de Jay W5JAY
The Perseus SDR is an excellent stand alone receiver with features such as a wide band scope, recording MP3s for audio as well as huge chucks of spectrum, sync AM, a GUI console, etc. Adding the Perseus SDR to an all ready excellent transceiver such as the Icom 7700 really adds capability for the hunter/DXer. Even Icom transceivers with Dual Watch, such as the Pro 3 and 7600 series of rigs, cannot equal a true second receiver, where each frequency is split out into a headphone ear cup for weak signal DXing. The bandscope on the Perseus will see weak signals that are buried in the grass of an Icom transceiver's bandscope; this is shocking to see, but a welcome improvement. You can change BobCAT's display from bandscope to waterfall to instantly recognized modes like CW. There are times when pointing and clicking with a mouse on a signal is faster and more precise than using a tuning knob; there are other times when it is nice to use the transceiver's tuning knob to synchronously tune both the transceiver and Perseus. As anyone who has used an SDR before will tell you, the GUI console provides much more than just the ability to change modes and settings. Filtering out interference with a mouse is faster, more effective, and more precise than using your ears and a transceiver's front panel controls. Using a Perseus with BobCAT's GUI interface can provide huge advantages over a normal receiver. When operating PSK, for example, you can see how to move the notch to filter out W1AW, something much harder to do with ears alone.
To operate a Perseus in parallel with your Icom transceiver, you'll need a way to connect an antenna to both radios when receiving that disconnects the Perseus from the transceiver's RF output when transmitting. This is straightforward with a transceiver like the IC-7700 that provides an RX antenna in and RX antenna out signals on its backpanel. I use a [ http://www.minicircuits.com/pdfs/ZSC-2-1W+.pdf Mini Circuits ZSC-2-1W+] splitter.
The splitter has three ports, the S or source port is connected to my IC-7700's RX antenna out connector. Splitter port 1 loops the antenna signal back into the IC-7700's RX antenna in connector and splitter port 2 is connected to the Perseus's antenna connector. Configured in this way, signals coming down the feedline to the IC-7700 will also feed the Perseus's antenna port at the same time. When you transmit, this configuration also helps knock down the received signal on the Perseus. The IC-7700's RX antenna in and RX antenna out signals are by default deactivated, and must be activated via the radio's antenna set screen. You'll also need a relay on the Perseus audio output to provide muting when transmitting.
You will loose 3 dB of signal by using a splitter, but don't let that scare you off. I rarely use the IC-7700's preamps, especially on the lower bands. I can measure and see the loss, but it has not been an issue. However, don't scrimp on a cheap splitter or cables. I use high grade double shield Teflon cables and BNC connectors to match. The last thing you want is to add birdies and spurs from other sources in the shack from cheap poorly shield cables. Keep these cables short as possible, ideally under 2 feet long.