UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 405-Line VHF Aerials 2013 to the present day.

SteveCG · 29th Dec 2015, 2:35 pm

Re post no. 318:

There were two versions of Antiference's combined Band III/ UHF aerials. The picture shows the original (Mk 1 shall we say?). Note on it, the hanging balun junction box for the UHF and the near in-line junction box for the Band III. The Mk2 used the first version of Antiference UHF Trumatch dipole and the Band III junction box was the offset style virtually identical to the one used on later Band II aerials. Whilst the UHF trumatch dipole was an improvement, it was somewhat compromised by the Band III junction box being a serious fraction of the UHF wavelength for Group C so 'detuning' the UHF yagi design.

In my opinion Antiference would have been better to have kept the MK 1's Band III junction box. This UHF 'detuning' would have been less for the Belmont design with its Group A UHF yagi element lengths.

I can remember seeing quite a few of the Winter Hill designs in use around its service area.

29th Dec 2015, 2:35 pm	#330
SteveCG Nonode Join Date: Jun 2009 Location: Herefordshire, UK. Posts: 2,495	Re: 405-Line VHF Aerials 2013 to the present day. Re post no. 318: There were two versions of Antiference's combined Band III/ UHF aerials. The picture shows the original (Mk 1 shall we say?). Note on it, the hanging balun junction box for the UHF and the near in-line junction box for the Band III. The Mk2 used the first version of Antiference UHF Trumatch dipole and the Band III junction box was the offset style virtually identical to the one used on later Band II aerials. Whilst the UHF trumatch dipole was an improvement, it was somewhat compromised by the Band III junction box being a serious fraction of the UHF wavelength for Group C so 'detuning' the UHF yagi design. In my opinion Antiference would have been better to have kept the MK 1's Band III junction box. This UHF 'detuning' would have been less for the Belmont design with its Group A UHF yagi element lengths. I can remember seeing quite a few of the Winter Hill designs in use around its service area.