|Jim 2I0SBI and Pat EI2HX cleaning the trap assemblies|
The first task was to take the mast off the wall brackets and lean it over enough for me to be able to remove the minibeam from atop the extension roof. This only took a few minutes. The MA5B is light enough that I could hand it down to the two lads.
|The matching network was in good condition|
The driven element provided a few surprises. We found that the trap in the "hot" leg of the driven element (labelled MT1) had suffered a drastic melting of the insulator. We are not entirely sure how this might have affected the performance of the antenna because the 2mm-thick aluminium wire wound around the insulator is actually connected to the casing of the trap also.
|The burnt trap insulator before cleaning|
In addition to the above we found that the connections on the driven element had all suffered from corrosion, which was evident from the amount of white powder we found when disassembling the trap joinings and the element connections. All of these were cleaned up with emery paper and wire brushing. This took quite a bit of time because all the joints had been well sealed with tape and were also clamped with jubilee clips. But having three pairs of hands made light work and in no time at all the driven element had been given a thorough overhaul.
This work even included cleaning the nuts and bolts and washers where the coax joins the two driven element sections. We decided it was best to make a good effort so that the antenna might give a good few years of use if needed. After all it has been at this QTH for a couple of months but only getting very limited use.
|Yours truly reattaching the minibeam to its mast|
However, for now some of the problems with the minibeam have been resolved and it is now resonant on 20 metres CW where it had a high SWR before. I will put the beam through its paces in the coming days and will report on progress here.
In the meantime, a big thanks to Pat and Jim for the help.