Wednesday, February 16, 2011

Making a slim jim


made one of thease on me foundation course thease are the smae plans we used.slim jim using both 300 and 450 Ohm Feeder and have found the 450 feeder to be easier to SWR..

TO swr the Slim jim simply hang the antenna in free space away from metal objects and make sure the Coax runs straight down below the antenna.Then simply move the feed point up or down slightly until best swr is achieved..

The slim jim is Basicaly a Half wave vertical with a quarter wave matching stub so you can calculatefor any band by simply working out a halve wave length for the Longestlenghth, 468/f in mhz,and for the quarter wave length 234/f in mhz and answers in feet.To match simply adjust the feed point as on the 2m version.also worth consideration is the J-POLE seen below

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