Topband: DX0JP Antenna

Bill Tippett btippett at
Fri Feb 16 07:14:44 EST 2007

         I received the following from Hiro JA4DND who
operated Topband from DX0JP:

>I set up 2el phased array for TX ,2 directions beverage and K9AY for RX
>But 2el phased array is better than beverage for EC
>I think the reason why is inverter noise from solar house in the 
>island ,not sure
>2 ele phased array was setting N and S beam,  I beam to S for EC and 
>N for EU and JAs
>FB ratio is about S4 unit ,
>element length is about 21.5m for vertical unit(11.5m of AL pipe and 
>10m glassfiber lot) + 20m wire(0.9mm dia)
>6 wire radials was set  per each element and COMTEK  PCS2V
>Material of radial is all aluminum (1.5mm dia) and some of radials 
>go to in the sea.
>we have to bring a lot of radials for 40m and 80m 4SQ too
>.from my memory Total length of radials are about 1300m
>But not so heavy caused by aluminum wire

         Some of us noticed Hiro's signal would suddenly
appear and then disappear.  This was apparently caused when
he switched his phased array from North (to EU/JA/Western NA)
to South (Eastern NA via long path).  Before his trip I explained to
Hiro that our best chance for EC-NA might be via LP which would
also avoid the BY Dragon to the north.  Fortunately the Dragon
was relatively quiet during the expedition.

                         73,  Bill  W4ZV 

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