I’ve noticed these odd looking aerials before, but today I finally got my hands on one. The thing is obviously supposed to be a wideband UHF aerial. The design is terrible, though. The 16 directors are about the correct length for Group C/D. In fact there are just two lengths of director, 140mm and 145mm. The folded dipole is just that, a folded piece of tube with no balun or attempt at impedance matching. It is 255mm across, about right for Gp A.

Now as any skuleboy kno, a reflector for ch21 needs to be no less than 340mm – much shorter and it will act as a director, if anything. The reflector on this aerial is a miserable piece of thin plate 265mm across, so it can’t possibly be helping. It’s spaced about 2/3rds of a wavelength from the dipole, and I think it’s a standard reflector from a Gp B or CD cheapy array.

I found this miserable turd on a stick pointing at Crosspool transmitter in Sheffield. This was in an area with which I’m not familiar, so when I metered the output and found all the signal levels from 21 to 67 very low, and when I saw the terrible ghosting on the analogue channels, I assumed that I was in a bad reception area.
Having hauled my not inconsiderable bulk onto the roof, plus an analyser and a test aerial, I was amazed to see Crosspool giving me a cheery grin from across the valley.