27-09-2018, 05:48 PM
(27-09-2018, 02:10 PM)VK4ADC Wrote: It doesn't stop you from getting a dipole (or other antenna) ready provided you only use an impedance bridge to tune it. Just no transmitters allowed - yet !!!
We already know what the centre frequency will be because of " the word-wide allocation of 5351.5 to 5366.5 kHz to the Amateur Service on a secondary basis " gives 5360KHz to tune to but the SWR bandwidth / tuning will be fairly broad so that an approximation is all that is required.
I plan to add a 60M section to my multiband 80 / 40 /30 dipole set as that will be fairly simple. I suspect I would run into tuning issues if I added it to my 160 / 80 / 40 /30 dipole set due to ' near' 1 and 1/2 wavelength actions from the full-size 160 metres section (CF=1830, 3x = 5490) - then again it may already give a reasonable SWR at 5360 but I can't try it. Maybe the 130KHz shift will be too far to be an issue in terms of tuning interaction.
Must have a listen across that band occasionally and see what I can hear internationally ....
5 MHz is widely used in PNG for health services communication because propagation is very good in that type of terrain and a jungle environment - something that was found out during WW2 when the Australians tried to use portable radios tuning 6-8 MHz with very poor results. The Japanese, who already had radio experience in a similar situation mainly stuck to 3-6 MHz.
If I listen around 5.5-5.8 MHz in the late afternoons I can easily hear some of the health nets I was using when I worked in PNG in the 1980's and 1990's. After sunset the band is swamped by Asians.
If we do get access to 60 Metres we will have to be very careful not to interfere with "safety of life" communications in our northern neighbors. Low-power data comms should be OK.
73
Wayne VK4WDM