My Slide Pages

19 Nov 2010

Welcome Solar Cycle 24


Solar Cycle

The solar cycle, or the solar magnetic activity cycle, is the main source of the ~10.7 year periodic solar variation (changing the level of irradiation experienced on Earth) which drives variations in space weather and to some degree weather on the ground and possibly climate change. The cycle is observed by counting the frequency and placement of sunspots visible on the Sun. The basic causes of the solar variability and solar cycles are still under debate, with some researchers suggesting a link with the tidal forces due to the gas giants Jupiter and Saturn, or due to the solar inertial motion. Another cause of sun spots can be solar jet stream "torsional oscillation".



Effects of the solar cycle


The Sun's magnetic field structures its atmosphere and outer layers all the way through the corona and into the solar wind. Its spatiotemporal variations lead to a host of phenomena collectively known as solar activity. All of solar activity is strongly modulated by the solar magnetic cycle, since the latter serves as the energy source and dynamical engine for the former. Emission from the Sun at centimetric (radio) wavelength is due primarily to coronal plasma trapped in the magnetic fields overlying active regions. The F10.7 index is a measure of the solar radio flux per unit frequency at a wavelength of 10.7 cm, near the peak of the observed solar radio emission. It represents a measure of diffuse, nonradiative heating of the coronal plasma trapped by magnetic fields over active regions, and is an excellent indicator of overall solar activity levels. The solar F10.7 cm record extends back to 1947, and is the longest direct record of solar activity available, other than sunspot-related quantities.

Rendition of Earth's magnetosphere
Source : http://sec.gsfc.nasa.gov/popscise.jpg

Sunspot activity has a major effect on long distance radio communications particularly on the shortwave bands although medium wave and low VHF frequencies are also affected. High levels of sunspot activity lead to improved signal propagation on higher frequency bands, although they also increase the levels of solar noise and ionospheric disturbances. These effects are caused by impact of the increased level of solar radiation on the ionosphere. It has been proposed that 10.7 cm solar flux can interfere with point-to-point terrestrial communications.

The following is a list of solar cycles (sometimes called sunspot cycles), tracked since 1755

The impact of solar cycle on living organisms has been investigated. Some researchers claim to have found connections with human health. The amount of UVB light at 300 nm reaching the Earth varies by as much as 400% over the solar cycle due to variations in the protective ozone layer. In the stratosphere, ozone is continuously regenerated by the splitting of O2 molecules by ultraviolet light. During a solar minimum, the decrease in ultraviolet light received from the Sun leads to a decrease in the concentration of ozone, allowing increased UVB to penetrate to the Earth's surface. The sunspot cycle has been implicated in having effects on climate, and may play a part in determining global temperature.


Skywave modes of radio communication operate by bending (refracting) radio waves (electromagnetic radiation) off of the Ionosphere. During the "peaks" of the solar cycle, the ionosphere becomes ionized by solar photons and cosmic rays. This affects the path (propagation) of the radio wave in complex ways which can both facilitate or hinder local and long distance communications. Forecasting of skywave modes is of considerable interest to commercial marine and aircraft communications, amateur radio operators, and shortwave broadcasters. These users utilize frequencies within the High Frequency or 'HF' radio spectrum which are most affected by these solar and ionospheric variances. Changes in solar output affect the maximum usable frequency, a limit on the highest frequency usable for communications.

References : Wikipedia & Youtube

12 Nov 2010

9w2esm - FAQ about QSL card


What is QSL card?
QSL is one of the Q codes used in radio communication and radio broadcasting. In this case, QSL means either "do you confirm receipt of my transmission?" or "I confirm receipt of your transmission". A QSL card is a written confirmation.

What is green stamp or GS?
Green stamps were actually U.S. Dollar money to help avenger QSL card in terms of shipping and so forth. 2 GS means 2 USD required.

What is SASE or SAE?
SASE or SAE is a Self Address Envelope stamped (without stamp), usually used with GS and QSL cards.

How to know the recipient address?
In this era of IT technology, almost most ham using internet facilities to see the address of the station that they call. One of the most popular web sites is qrz.com. There is also a ham that put their address on their web site and there is also informed directly when on the air. In addition, the services of buro or bureau can also be used.

What is QSL buro or bureau?
Sending QSL cards directly to a distant station is most often fastest, the confirmation of large numbers of international contacts may prove expensive. An alternative offered by many national and regional amateur radio societies is a bureau system. QSL's from individual stations are sent to an outgoing bureau locally; that bureau bundles all outgoing cards for each country and sends each bundle as a single package - reducing international postage costs. At destination, a national or regional incoming bureau holds received cards so that they may be claimed by the operator of the intended station.

What is QSL manager?
QSL manager is the person who manages the receiving and delivery services for the QSL cards for hams that require its services to all log entry, whether new or old. QSL manager is usually used for the DXpedition activity.

What is IRC?
An international reply coupon (IRC) is a coupon that can be exchanged for one or more postage stamps representing the minimum postage for an unregistered priority airmail letter of up to twenty grams sent to another Universal Postal Union (UPU) member country. IRCs are accepted by all UPU member countries.

What is QSL card format?
QSL card contains details about one or more contacts, the station and its operator. At a minimum, this includes the call sign of both stations participating in the contact, the time and date when it occurred (usually in UTC), the radio frequency or Band used, the mode of transmission used, and a signal report. The ARRL recommends a size of 3½ by 5½ inches (89 mm by 140 mm). QSL cards frequently includes an expression of individual creativity from a photo of the operator at his station to original artwork, images of the operator's home town or surrounding countryside, etc.

What is eQSL?
eQSL, or electronic QSL, is an online system where amateurs can leave confirmation of their contacts for other participants without the necessity of mailing a hard copy, thus saving the expense associated with mailing, especially overseas. Be advised that eQSL can generally not be used for awards, and many hams to not accept or wish to participate in this system. Example the site is www.eqsl.cc/qslcard/Index.cfm. eQSL does in fact have a verification process called Authenticated Guaranteed (AG) and has its own eAwards program. Electronic QSL card also can be done by exchange the QSL card through the email and etc.

What is LOTW?
LOTW, or Logbook of the World, is a system operated by the ARRL where users from around the world can submit records of their contacts. When both participants in a QSO submit matching QSO records to LoTW, the result is a QSL that can be used for ARRL award credit. This is because LOTW is tightly controlled to verify submissions. All QSO records are digitally signed using a certificate obtained from ARRL. Obtaining such a certificate requires verification of the licensee's identity either through mail verification (US) or inspection by ARRL of required documentation (non-US).

What Can I Do With All These QSLs?
Now that you have a collection of QSLs, there are many things that you can do. It is human nature to catalog anything of quantity into a database. It is also human nature to compete. Welcome to the world of awards! There are many awards. One of the most popular is the ARRL's DX Century Club, also known as DXCC (collect QSLs from 100 different countries).

*All FAQs is my point of view - please refer to your elmers or your own amateur radio society club