SDR Transmit/Receive Switch
One of the coolest things about our little MFJ company is the way we are able to adapt and come out with a new product in one or two days. For instance, we get a call from one of the leading SDR players, he says they have been modifying a current product of ours for their SDR radios and voila!
The next two days we spit out a silk screen, have K1BQT write some beautiful copy, we make a prototype and we are ready to sell it just in time for Christmas! A production run is scheduled . . .
SDR transceivers are great, with colorful waterfall displays that accurately present everything there is to see across the band at a single glance. If you want to know where the activity is, who’s generating splatter, what’s happening in the DX window, how wide your audio is, or what frequencies are clear for calling CQ, it’s all right there!
Unfortunately, it’s information you won’t get from your conventional radio without wasting a lot of time tuning around. Fortunately, you don’t need to get rid of that perfectly good rig to go SDR, thanks to miniature
wide-band SDR receivers like SDRplay’s RSP family — now available at a station-accessory price. All it takes is a convenient way to pair one up with your transceiver. That’s where the MFJ-1708SDR comes in. Here’s how it works . . .
SDR T/R Switch
The MFJ-1708SDR provides a matched-in signal splitter, so your transceiver and SDR unit share the same high-performance antenna system. This arrangement allows you to simultaneously watch and listen. Then, when you key up to transmit, the MFJ-1708SDR cuts off and grounds the SDR antenna line, providing your SDR with bullet-proof protection from damaging RF. It’s the perfect plug-and-play solution for upgrading your shack to wide-screen living color.
MFJ-1708SDR uses the PTT signal from your rig to initiate the switching, but as a failsafe measure, built-in RF sense circuitry will provide a measure of safety if the PTT connection is lost.