| Author |
Message |
    
Charliebrown
Member
Username: Charliebrown
Post Number: 72
Registered: 10-2002
| | Posted on Tuesday, June 01, 2010 - 6:35 pm: | 
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Years ago I had an old metal antenna and I had it about 8 feet above the ground. I tried it with the ground plane and without. I put the antenna in the exact location, height, and same cable, with no diference in receive or transmitt. I used the same people for a radio check without them knowing what I was doing so the check would not be biased. There was no difference. I also did the a-99 the same way only at a different height with the same results. I have seen people swear that the gpk has helped them soo much. Could anyone tell me why some people swear there is a difference and I could not. What could I be doing wrong for me to have these results so different than others? HELP ME GUYS. I AM ALWAYS LOOKING TO LEARN MORE. AND I AM ALWAYS LOOKING TO IMPROVE MY STATION. I WOULD BE VERY GRATEFULL FOR ANY HELP...THANKS. |
Tech833
Intermediate Member
Username: Tech833
Post Number: 193
Registered: 12-2001
| | Posted on Wednesday, June 02, 2010 - 1:41 am: |
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Normally, for a half wave end fed antenna (like the A99), if the feedpoint is more than 1/2 wave above ground, the GPK will do nothing at all.
Now, for the Imax 2000 and other 5/8 wave type antennas, the GPK will lower the takeoff angle regardless of height above ground. Do a search for the Imax 2000 Exposed and it's companion article of the GPK review. Field plots can be found there before and after adding the GPK so you can see what is going on.
Your radio 'Mythbuster' since 1998
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Charliebrown
Member
Username: Charliebrown
Post Number: 73
Registered: 10-2002
| | Posted on Wednesday, June 02, 2010 - 6:30 am: |
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TECH 833, How are you doing? It is good to here from you again and I thank you for the info. I going to be buy a gpk for my IMAX and I hope it will improve my station enough to make it worth my effort. My IMAX is about 30 feet off the ground and it does a great job the way it is but, just like autos and other things I always want the best I can get out it...Thanks again and I hope you and yours have a great day |
Tech833
Intermediate Member
Username: Tech833
Post Number: 194
Registered: 12-2001
| | Posted on Wednesday, June 02, 2010 - 11:33 am: |
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Thanks a lot Charliebrown. May I just call you C.B.?
When you pu the GPK on your Imax, remember to bend the bracket so the radials are closer to 30 degrees from horizontal. As it comes, they are too vertical.
Your radio 'Mythbuster' since 1998
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Charliebrown
Member
Username: Charliebrown
Post Number: 74
Registered: 10-2002
| | Posted on Sunday, June 06, 2010 - 8:12 pm: |
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TECH 833, Sorry it has taken soo long to get back to you but, I have had both sides of my family in and they have kept me very busy. YES YOU CAN CALL ME C. B. I have been asking questions on this forum for more years than I care to mention. You and other techs and some other people have helped me and have been soo nice, that it would be hard for me to express in words other thanks a million for all the advice and for all of what everyone has taught me over the years. It is soo hard to find good friends and people that will give good truthfull advice. It is good to know that it can be found here....ONCE AGAIN THANKS A MILLION AND MAY GOD BLESS YOU ALL..... |
Mikefromms
Senior Member
Username: Mikefromms
Post Number: 1031
Registered: 6-2003
| | Posted on Tuesday, August 10, 2010 - 2:45 pm: |
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A 1/2 wave is ok by itself. |
