CQ 80 meters
At my sunset, in the next few hours, I am going to be looking for my ham buddy 2E0KXD on the other side of the Atlantic, to see whether or not we can make a contact with his GAP antenna on 80 meters. I know that in times past before the sun drops over my horizon in the West I can drop an R5S9 signal into Europe. After the sun sinks over the horizon some signal improvement to S9+20 is the norm. Most time signals are stronger on my receiver, but I find that most EU hams may be transmitting at their legal limit. I have not found any reason to go to my legal limit here as yet.
I have not used my 80-meter antenna for a while and had to effect some emergency repairs to be ready for tonight. My antenna is positioned above my chain link fence. The parasitic vines running on the fence always project appendages to entangle the bottom loading wire running parallel to the fence at a height of about 1-foot above it. Above the perimeter fence seems like the most unobtrusive place to place a top and bottom load vertical dipole. Unfortunately, some hams in some countries can't do that, but for those of us who can, we should not miss the opportunity.
Last week I experimented with using one guy wire to tie off the top and bottom load wire, but that seems to have a negative impact on the bandwidth as the tips of the loading wires became closer to each other. I am now looking at two 20-foot supports for guying and holding the top load wires higher above ground. I suspect that this would improve the bandwidth. My present band spread for an SWR of 1.5 is from 3.7764 MHz to 3.867 MHz. or 103 kHz. For an SWR of 2.0 it is from 3.729 MHz to 3.905 MHz or 176 kHz.
These figures indicate that my antenna require retuning to reposition the minimum SWR point from 3.816 MHz to 3.795 MHz, and a piece of antenna wire 16 inches long added to the top or bottom loading wire should do the trick. For minimum stress and ease I make all adjustments on the bottom load wire only, and I am not getting bent out of shape over the shift in feed point impedance. If the sun cools down any I may just drop the bottom wire and add the 16 inches before sunset.
For now let me enjoy what's left of Father's Day.
I have not used my 80-meter antenna for a while and had to effect some emergency repairs to be ready for tonight. My antenna is positioned above my chain link fence. The parasitic vines running on the fence always project appendages to entangle the bottom loading wire running parallel to the fence at a height of about 1-foot above it. Above the perimeter fence seems like the most unobtrusive place to place a top and bottom load vertical dipole. Unfortunately, some hams in some countries can't do that, but for those of us who can, we should not miss the opportunity.
Last week I experimented with using one guy wire to tie off the top and bottom load wire, but that seems to have a negative impact on the bandwidth as the tips of the loading wires became closer to each other. I am now looking at two 20-foot supports for guying and holding the top load wires higher above ground. I suspect that this would improve the bandwidth. My present band spread for an SWR of 1.5 is from 3.7764 MHz to 3.867 MHz. or 103 kHz. For an SWR of 2.0 it is from 3.729 MHz to 3.905 MHz or 176 kHz.
These figures indicate that my antenna require retuning to reposition the minimum SWR point from 3.816 MHz to 3.795 MHz, and a piece of antenna wire 16 inches long added to the top or bottom loading wire should do the trick. For minimum stress and ease I make all adjustments on the bottom load wire only, and I am not getting bent out of shape over the shift in feed point impedance. If the sun cools down any I may just drop the bottom wire and add the 16 inches before sunset.
For now let me enjoy what's left of Father's Day.
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