Use a laptop, use a BT to serial or WiFi to serial adaptor.
On Mon, 2 Dec 2024 at 20:26, Brent DeWitt via groups.io
<bdewitt@...> wrote:
Measuring balanced antenna feeds with the nano is easy if it is not connected to anything and well decoupled from "ground". It would be nice to remove the influence of connecting a USB cable to a PC so NanoVNA Saver can be used. I see two possible solutions:
- a wideband RF 1:1 transformer on the S11 port
- USB isolation of the RF path to ground
The nice thing about USB isolation is that it should be possible to make it generically broadband and there are lots of isolators out there cheap. As one might expect, none of the inexpensive products (not fiber optic) say anything about parasitic capacitance on the ground side. Does anyone on this list have good/bad experiences with specific brands and models that show low coupling in the 3 to 30 MHz region?
failing that, I'm thinking the RF transformer may be the best way to go.
All thoughts welcomed!
Brent, AB1LF
