Back on 40m by removing loading coils!

My multi-band fan dipole antenna with elements for 40, 20 and 10m had developed ‘HI SWR’ after adding loading coils to 40m elements to work on 80m. It had ‘HI SWR’ on 80m as well. Other band elements were still functioning well. So I was virtually cut off from the 40m band which I enjoyed very much for local contact. Yesterday morning I removed the loading coils for 80m from the 40m elements. SWR came back to around 2 on 40m. I had not tuned the elements well after removing the loading coils. Hence the SWR did not return to the 1.1 at lower end of band as before. Still it was tunable with built-in antenna tuner of FT-710 radio. After that I could have comfortable contacts on 40m band yesterday morning, on SSB.

Today morning I checked propagation on 40m band using Reverse Beacon Network. I called CQ in CW on 7010 kHz for a couple of times and checked RBN for spots. Automatic CW skimmers in Europe at distances of 6000 to 7000 km had picked up my signals with signal to noise ratio ranging from 3 to 10 dB. That was good performance for an inverted V antenna with apex at just around 10m from ground and 100W of power in my FT-710 radio. I always use Reverse Beacon Network to check antenna performance after any modifications. It is an objective evidence and is accessible online to anyone, even at a later date. As it is an automated process, there is no human bias as in signal reports received from other amateur radio operators. Problem would not have been that of the loading coils, because I had not gone through the meticulous process of tuning after adding the loading coils.