Measurements and analysis suggest why quarter-wave stubs fail to completely isolate radiator conductors on multi-band antennas including the popular rollup 2m/440 J-Pole products. Possible improvements are shown.
You would think the world of RF connectors of the pedigree of the “N” would rigorously follow the dictates of the standards that define them. Thankfully most do, but exceptions arise and here is one such example of why it pays to “trust, but verify.”
The National Institute of Standards and Technology appears to have the time and frequency broadcast stations on the chopping block given the info contained in their 2019 budget proposal. This is what I wrote to my senator and congressman.