Originally Posted by big420dog94550
I was wondering how I would check the ohms reading at the coax connection point on a Antenna that I built that I am only using as a Receiving Antenna and not a Transmitting Antenna without a SWR meter? Does the ohms there make a difference?
Does resistance make a difference or not? Yes it does, but its' worth pointing out that when it comes to undertaking antenna measurements there is a lot more to "Ohms" than we normally associate with this measurement.
To start with we dealing with an measurement taking almost exclusively on a sinusoidal wave, which will vary constantly depending on the point at which its taken from on the antenna element, and the time its taking at i.e. a reading other than 50 Ohms does not mean an antenna is not resonant ...... and then things get more complicated ........!
To add to what W2NJS has contributed, antenna measurement is a science all on its own, which, to undertake requires a whole bunch of instruments. Noise bridges are great pieces of kit to have (and as W2NJS has said, are precision instruments and not cheap), a simple SWR meter is also great to have, and so are things like vector analyzers to undertake things like S-Parameter tests, and these too are big big buck pieces of hardware but are essential to properly measure and characterise antenna performance
Read the following online article.
Impedance of an Antenna
There are hundreds on-line like it if you type in to Google "antenna impedance"