified setting to memory.
Another trick is to find yourself on the passband. First of all, find the satellite beacon signal on 145 MHz and set your receiver to approx 10 kHz above. The beacon frequency on the uplink is 435.655 MHz (do not broadcast here, you would be interfering with the beacon signal), set the transmission frequency about 5kHz lower and transmit briefly (say "hello" for example). Then quickly release the PTT, retune the receiver o 1-2 kHz down until you pick up your own signal with the reverse delay from the satellite. After capturing the signal, tune the receiver for good readability and that's it.
Author made many stations from all over the world with this setup and many hams 🙂 were surprised, how easy it is to work via satellite. Try this method.
A way to use one coax to feed the uplink antenna and the downlink converter with one device, for example. IC-706MKIIG. The diagram shows the modified wiring of the MFJ duplexer.
