How badly can high Local Ambient QRM affect HF Radio?

Effects of Local Ambient QRM on HF Radio Local ambient QRM (Noise) from various electrical appliances and other sources in the neighborhood often adversely affect HF radio communication. The negative effects of local QRM on an HF amateur radio station’s overall capabilities are usually far more pronounced than what most operators realize. The ability to address these noise issues may either make or break the radio station’s DX coverage efficacy. In the modern day-n-age, radio amateurs who live especially in urban and suburban areas are plagued with these adverse effects with several orders of magnitude greater nuisance value than the old-timers who operated several decades ago. Although these problems could be mitigated to a large extent by carefully choosing and setting up the antenna system, the unfortunate fact is that many radio amateurs do not even realize how or why these factors affect the radio station performance. The usual trend is to set up the antenna, use a low-loss coaxial cable which has become a fad these days, adjust the SWR to as low as possible either directly or using... Click Here to Read Full Article […]

A Typical 40m HF Band Opening – A Graphical Rendition

40m HF band opening – Animated view Here is an animated graphical rendition of a typical 40m HF band opening transition scenario that I have modeled to provide a pictorial insight into the process. Any animated graphical rendering of HF band propagation opening as it gradually unfurls with the passage of time over the global canvas is a treat to watch. We all know that as a band opening begins to occur, the radio propagation prospects into distant land begin to unfold. This is a gradual process and is primarily dependent on the rotation of the earth on its axis leading to a change in illumination of the globe by solar radiation. As we daily progress through the diurnal (day/night) variation, we expect these changes to play out. On account of the above phenomena, the plasma density of the ionospheric layers above the earth also continuously alters their characteristics in terms of their charge densities, thickness, and height. During the night, the D-layer dissipates while the E-layer practically disappears due to excessive thinning of its plasma density. The F1 and... Click Here to Read Full Article […]

Antenna

Good Antenna for any Radio Station is vital The importance of antennas for radio communications can never be over-emphasized. A radio station is as good or as bad as the antenna it has. Functioning as an efficient radiator while transmitting and as an efficient receptor while receiving are the primary objectives. The performance and behavior of antennas can be tailored in innumerable ways. The radiation pattern of antennas can be molded to control the gain, directivity and coverage area. There are two basic types of antennas, the standing-wave and traveling-wave antenna. All antenna systems are developed around either of these two types. Complex structures are an extension of the basic doublet. Most antennas are resonant, however non-resonant designs are also common. Radiating elements can be oriented vertically, horizontally or obliquely depending on the design. The elements can be extended in multiples of the fractional wavelength. Multiple elements can be placed within the near-field of the primary driven radiator to shape radiation patterns. These elements can either be parasitically driven by drawing energy from the primary radiator as in the Yagi-Uda... Click Here to Read Full Article […]

Why might Antenna Height matter more than Gain

Does antenna height matter more than gain? Though it may seem to be paradoxical at first sight, the fact is that very often the antenna height above ground might matter more than its published gain when it comes to HF band antennas used for DX operation. Long-range DX contacts on HF bands typically require long skips on optimally selected frequency bands for best results. To achieve this objective, the radiation takeoff angle (TOA) has to be quite low. Especially, under low SSN conditions (as is prevalent at the time of writing this post), when the ionospheric plasma densities are low and the slab thickness is also less, the higher TOA signals might penetrate the ionosphere to be lost in outer space. Low TOA signals from the antenna provide us the best prospects. Does this mean that we need to search for some special kind of antenna with low TOA capability to deploy at our QTH? NO! We don’t… Every antenna can be installed in a manner so as to provide low TOA, however, the user must be aware of how... Click Here to Read Full Article […]

Learn CW Morse Code – Lesson Set 1

Learn CW Morse Code – Lesson Set 1 This article on Learn CW Morse Code – Lesson Set 1 is the first in our series of lesson sets for beginners and perhaps others too, to learn Morse code on the journey to becoming a proficient CW Radiotelegraphy operator. Throughout these several sets of lessons that I present on this website, I will walk you through a scientific process for learning Morse code most efficiently. Unlike other methods that are often advocated, this set of lessons will not only allow you to attain proficiency in copying Morse code by the ear like a professional but will also allow you to copy it without hitting a speed barrier. After you train yourself by following the tutorial sequence, you will discover that Morse code is rather easy, charming, and quite musical… It is like any other regular language but with a very small vocabulary thus making it pretty simple. Of course, initially, you might find the Morse code character sounds a bit alien, however, once you cross the initial barrier, it will turn... Click Here to Read Full Article […]

