Well before sunset the band was noisy even though the closest storms were 250 miles to the South here in Texas. Ken, K5DNL / WG2XXM, reported S9 noise when he began transmitting and SWL Ken in Indiana noted a noisy start for him as storms approached from the West. A quick check of the band at bed time suggested that the noise was not a constant roar but individual lightning strikes so the band was probably going to be serviceable.
As we have a lot of newer stations coming on line here is some advice: We are moving into summer-type conditions and many of us have different operating schedules and habits from Winter so don’t get discouraged if a random CQ does not yield a QSO. Even during the Winter its best to schedule or at least notify other ops of you intended activity. The most active ops can usually be found in the ON4KST chat/logger and while you might not get an immediate response to a question or posting depending on time of day. its a good place to “billboard” your activities. Another good place in North America is to sign up for the 600-meter research group email reflector and post your intentions there but understand that email can be slow and may not be seen while you are operating so send your message early.
Geomagnetic activity was elevated through the early part of the session, with solar wind velocities in excess of 500 km/s but the North-pointing Bz helped shield the ionosphere from much of the impacting particles during several periods.
Neil, W0YSE/7 / WG2XSV, reports cold terrestrial weather and increased base current. You have no idea how much I envy both as we approach the upper 80’s F here in Texas. Neil provided these comments and statistics for the session:
Terry, W8ARE / WI2XHK, received very good reports on his second session of activity at 100 mW ERP. Imagine what his reports would be like if the band were quiet! Terry received CW levels reports from Andy, KU4XR, who is using the tree-tenna for receive.
Al, K2BLA / WI2XBV, provided some comments about Terry’s fake ornamental rock used to conceal his ATU from his HOA and provided a link to an article that he, “The Old Professor”, wrote about antennas, their importance, and their concealment in the past and today in his local IEEE journal found here starting on page 4. Al notes that there are probably 30 – 40 articles written by him on the Dayton IEEE section “Sparks” journal, which can be found here.
Phil, VE3CIQ, reports that he decoded NO3M, WG2XIQ, WG2XJM, WG2XKA, WG2XXM, WH2XZO, WI2XHK and was decoded by KU4XR, NO3M, SWL/K9, VE2PEP, WA3TTS/2, WG2XJM, WG2XKA, WH2XZO, WI2XFI, WI2XFO.
Ken, K5DNL / WG2XXM, reports that he decoded ten WSPR stations and was decoded by thirty unique stations including two reports from VK4YB at 13442 km from Shawnee, Oklahoma. Ken also notes that WI2XBV provided reports of his signal at +7 dB S/N at 1640 km.
Joe, NU6O / WI2XBQ, is back after rebuilding his ATU after fire #2. Inclement weather in his North California QTH has hampered efforts to getting back on the air. Joe noted that Larry, W7IUV / WH2XGP, was +15 dB S/N at 0515z. He also reports that he is operating at .5-watts ERP and continued to be reported by WH2XCR in Hawaii half way through the grey line period. Joe also reported VK4YB during the session:
Regional and continental WSPR breakdowns follow:
There were no reports from the trans-Atlantic or trans-African path. UA0SNV was present during the session but no reports were found in the WSPRnet database.
Eden, ZF1EJ, returned for this session and provided solid reports for stations in the eastern and central portions of the US.
Laurence, KL7L / WE2XPQ, had a pretty good session in Alaska decoding and being decoded by a number of stations in the western portions of North America and Hawaii. KL7L/KH6 also reported VK4YB and will be in Hawaii for another week so watch for reporting to continue.
Merv, K9FD/KH6 / WH2XCR, received a significant number of reports from Australia during the session including two-way reports with VK4YB. John, VK2XGJ, reports that he decoded Merv at sunset in VK and provided his console capture as evidence, detailed below.
In Australia, Phil, VK3ELV, and Roger, VK4YB, received reports from WH2XCR. Merv also shared two-way reports with Roger. Phil received reports from three stations in Japan, including JA3TVF who is receiving Phil for the first time based on my data.
Jim, W5EST, presents a short tutorial entitled, “ANTENNA MODELING SOFTWARE: EXAMPLE HOW TO USE AT 630M”:
“Load/install your selected antenna modeling software. For one example, download EZ-NEC Demo v6.0 free from https://www.eznec.com/demoinfo.htm When you’ve installed it, use the EZ-NEC control buttons per my illustration here, upper left.
Click “Open” to select one of the prestored antenna input data files that come with the program. Open the Vert1 antenna file to get started with 630m transmit antenna modeling. Using the “Frequency” button, establish a 0.4757 MHz frequency. Now click the “Wires” button. Modify the vertical to your desired geometry by specifying 3D coordinates of all conductor ends such as the top center window illustrates. “View Antenna” (middle) shows the antenna you’ve specified so you can check your work. I specified the T-ended inverted-V blogged April 23. Click “Save As” and supply your desired file name to save the customized antenna file you make. Use “Help” to get answers to your questions.
The control buttons deliver antenna displays. “SWR” shows you the antenna’s complex impedance in the SWR plot window, lower left. At 630m the reactance will be so high that the SWR plot is infinite because no ATU is specified so far. That’s ok since we just want R+jX right now. “SWR” helpfully adds red lines to the “View Antenna” display to show the distribution of RF current along the antenna wires.
Be careful interpreting the resistive part of antenna impedance, because the wire size has loss resistance that affects results. To get the radiation resistance, set “Wire Loss” in middle of column to Zero beforehand, as shown.
Click far-field “FF Plot” and “Plot Type” to call for and see azimuth pattern and elevation pattern displays. The azimuth pattern (not shown) gives the front-to-back ratio f/b, which is 1dB or less for many 630m vertical-based antenna geometries. The elevation pattern window, at right, includes a value of dBi, dB gain over the theoretical isotropic radiator.
To rerun the model with wire loss subsequently, first click “Wire Loss” and select the wire metal (copper here). Then repeat, using “SWR,” “FFPlot” and “Plot Type.”
Generally speaking, the good radiation resistance rises as the square of the antenna height, so getting conductors as far “up there” as possible is certainly worth your effort. Radiation resistance also increases when you use longer top hat conductors in whatever geometry. However, since exceptions to that general statement exist, antenna modeling beforehand helps you doublecheck your intuitions.
Tomorrow, I’ll blog the results of modeling runs on a first few antenna geometries and compare them. Stay tuned!”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD <at> gmail dot (com)!