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#1
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How does one check the balance between two parallel feed wires into a
doublet antenna. Neon bulbs or some sort of meter gizmo? tnx d |
#2
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That topic was discussed in some detail on this newsgroup just a few
weeks ago. Do a search in groups.google.com of this newsgroup for the topic "unbalance indicator". Roy Lewallen, W7EL Big Endian wrote: How does one check the balance between two parallel feed wires into a doublet antenna. Neon bulbs or some sort of meter gizmo? tnx d |
#3
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How does one check the balance between two parallel feed wires into
a doublet antenna. =========================================== Just go out into the garden and look up at the antenna. If each half of the doublet is of about the same length, and both halves are about the same height above ground, then the parallel pair of wires are balanced. ---- Reg. |
#4
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Big Endian wrote:
How does one check the balance between two parallel feed wires into a doublet antenna. Neon bulbs or some sort of meter gizmo? tnx d YEP!! An RF Ammeter will do just fine |
#5
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Amos Keag wrote:
YEP!! An RF Ammeter will do just fine Balance requires that the currents in the two wires be equal in magnitude and opposite in phase (or direction). How do you connect an RF ammeter to determine this? Roy Lewallen, W7EL |
#6
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Wouldn't the clamp-on type ammeter as discussed previously provide that
information (provided a section of twin lead small enough to fit the clamp were used? Chuck Roy Lewallen wrote: Amos Keag wrote: YEP!! An RF Ammeter will do just fine Balance requires that the currents in the two wires be equal in magnitude and opposite in phase (or direction). How do you connect an RF ammeter to determine this? Roy Lewallen, W7EL |
#7
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![]() "Roy Lewallen" wrote Balance requires that the currents in the two wires be equal in magnitude and opposite in phase (or direction). How do you connect an RF ammeter to determine this? ===================================== It's unbelievably easy Roy, you just pass both wires together through a clamp-on ammeter. ---- Reg. |
#8
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Reg Edwards wrote:
How does one check the balance between two parallel feed wires into a doublet antenna. =========================================== Just go out into the garden and look up at the antenna. If each half of the doublet is of about the same length, and both halves are about the same height above ground, then the parallel pair of wires are balanced. In your opinion. But the original questioner wants to measure what's *really* happening. -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
#9
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Big Endian wrote:
How does one check the balance between two parallel feed wires into a doublet antenna. Neon bulbs or some sort of meter gizmo? The easiest way is to use a large sampling toroid such that the balanced line can be fed through the toroid. A ten-turn sampling coil will indicate any unbalance. Note that the balanced line needs to be centered with respect to the toroid and needs to be moved along the feedline to obtain maximum accuracy. Ideally, the toroid needs to be located at a standing wave current maximum point. Since my choke-balun is always located at a current maximum point, I can easily monitor my feedline balance. You can also use smaller toroids on each line and then superpose the two readings. But the two toroids need to be identical which is no small requirement. -- 73, Cecil http://www.qsl.net/w5dxp |
#10
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Reg Edwards wrote:
If each half of the doublet is of about the same length, and both halves are about the same height above ground, then the parallel pair of wires are balanced. What if one is broken and you don't know it? -- 73, Cecil http://www.qsl.net/w5dxp |
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