K
kf6wtc
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Hello everyone. I am having trouble with a dipole and hope you can help.
Not long ago I bought a HI-Q 10 meter dipole from a local ham shop. The kit came with a Hi-Q balun, 9 gauge copper wire, 2 insulators and nilon rope.
I want to cut this dipole to use on 11 meter SSB. I used a dipole program I found online to find the lengths of each leg. According to this program it says at 27.205 Mhz that each leg of the dipole wil be 108.46 inches. I tried this length and my swr is not even close to being resonate. Next I turned to the instructions that came with the dipole.
According to the instructions it says that at a total assembled length (including the 3" balun) of 16' 4" that the dipole will be resonate at 28.0/29.7 Mhz. I decided to setup an equation with this information.
To setup this equation I first decided to find the middle between these to frequencies
28+29.7/2 = 28.850 Mhz
Then I took the length of 16' 4" and converted it to inches:
16' * 12 = 192 + 4 = 196"
Next I setup a ratio:
28.850/ 196 * 27.205/x
196*27.205/28.850 = 184.82"
Now this is where I get confused. The length I have come out with is smaller than the length of the 10 meter number. As you get lower in frequency the longer the length of the antenna is suppost to get.
Next I thought I should find the difference between the two lengths and then add that number to the orginal 10 meter length.
196-184.82 = 11.18"
Which would give me a new length of 196+11.18 = 207.18"
Now subtract the 3 inches of the balun:
207.18-3 = 204.18 (legs)
and then divide that in half 204.18/2 = 102.09" (each leg)
Did I do this right? 11 extra inches seems like alot.
Thanks for your time!
Michael
ps. The dipole program told me that each leg at 27.205 would be 108.46. That's a diffence of 6.37"!!
</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=kf6wtc>kf6wtc</A> at: 1/27/05 8:27 pm
Not long ago I bought a HI-Q 10 meter dipole from a local ham shop. The kit came with a Hi-Q balun, 9 gauge copper wire, 2 insulators and nilon rope.
I want to cut this dipole to use on 11 meter SSB. I used a dipole program I found online to find the lengths of each leg. According to this program it says at 27.205 Mhz that each leg of the dipole wil be 108.46 inches. I tried this length and my swr is not even close to being resonate. Next I turned to the instructions that came with the dipole.
According to the instructions it says that at a total assembled length (including the 3" balun) of 16' 4" that the dipole will be resonate at 28.0/29.7 Mhz. I decided to setup an equation with this information.
To setup this equation I first decided to find the middle between these to frequencies
28+29.7/2 = 28.850 Mhz
Then I took the length of 16' 4" and converted it to inches:
16' * 12 = 192 + 4 = 196"
Next I setup a ratio:
28.850/ 196 * 27.205/x
196*27.205/28.850 = 184.82"
Now this is where I get confused. The length I have come out with is smaller than the length of the 10 meter number. As you get lower in frequency the longer the length of the antenna is suppost to get.
Next I thought I should find the difference between the two lengths and then add that number to the orginal 10 meter length.
196-184.82 = 11.18"
Which would give me a new length of 196+11.18 = 207.18"
Now subtract the 3 inches of the balun:
207.18-3 = 204.18 (legs)
and then divide that in half 204.18/2 = 102.09" (each leg)
Did I do this right? 11 extra inches seems like alot.
Thanks for your time!
Michael
ps. The dipole program told me that each leg at 27.205 would be 108.46. That's a diffence of 6.37"!!
</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=kf6wtc>kf6wtc</A> at: 1/27/05 8:27 pm