Tag Archives: Antenna

February goes out with a bang

Listening conditions for a large chunk of the Winter Period (here in the Northern Hemisphere) have been plagued with noise and low MUF (Maximum Usable Frequency). This has been caused, in part, to a somewhat disturbed Sun. Even though we are in the descending part of the current cycle, CME’s and other perturbations can still occur.

However, over the last week or so, Old Sol has quietened down enabling a number of stations, not heard here for a while, to be logged once again. I noticed that South American stations have started to become audible earlier. Radio Bahrain, which is only a 10 KW transmitter and usually inaudible for most of the year, was logged on the 28th. Fairly deep down in the noise, but audible nonetheless.

Some I’m looking forward to some better weather as we move into spring, to enable me to repair my antenna which the autumn gales slightly trashed. I am also looking forward to getting out and about with a newly acquired Tecsun PL-310ET. This diminutive can pack a punch when connected to an external antenna, but can overload. So I want to get it away from all the urban RFI and see how it performs. I will report on this at a later date. So here’s to spring and summer and good DXing.

Stations logged on the last day of February:

9335 Khz Phillipines VOA 16:21 UTC Burmese. Discussion SINPO: 33223 2017-02-28

9355 Khz Thailand VOA Deewa Radio 16:27 UTC Pashto. Discussion. Horrible over-modulation. SINPO: 54344 2017-02-28

9390 Khz Thailand RFE 16:30 UTC Uzbek. ID and schedules at 16:30. SINPO: 44444 2017-02-28

9405 Khz Taiwan R Taiwan Intl. 16:33 UTC Traditional music and chat in English. ID at 16:40 SINPO: 32222 2017-02-28

9525 Khz Java V O Indonesia 17:12 UTC Spanish. Discussion with male announcer.ID at 17:15 SINPO: 44444 2017-02-28

9730 Khz Vietnam V O Vietnam 17:19 UTC Vietnamese. YL announcer. SINPO: 43333 2017-02-28

9745 Khz Bahrain R Bahrain. 17:22 UTC Arabic. OM announcer just audible. Some music at 17:24 SINPO: 22112 2017-02-28

9810 Khz Singapore BBCWS 17:26 UTC Dari. Closing announcements and back-ground music. SINPO: 54444 2017-02-28

9835 Khz Malaysia RTM Sarawak 17:30 UTC Music. SINPO: 22222 2017-02-28

9390 Khz Thailand R Thailand 19:00 UTC English. News and current affairs on The Morning Program SINPO: 54455 2017-02-28

9985 Khz Thailand VOA 19:10 UTC Korean. Music and chat SINPO: 43333 2017-02-28

 

The true story of the Yagi Antenna

From the DXZONE comes this interesting article on the development of the Yagi antenna.

Yagi antenna history

As many of you may already know, the full name of this antenna is Yagi-Uda Antenna.

The origin of this name is derived by the surname of two Japanese inventors that designed this antenna for the first time at the beginning of the 1920’s.

Yagi Antenna US Paten
Yagi Antenna US Patent Source http://www.uspto.gov
The two inventors were, Hidetsugu Yagi(1886-1976) and Shintaro Uda (1896-1976)  both professors at the Tohoku University Japan.

What not everyone knows is that the original concept of this antenna has to be attributed to Shintaro Uda(Yagi’s assistant professor) that in 1926, first described this antenna at Tohuku University in Japan,  in the IEEJ (Japan).

Hidetsugu Yagi , who worked in the UK, USA and Germany, applied for patents on the new antenna both in Japan and the United States.

The Japanese patent was immediately issued in 1926 with nr. 69115 while the U.S. patent 1,860,123filed in 1926 was issued later in 1932.

While the Japanese patent was properly attributed to both the inventors, the US patent was assigned tothe Dr. Yagi.

Japanes Patent 69115
Japanes Patent 69115 source aktuellum.com

Dr. Yagi is listed among the ten Japanese great inventors by the Japan Patent Office for this very invention, and has been president of Japan Amateur Radio League (JARL) in 1946.

Although no one can ever tell us how much authorship should be attribute to Professor Yagi rather than Professor Uda , certainly we should attribute the right authorship to this antenna by naming it always as Yagi-Uda.

Poor HF conditions…or is it me

I am not sure if it is just my location, not-too-hot antenna, poor hf conditions or a combination of all of these, but I don’t seem to be able to hear much in the way of DX or even interesting stations at the moment. I have tried on a few occasions to log Global24, which shouldn’t be too difficult, but I haven’t managed it yet.

I do have a design for a new antenna which I shall try when weather conditions and time allow. It is actually featured in an article by AC0LW Dan Farber, in this months Spectrum Monitor magazine. It is a vertical Zepp. It takes the idea of the traditional Zepp antenna, fed at one end with open-wire feeder, and turns it into a vertical fed with open wire feeder. Dan says he has had good results with only a 37 foot length for the vertical section. In my case, I am planning on using 66 foot length, but not all this will be vertical! It will be about 26′ vertical, with the rest sloping away to be tied off at my back fence. It is an easy build, and more importantly for me, an easy installation (not too good up ladders these days!) as I have a pole at the side of the house from a previous antenna installation. Hopefully, when I get this installed, I shall report back findings.

If you have not looked at it before it is worth thinking about a subscription to The Spectrum Monitor. It is a replacement for the old Monitoring Times, which I never took. Each month there is a good mix of articles covering all aspects of radio monitoring, be it SWL, Amateur, Military, Utility etc. Individual mags. cane be purchased from the website at: http://www.thespectrummonitor.com/

Going back to HF propagation, I found this handy tool, linked from G0KYA’s website. Although designed for amateur bands usage, it is a handy tool for all SW listeners. See: http://www.infotechcomms.net/propcharts/november/