Topband: 300 ohm

[Rodman, David]

Joe, I have had some trial with this bidirectional setup many years ago.  Although having a NE and SW listening antenna is quite desirable for stations in the NE USA, I have experienced repetitive mechanical failure with this system.  In the wind, no matter what wire diameter twin lead selected, wind tends to create constant twisting of the antenna.  Perhaps, I chose distances between supports that was too long?  However, one can see the antenna constantly twisting and moving in any appreciable wind.  I did not get more than 8-9 months from each attempt.  I tried it for 2-3 years and gave up.  Perhaps if supports were shortened to every 20 ft, this could be better managed?  Once the twinlead breaks, it may be hard to find the repair spot by observation as the antenna is so long.  For a decent length beverage, say 800 ft, this is lots of supports and can be lots of maintenance.  For me, the failures were always in the winter when it was difficult to repair and when you needed the antenna most.  I also tried the coaxial cable RG6 bidirectional and was not overly impressed with that either.  For bidirectionality, one needed two feed lines and lots of mechanical support to the antenna in order to keep the connectors from pulling off.   It worked for 2 years without repair.  I abandoned that antenna and used the two transmission lines for phased SAL-30 arrays which have been much more mechanically stable (and offer multiple directions) at my location.   Those tend to stay up for years without mechanical failure or needing any maintenance, although they may not play as well as a long beverage.  I hope this helps you.




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David J Rodman MD
Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo

Office 716-857-8654