Re: 405-Line VHF Aerials in 2013
Re posts 51 & 52.
I concur with those who say J-Beam's UHF MBM range was not all it was cracked up to be. In later years J-Beam's/ Jaybeam's advertising started to reflect the more real figures. I think this was because of the adoption of a measuring standard.
However when it comes to the UHF PBM range - I'm much more of a fan, a PBM 18 element, Group A, especially the early, more rugged, 'squareback' reflector type is a sight to behold - and a repectable performance.
J-Beam used what they called an inverse balun to effect a 300 Ohm Balanced to 75 Ohm unbalanced transformation - for use with 75 Ohm coaxial cable downleads.
The main problem with all these aerials is the contact corrosion in the junction boxes.
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