However if you do this I cannot guarantee it will work as well as a transformer made with the specified parts. Here is can be easily accommodated on vehicles for applications like PMR or even amateur radio. Easy installation makes it great for portable, temporary uses like field day, DXpeditions, etc. Note that all of these 'easy to match' antennas work in more or less the same way by incorporating resistive loss into the matching transformer, or by adding external resistors such as the Diamond BB7V and BB6W. Your email address will not be published. Skip to content Loading
If some additional loss through the transformer and approx 2dB loss through coax cable is factored in, and the radiating element and radial system are fine tuned, it is possible to achieve a VSWR of less than 2: The exact amount of power that will be radiated will depend upon the antenna wire feed impedance at a particular frequency, but it is likely to radiate more power when the antenna feed impedance is lower than the the value of load resistance. It provides a useful amount of gain for an increase in size that can often be accommodated with no issues. They are not too critical, for example, three 5m long radials would be fine, however I would suggest that all the radials or counterpoise wires and the mounting pole are not connected to ground and the length does not exceed 10m. Actually, experience tells me that the real resonant frequency will be a little higher. This calculator is designed to give the vertical length height of a particular antenna, for the frequency and wavelength chosen.
6 Meter Antenna | eBay
There is a very large variation between types even those from the same make and model I think they just use whatever they can get hold of. Following its publication, I was awarded the RSGB Bennett Prize in recognition of a 'significant contribution or innovation which furthers the art of radio communication'. This is usually the maximum SWR most radios can withstand without the SWR protection operating to reduce the output power to a safe level. Cut down your exam stress by using our latest pmp training certkiller and high quality examsheets gmat practice questions and braindumps scjp dumps. I have tried a large selection of ferrite materials, including some which I have recovered from scrap CRT PC monitors. The input impedance with no radiating element connected should measure at least ohms at the lowest operating frequency. Again, this calculator is courtesy of N2IMF
I could be available to come and teach a one-day Tech class for your club or organization, though. Unfortunately some of the ferrite rings I have bought recently are slightly smaller, and so will not fit over standard size copper water pipe. You should carefully design the feedpoint mechanics for strength. It took few days to get the pictures done because we were entirely sold out on just about everything! The red vector is the antenna impedance, green is the inductor impedance, and blue is the sum of both. On the HF bands adding a remote atu made very little difference. The vertical itself can be made of a piece of wire along a fibre mast.