Often seen at club meetings in the “Free to good home” heap, there seems to be an inexhaustible supply of HF mobile whips, generally out of the mines in South Australia or Northwest Queensland, similar to a Terlin “Outbacker”, but of, course, custom wound to commercial HF frequencies temptingly close to amateur allocations, but no cigar. You could, of course, break open the appropriate windings, and reduce the number of turns (assuming you want to go up, not down, in frequency), but that would almost certainly impair the the robustness and watertightness of the assembly. I was given, for free, a pair of these Terlin clones with a tap for 6846 kHz, close to our 40 mtr allocation, but, given the fairly high Q of most helically wound mobile whips, it may as well have been the opposite end of the spectrum. My test subject actually came in closer to 6750 kHz, probably because I had misplaced the original “wander wire”, and grabbed something off the bench that was clearly too lon