J pole feed
On 11/10/2010 9:04 PM, tom wrote:
On 11/10/2010 7:40 PM, VK2KC Gmail wrote:
Hello,
I have just built a J pole antenna for the local our local Emergency
Service
centred on 410 Mhz for their field/portable use.
I note that the Arrow antenna feeds the 1/4 w/l element directly, but the
standard J pole feed is on each element.
What works best? The standard J pole feed or the way Arrow feeds theirs?
Cheers John
VK2KC
I could reply as one here does and say -
YES
And then he would leave it there and scold you for not knowing how.
Neither feed is superior. The issue you need to address is that this is
a balanced antenna fed by an unbalanced feedline.
So your mission is to lessen the current on the outside of the coax.
This involves a choke, which could be ferrite based or coiling the thing
up based. I won't get into it beyond this since it's all out there with
google search and google news search.
tom
K0TAR
And if you have more questions, don't hesitate to ask.
tom
K0TAR
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