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HamTrain Foundation Online: Feeders and Antennas
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- เผยแพร่เมื่อ 18 ส.ค. 2024
- Looking to take your UK Foundation exam? The Foundation Online course from Essex Ham can help.
This is the fourth part of the Ham Train "Foundation Online" training course - Feeders and Antennas.
Our free online course covering all of the Foundation syllabus is available at: www.hamtrain.c...
A Good video; I was impressed that a field diagram was shown for the dipole, and was then disappointed that these diagrams didn't continue on the next slides. You also failed to point out that the electromagnetic field doesn't actually touch the antenna, and will travel further away as the height of the antenna above ground increases.
Sorry to hear that you’re disappointed with our free course material. As per your previous negative comment, we are only following the RSGB exam syllabus and your point is not required learning for your Foundation exam. You’ll cover this when you study for your Intermediate exam
Actually, it is not how an antenna gain works. It is not increasing the power, because it would contradict the conservation of energy. So if you feed 5 watts you will not get 10 watts but, of course, in the main direction the power density will be 2 times higher than from the reference antenna (isotropic or dipole).
Agreed - Remember that this is Foundation-level, which simply requires a basic summary of ERP. Higher levels go into this and other subjects in more detail. Good luck with your studies and exam.
Using a single antenna on a band its doesn't resonate on may be possible with a ATU to convince the radio you have a resonant antenna connected to it, but you will receive very little signal and will transmit even less because the antenna resonance is required for the creation of an Electro Magnetic Field which will not happen on a non-resonant antenna, worst still like the G5RV you have the feeder line becoming part of the antenna and start transmitting energy where you don't want it transmitted.
I think this is the fifth such post you’ve made, and my answer remains the same - our training material is to help get you through your Foundation exam. We are following the RSGB exam syllabus. You are referring to Intermediate-level information that will be covered when you study for your Intermediate exam.
I was surprised you didn't say what an impedance is, you also said that wavelength affects Impedance, sorry but wavelength has no effect at all on impeadance,if it did we would have coax cable for use on each band which we do not.
Again, may I respectfully refer you to the RSGB exam specification (section 4C6). We are teaching required knowledge to help you to get your Foundation licence Clive.