If you go to a metal fabricator/engineering shop in the typical industrial area, phone first to see if they do aluminium. They all have an offcuts bin, so you can usually find a few small pieces about the right profile. Cheaper than those big hardware stores.
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Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
The best spot for an external aerial is where Peter_n_Margaret suggested.
With the absence of a bull bar, the next best is the Z mount on the edge of the bonnet.
Be wary that there are several types of aerials too. High gain ones (6-9dB) tend to have a narrow signal path; I recall the 3dB gain ones tend to be the most used, giving a wider but slightly weaker transmit/reception path.
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Warren
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If you don't get it done today, there's always tomorrow!
I use zero or 1db gain antennas on the OKA. They are short, cheap and almost indestructible.
They give the clearest transmission and reception for a shorter distance (10km instead of 30km, as a comparison) and work better on undulating and hilly terrain.
I don't want to hear every tourist or truck for 30km in every direction.
Cheers,
Peter