| Author |
Message |
    
Skilletlicker
Intermediate Member
Username: Skilletlicker
Post Number: 216
Registered: 5-2002
| | Posted on Saturday, June 04, 2005 - 1:24 pm: | 
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what i dont understand is how thw gpk works where it is installed looks to me like it would work better on the part that raditates or the fiber glass part
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Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 344
Registered: 6-2004
| | Posted on Saturday, June 04, 2005 - 2:53 pm: |
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The fiberglass part of the A99 is the driven element of the antenna. If you installed the GPK there it would add to the driven element and do nothing beneficial. It would change the radiation pattern and possibly even change the resonant frequency of the antenna.
It's intended to add radials to the 1/2 wave end fed antenna. For resonance, radials aren't necessary, but they do accomplish a couple of things. The most practical thing they do is decouple RF from the feedline preventing it from traveling down the shield of the coax creating a strong local RF field that can cause problems for electronics. The second thing it does is help the radiation pattern of the antenna to become uniform and even lower the radiation angle of the antenna to give it better gain.
You can also decouple RF from the feedline by creating a coax choke and it'll only cost you the price of several feet of coax. Depending on the flexibility of the coax you're using you can coil it tightly around the mast you've used to mount the antenna or you can use UV protected zip ties to create a coil just below the feed point. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 629
Registered: 7-2004
| | Posted on Saturday, June 04, 2005 - 5:54 pm: |
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I have never noticed any power gain
on transmit or recieve using a GPK.
But, i have noticed the benefits that
hollowpoint445 mentions in his post.
JIM/ PA/ CEF 375 |
Skilletlicker
Intermediate Member
Username: Skilletlicker
Post Number: 219
Registered: 5-2002
| | Posted on Sunday, June 05, 2005 - 8:42 am: |
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thanks for the info
the skilletlicker
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Skilletlicker
Intermediate Member
Username: Skilletlicker
Post Number: 220
Registered: 5-2002
| | Posted on Monday, June 06, 2005 - 11:22 am: |
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hen i would be as well offto make an coax choke
the skilletlicker |
Indiana375
Junior Member
Username: Indiana375
Post Number: 43
Registered: 3-2005
| | Posted on Monday, June 06, 2005 - 2:26 pm: |
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I have the GPK on my A99 and the only thing that I noticed was a lower SWR. |
