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Old 17th May 2014, 11:02 am   #143
SteveCG
Nonode
 
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,495
Default Re: 405-Line VHF Aerials in 2013

Gulliver,

Often the connections corrode inside the dipole junction box. Indeed the southward pointing (towards London's main TV transmitter - Crystal Palace) UHF aerial is a J-Beam MBM design (easily recognisable by its bent X type directors and its 'square-back' dipole and reflector). These were reasonable aerials for the time but unfortunately they suffer from corroded junction box innards which mean they don't work these days - unless they are mounted inside, in the loft say. The other UHF aerial pointing towards Sandy Heath could well be an Antiference make. These too can suffer from corroded junction box contents; so putting an aerial in the loft was a good idea !

The UHF aerial you bought from Tandy has a good chance to be a 'wide-band' design ( Group W - colour code black).

BTW whilst I do not recommend going on a roof unless you know what you are doing, if you ever did that you could expect the tip-to-tip element distance for the 'H' dipole to be about 5 feet if it is a VHF/FM aerial and about 7 foot, six inches if it was a TV aerial for the old Peterborough, Channel B5, 405-line TV transmitter.
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