TS-480 with SDR and Remote Operation

2017/01/08
JE3PRM (WE3PRM)
Shingo Takimoto

[System Configration]
In the time of RX, the signal from the antenna is divided two line by the hybrid circuit with two amplifiers. One line is for TS-480,the other for SDR. That makes the TS-480 and SDR can work together at same time. The SDRconsole is used as S/W of SDR and when the frequency is set on the screen of spectrum of SDR, its data is set on theTS-480 automatically with OmniRig function of SDR. Some function related with TX mode in TS-480 can be set on PC by the PC program made by myself. It is put between OmniRig data stream and the command line of TS-480 with virtial COMport like Com0Com. That makes so called "remote operation" can be done with the remote desktop for PC.

[Signal divide circuit]
In the simple way to use SDR and a transceiver, you need one relay only to switch to SDR at RX and to transceiver at TX. In this system, Switching of TX/RX is done with OmniRig function of SDR. However, It takes time to switch, 0.2 to 0.5 seconds. it is no problem for normal QSO, but in case of quick QSO like contest, it make us frustrated. In that case, the best way is that you see the band scope on PC by SDR and set frequency with muse operation on PC and hear voice from the transceiver. In order to do this, I put the signal divider into antenna input. The diagram is as below. Basically signal can divided with T1 and R2 only. But I put buffer amplifiers to compensate loss of T1 and R2, to match the antenna impedance of 50 ohms, and to increase isolation of each other receiver. The FET Q1 and Q2" are J211(Fairchild). The relay is controlled by RX/TX control signal from the TS-480 and DTR of RS232C connected with PC.

[Remote Operation]
I use Team Viewer as remote operation system, not special program for ham radio like HRD, or ham-radio-deluxe. It works under the windows home edition as host and client. With this system, I can not only see the band scope on the remote PC, but also handle all operation including log fie on the host PC. Regarding voice transmission or VoIP, I use Skype, since the VoIP functiion of Team Viewer does not work well.