Measuring the TinyFilter with a NanoVNA
I recently had the wonderful opportunity to work with Ara, N6ARA, on the TinyFilter - a 2m bandpass filter for hand-held VHF amateur radios. The filter is offered both as an assembled unit and as a kit. For both versions, many people have been wanting to measure the tuning and performance with a nanoVNA, and we've been getting a few questions on how to do this properly. One area of difficulty that people have had is that measuring a filter is different than measuring the SWR of an antenna. I suspect many hams use their nanoVNA for antenna tuning, which requires a less extensive calibration procedure than measuring a filter. In this note, I'll walk through the steps of calibrating the nanoVNA and measuring a TinyFilter, with lots of pictures. The equipment needed is shown in the photo below. There is the nanoVNA, of course (shown on the right). The picture shows the filters to be measured, both a BNC version with its orange label and an SMA version with a clear heat shrinking...
