Category Archives: Blog

Building a Delta Loop for 10m

This post will hopefully encourage you to experient with more aerials/antennas and try different types for your location! The delta loop is a full wave antenna that is usually fed with a 50-ohm coax via a 4:1 balun or 75-ohm matching section, depending on the build. Also, where you attach the coax will affect the… Read More »

Coax Loss Chart

Following on from George, GI4SJQ’s talk on coax and connectors, here is a chart of the more popular coax type and their loss. Also calculated is the dB loss and power out for 20W in over a 20m length, for both 145MHz and 435MHz. For comparison there is an additional column of price per meter… Read More »


For those of you who have been following along our videos from the clubs Tuesday Night Lecture Series it has not got a lot easier. You can go to and that will bring you to our Youtube channel with all our previous lecture videos and much more content in the pipeline. Visit the channel,… Read More »

50MHz/70MHz diplexer, part 2

I bought a NanoVNA to properly measure the 6m/4m diplexer. The results were mixed: So, testing the 70MHz high pass showed that there was 22dB attenuation at 50MHz. Not too bad! I could try adjusting the coils for more attenuation, but there was no de-sense on the 4m radio So I’m happy to leave it… Read More »

50MHz/70MHz diplexer

I don’t have a huge garden for an antenna farm, so most of my antenna experiments are located in the attic. Also keeping the neighbours happy, and most importantly, the station manager happy, is a priority! I have several runs of RG213 and RG58 into the attic, but wanted to be able to use 4m… Read More »