Now is a good time to think about antennas for 6 metres or 50 MHz, particularly if you're in the northern hemisphere. Because there it's summer and that's when sporadic-E propagation peaks. After months of being dead this is when 50 MHz comes alive with strong signals easily workable with low power. Provided you live in an area with lots of hams in a 500 to 2500 km distance you too can makes lots of contacts as these are the distances most optimum for sporadic-E propagation.
I often get asked whether antenna polarisation is important. It depends. For local communication, such as via 6m FM repeaters (which exist in some countries) it is. If you don't use vertical then your transmitting range will be much less. Whereas for longer distance propagation involving the ionosphere (where signals bounce around) polarisation isn't important. So you can easily use a vertical dipole to talk to stations with horizontal beams and you won't be disadvantaged.
Dipoles and verticals are fine for stations interested in casual sporadic-E contacts. If you want to go after multi-hop contacts or have success under more challenging conditions then you will need a gain antenna such as a beam. The 4 MHz width of the band (in the USA and Australia) is another factor as an antenna for 50 MHz won't perform so well at 54 MHz. If you're a dedicated 6 metre operator you will probably want a horizontally polarised beam for 50 MHz SSB activity and some sort of ground plane or vertical dipole optimised for FM around 53 MHz.
Anyway, here are some practical antenna ideas that will get you going on 50 MHz.
* Wire dipole for 28 and 50 MHz (use inner section only if 50 MHz only is desired)
* Pedestrian mobile magnetic loop (for upper HF and 50 MHz)
* Quick and dirty half wavelength wire vertical antenna for 50 MHz
* DK7ZB 50 MHz yagis
* K1BQT lightweight 50 MHz yagi (pdf)
* OH1TV 2 element phased array for 50 MHz (pdf)
PS: Want to get the most from low power amateur radio? You need Minimum QRP. It covers the equipment, antennas, operating and strategy you need to succeed with QRP. It's available as an ebook or paperback and has been favourably reviewed.
I often get asked whether antenna polarisation is important. It depends. For local communication, such as via 6m FM repeaters (which exist in some countries) it is. If you don't use vertical then your transmitting range will be much less. Whereas for longer distance propagation involving the ionosphere (where signals bounce around) polarisation isn't important. So you can easily use a vertical dipole to talk to stations with horizontal beams and you won't be disadvantaged.
Dipoles and verticals are fine for stations interested in casual sporadic-E contacts. If you want to go after multi-hop contacts or have success under more challenging conditions then you will need a gain antenna such as a beam. The 4 MHz width of the band (in the USA and Australia) is another factor as an antenna for 50 MHz won't perform so well at 54 MHz. If you're a dedicated 6 metre operator you will probably want a horizontally polarised beam for 50 MHz SSB activity and some sort of ground plane or vertical dipole optimised for FM around 53 MHz.
Anyway, here are some practical antenna ideas that will get you going on 50 MHz.
* Wire dipole for 28 and 50 MHz (use inner section only if 50 MHz only is desired)
* Pedestrian mobile magnetic loop (for upper HF and 50 MHz)
* Quick and dirty half wavelength wire vertical antenna for 50 MHz
* K1BQT lightweight 50 MHz yagi (pdf)
* OH1TV 2 element phased array for 50 MHz (pdf)
PS: Want to get the most from low power amateur radio? You need Minimum QRP. It covers the equipment, antennas, operating and strategy you need to succeed with QRP. It's available as an ebook or paperback and has been favourably reviewed.
No comments:
Post a Comment