The Great Circle Map – GCM

The Great Circle Map – GCM We present an automatically rendered Great Circle Map – GCM based on your location derived from your Internet IP address. Therefore the Great Circle Map generated below should be accurate and relevant to your physical location (QTH). This map is an alternative to the Antenna Bearings Rectangular Map presented on another page of this website. This GCM projection provides a far more accurate alternative perspective. However, beware that if you are using a VPN to access this website, then the map rendering will be based on the IP location of your VPN and not your actual location. Your current location for which the Great Circle Map is rendered is given below… Latitude:        Longitude: When this webpage was loaded the original IP-derived Latitude and Longitude was used to render the Great Circle Map for the Grid Square location as a default. Normally, the map center accuracy should be more than adequate for HF radio DX communication purposes. However, if wish to generate GCM for any other Grid Square location, you may enter a properly... Click Here to Read Full Article […]

Skip Zone – HF

Beware of Skip Zone while working HF radio A good radio amateur friend of mine from Poland sounded quite anxious when he told me that his new antenna was behaving peculiarly. He was afraid that being a restricted-size vertical antenna perhaps it was not performing as it should. He asked for my views. After speaking to him I realized that there was nothing wrong with the antenna but the problem was entirely different. The issue that my friend was facing was a typical ionospheric skip zone situation. Although on the 20m band, he could work stations in Moscow, and various parts of Italy, and Spain which are all quite a distance away, he was unable to copy or work into nearby countries like Germany, Netherlands, Czech Republic, etc. I soon realized that in his hurry he had completely forgotten to account for the prevailing “Skip Zone” around his QTH. All of us make such mistakes and then scratch our heads over inexplicable results. For those who would like to visualize what was happening on the 20m band from the location... Click Here to Read Full Article […]

HF Long Path (LP) – Quick tips and pointers

HF Long Path (LP) – Getting acquainted HF radio DXing may often be leveraged by the use of HF Long Path (LP) from time to time. By and large, on a routine basis, we all tend to explore HF radio propagation openings that prevail along the better known Short-Path (SP). The earth is nearly a spherical object and the path taken by the radio signals to travel to the DX location is always via the shortest straight path along the spherical surface of the globe. However, this straight path if extended beyond the DX location eventually circles the globe and reaches back to the originating TX station’s location. This is the full Great Circle path. The Great Circle round-the-world path is always unique between any two radio stations on earth. In one direction along the circular path (Great Circle), the distance is shorter than the distance along the opposite direction. The direction along the shorter of the two distances is called the Short Path heading, while that in the opposite direction is the Long Path heading. There is only one... Click Here to Read Full Article […]

Antenna Bearings – Geodesic Map

Antenna Bearings – Geodesic Map We present automatically rendered Antenna Bearings with Geodesic Paths projected on a Rectangular Map. Each geodesic great circle path displayed on the map originates from your location that is derived from your Internet IP address. Therefore the Antenna Bearing Geodesic Map generated below should be accurate and relevant to your physical location (QTH). This map is an alternative to the Great circle Map presented on another page of this website and hence provides an alternative perspective. However, beware that if you are using a VPN to access this website, then the map rendering will be based on the IP location of your VPN and not your actual location. Your current location for which the Antenna Bearing Geodesic Map is rendered is given below… Latitude:        Longitude: When this webpage was loaded the original IP-derived Latitude and Longitude was used to render the Antenna Bearings Map for the Grid Square location as a default. Normally, the map center accuracy should be more than adequate for HF radio DX communication purposes. However, if you wish to generate... Click Here to Read Full Article […]

State of Western Economy

State of Western Economy Starting in the year 2020, the economies of the world came under pressure, especially the western economy. This was caused due to various unforeseen global events that followed one after another. The turmoil started with the Covid-19 pandemic that hit the world. Two years later it was followed by the Ukraine-Russia conflict. The cascade effect of all these factors resulted in economic troubles. Although the entire world was adversely affected, greater disruptions were experienced by the western economy comprising mainly of the trans-Atlantic nations. These nations of the developed world mainly comprised of the USA, the UK, and the nations of Europe. The reason for the high magnitude of economic disruption experienced by the western economy was among other factors largely exacerbated due to carelessness and fiscal indiscipline. During the Covid-19 pandemic period, while a large number of bigger economies of the global south exercised adequate fiscal prudence, the nations of the collective west resorted to imprudent fiscal measures like large and indiscriminate stimulus cash distribution among its people. They were reckless in opting for huge... Click Here to Read Full Article […]