Antennas at my station

Which band for which antenna?

Antennas have a fundamental frequency at which they operate best. This frequency typically occupies one of the bands, but, depending on the design of the antenna, it might also be suitable for other bands.

For each of the antennas we have, these related bands are summarised below. Bands are marked by stars (⭑) describing their suitability for each antenna. Essentially, the more stars the better: ⭑⭑⭑ means the frequency is in band, ⭑⭑ means it is <1% away from the centre of the band, ⭑ means it is <3% away, and ⭒ means it is <10% away. Other bands are just omitted.

Antenna 1 (neon green)

This antenna is about 39m long and its fundamental frequency is therefore around the 80m band, at about 3.65MHz. The half-wave dipole can be operated at a frequency where its length is any odd multiple of half-wavelengths long, namely 10.974MHz, 18.290MHz, and 25.606MHz. These bands are all pretty narrow unfortunately but on the other hand these so-called WARC bands are free of contesters and are therefore a bit more chilled-out. And, of course, you can still use the other bands and play around with the ATU.

Antenna 2 (yellow)

This antenna is about 20m long and its fundamental frequency will be around 7.125MHz. By the same principle, the bands to use with this antenna are:

Exposure

This information is computed from formulae ICNIRP's 2020 guidelines, but please note that at present they don't cover instantaneous exposure or guidelines for incident power density, energy density, induced current, or specific energy absorption rate. We also assume limits are for the general public and not the occupational limits. These figures relate to what is possible to check with the cheap EMF meter we use, though it doesn't measure H-field above 300Hz anyway!

For the 160m band:

For the 80m band:

For the 60m band:

For the 40m band:

For the 30m band:

For the 20m band:

For the 17m band:

For the 15m band:

For the 12m band:

For the 10m band: