TechMinds: Testing a DC-160 MHz Panadapter Switch
Over on his YouTube channel Tech Minds has uploaded a video where he tests out a cheap US$90 automatic antenna switch with DC-160 MHz range that he purchased from Chinese goods retailer Banggood. An automatic antenna switch like this is required when wanting to use an SDR such as an RTL-SDR as a panadapter with a transmit capable radio. The switch will automatically switch the SDR to ground when transmitting, so that high power does not enter the SDR via the shared antenna and destroy it.
In the video Tech Minds shows how to set the switch connections up and then demonstrates the switch in action with a Yaesu FT-991A and SDRplay SDR. He notes that this cheap Chinese version is actually built better than the MFJ-1708 antenna switch which until recently was the only commercial option available. It is also half the price.
I bough one of these a while back, good thing I tested it, or I’d have fried my SDRPLAY Duo. It works but is unreliable – Yes I wired up the PTT – I also like to drop the SDR randomly and there is random relay chatter when it is just sitting there. I have RFI chokes on pretty much everything. I think the problem might be the power connector, I have not yet but am planning on soldering a power line rather than relying on the cheap little connector. If you buy one, test it before you put it into service.
Price dropped 40%
“which until recently was the only commercial option available” – this maybe inaccurate 🙂
I use this TR Switch for quite some time now – https://www.sv1afn.com/en/products/trs-450-transmit-receive-switch-rx-interface.html