DEAR WORLD RADIO AMATEURS - DUE TO THE MASSIVE EARTHQUAKES IN TURKEY, 28.540 MHZ (USB) FREQUENCY HAS BEEN DETERMINED AS A DISASTER COMMUNICATION FREQUENCY
PLEASE DO NOT BUSY THIS FREQUENCY 73 TA1XX
A 7.8 Magnitude earthquake hit Türkiye and Syria at 01:17UTC on 6th February leading to a large loss of life and many casualties. Aftershocks continue in the area with another large 7.5 magnitude event happening at 10:24UTC affecting the response.
The emergency communications group of TRAC will be involved in the response activities, primarily expected to be on VHF/UHF but they do also use 3.777 and 7.092MHz as needed.
Radio Amateurs are requested to give way to any emergency traffic around those frequencies.
My thoughts go out to the casualties, relatives and friends.
Cycle 25 is doing very well. It is going up considerably, more than expected. We are now at the level of 9 years ago. This afternoon I was spotted by ZL4DC, my 200 mW WSPR signal on 20 meters, report SNR -18 dB. A distance of 18740 km / 11640 miles. That's 93700 km/watt.
The blue line is 30 meters, the red line is 20 meters
DX contact with Steve / SM4OTI using a 20-W Xiegu G90 and a Half-Square (phased 1/4 verticals) antenna on the 15 meter ham band. 73 Lynn NG9D. The Xiegu is a nice compact little low power / QRP transceiver. It’s made in China. What strikes me about CW videos is that the communication is extremely efficient. FT8 can't match that. (video by NG9D)
Antenna construction information follows:
This antenna is two 1/4 wavelength verticals, spaced one half wavelength, fed in phase by the top wire. The current maximums are at the top corners. The coax feed point is at one top corner. The theoretical gain over a single vertical is 3.8 dB (ref: ARRL Antenna Book).
An important advantage of this antenna is that it does not require the extensive ground system and feed arrangements that a conventional pair of quarter wavelength verticals would require. The bidirectional pattern is broadside to the verticals.
Self-supporting 15m phased verticals (without any need for a grounding system or radials) “Half-Square Antenna”
PARTS LIST:
1. Two steel fence posts, 4’-0 long
2. Two 1.5 inch diameter schedule 40 PVC pipes, 5 ft long
3. Two 12’-0 telescopic aluminum painter's poles
4. Six stainless steel hose clamps, 9/16 - 1-1/16”
5. 14 ga insulated copper wire, 25’-0
6. Insulator
7. 50 or 75 ohm coaxial cable RG-58 or RG-59
8. Coax connector
LAYOUT:
Total conductor length, verticals plus top horizontal wire, is one wavelength.
Length of each vertical 1/4 wavelength.
Length of top horizontal wire 1/2 wavelength.
Location of low impedance feed point: upper corner.
NOTE:
Sand oxide from aluminum tube at connectors.
Use jumper wire at telescopic joint for electrical continuity.
Use PVC tube as sleeve over the fence post to hold the aluminum pole.
Use plastic handle of painter pole as bottom insulator,
resting on the top of the steel fence post. Self-supporting 15m phased verticals (without any need for a grounding system or radials) “Half-Square Antenna.”
