This tool calculates the antenna capacitance and radiation resistance of small vertical monopoles at 475 kHz. It is by no means a replacement for antenna design software such as EZNEC, but should give a clue how the antenna will perform.
Following limitations apply:
- Total dimension (H+L) less than 15% of the wavelength (= less than 95 m)
- Wire or small tube construction (less than 2.5 cm)
- The calculations assume an unobstructed antenna. Object near or under the antenna will reduce the radiation resistance and increase the antenna capacitance.
Photo: W7RN This is a comprehensive intro to the PSK31 digital mode. It’s all of the major concepts and some demonstration crammed into a 30 min... Read more
KD0CQ has recently been experimenting with trying to receive signals at frequencies of up to 4.5 GHz with an RTL-SDR and downconverter. Since a typica... Read more