These are a rough guide and do not take into account long path openings or sporadic e short path openings in mayaugust. Long path propagation signals can be stronger than short path. A real long path signal will have a significant delay, or echo, since it takes around 0. This site is dedicated to voacap voice of america coverage analysis program for hf propagation prediction and. Dregion absorption prediction from the noaaspace environment center. Propagation maps created with hamcap and based on the predicted smooth sunspot number for the month and cw100w to a dipole at 35ft. Is it correct to apply the logdistance path loss model for an inbody radio propagation. While listening or planning to work a dx station, the radio amateur would like to know what are the current propagation conditions, know if the propagation is open toward a specific location at a specific time, or at what time the band will be open for a specific pointtopoint circuit. The basic concepts behind hf propagation using the ionosphere are easy to understand, and a study of it is not only fascinating, but also very useful for anyone involved in hf radio communications in any way.
Hf propagation conditions of an ionospheric transmission path between two. The color on the top of the ground denotes the ground cover information corresponding to the path. With each hop, bouncing off the earths surface, there is significant signal loss, especially bouncing of land. Whether its going to work depends on a number of varibles. Ace hf is propagation forecasting and modeling for amateur radio as well as for shortwave radio listening and general hf operation. Dx toolbox searches the web for you, gathering information on solar and geomagnetic conditions that affect radio propagation. Distinct long path echo on the stronger short path signals with qsb and qrnm. Short path and long path propagation on hf are widely known phenomenon. Online hf propagation prediction by serge stroobandt, on4aa. This link is listed in our web site directory since monday oct 3 2005, and till today long path propagation has been followed for a total of 2492 times. Freeware realtime, schedule of the transmitting times, frequencies, short path and long path beam headings.
Longpath propagation is the type of propagation that occurs when the longer of the two direct paths between stations is better for communications than the shorter path. In that regard, everyone knows about hf hops from the various regions in the range of 1,5001,750. Uk short path monthly forecast maps radio society of great. Demystifying hf radio propagation and modeling check out the ace hf propagation software the latest is version 2. Apr 05, 2018 chris warren april 5, 2018 april 5, 2018 14 comments on some great propagation calculator websites. The home of the online hf propagation prediction tool, proppy, providing ondemand pointtopoint and area predictions using the itus iturhfprop. Ace animated communications effectiveness provides hf ham radio propagation predictions for the 1. Results are rendered in an easytounderstand colourgraphic display. Rf signals travel at the speed of light, but if the distance is great enough there can be an audible delay between the two signals. Questions tagged propagation amateur radio stack exchange. A situation where hf propagation exists between two stations in the inverse direction of the great circle heading. Advanced users of high frequency hf radio communications have long used systems known as chirpsounders 1 to obtain realtime information about the ionospheric propagation conditions of different communication channels between a transmitter and a receiver.
Jan 02, 2017 as heard by k2rwf mobile on an ic7100 with a shark 20 meter mini hf stick while traveling in northern nj. Ace hf system simulation and visualization software, v2. Richard and sue buckner teamed with joe ahlgren author of geoclock and steve biro to create a dynamic system simulation and visualization software package which uses the voacap propagation prediction engine to create animated maps and charts to help all users of hf radio choose the best times and frequencies for communications. Figs 1 and 2 were generated using the geoclock computer programs. In the frame of longterm hf prediction the iap develops and provides a software package. Voacap voice of america coverage analysis program is free professional highfrequency hf propagation prediction software from ntiaits, originally developed for voice of america voa. I did measurements with bioequivalent liquid and got a plot of the path loss over distance. Long and shortterm prediction of hf radio propagation research. Voaprop was written to satisfy my need for a program that would show me what hf band propagation should be like on a particular day on a particular band. Realtime, schedule of the transmitting times, frequencies, short path and long path beam headings for each beacon from your qth.
You are correct, the long path azimuth is simply 180 from the bearing listed in qrz. E3b05 20 meters is the amateur band that most frequently provides long path propagation. The only mf amateur band, 160m, will not be discussed, nor. Beaming long path means pointing your antenna 180 degrees different from the short path, or great circle heading, for a particular station. Mar 08, 2016 long path propagation is the type of propagation that occurs when the longer of the two direct paths between stations is better for communications than the shorter path. This includes the 80, 40, 30, 20, 17, 15, 12, and 10 meter bands. I have been listening to many stations and always hear them comment about using the short path in the mornings and long path at other times of day or vice versa. Understanding hf propagation conditions and predictions are important for your contest strategy to maximize the points. Particularly when using hf there may be more than one propagation path that the signal can take to get from the distant station to your receiver. All observations and recordings of echoes from long path show very low attenuation. On line propagation tools radio society of great britain main.
Hf propagation prediction is a statistical science. Review of propagation prediction programs voacapbased. Aug 14, 2015 hf radio propagation tools you can use hf radio propagation is the science and art of understanding how and when shortwave radio signals travel from a transmitter to a receiver. Ace hf professional propagation software for hf radio operators. The suns activity creates the hf propagation conditions and also. Ace hf pro hf propagation simulation and visualisation software. The application is an implanted sensor and i am asked to characterize the transmission channel. The main category is radiowave propagation resources that is about radio wave propagation links for amateur radio. Beaconsee analyses the audio signals from your radio, which is tuned to the ncdxf iaru hf beacon network and shows you the signal strength received from each of the 18 beacon transmitters as a plot of frequency spectrum against time. I have observed longpath openings to asia as far west as the sunset terminator. Hf propagation prediction the tools provided by this web application enable users to predict available frequencies, signal levels and corresponding reliabilities for high frequency hf circuits. Institute for telecommunication sciences resources radio propagation software radio propagation software. Propview propview uses the ioncap propagation prediction engine to forecast the minimum and maximum useable frequencies between two locations over a specified 24 hour period. I always seem to find the coolest stuff when im looking for something else.
About long path propagation the resource is currently listed in in a single category. All predictions are performed using the itus iturhfprop application. Jun 17, 2018 under the map, the distance calculations from tx to rx are being displayed in kilometers and miles, and the bearing in degrees from true north, via the greatcircle short path and long path. Ionospheric propagation is the main mode of radio propagation used in the mf and hf portions of the radio spectrum.
Hf radio dxing may often be leveraged by the use of hf long path lp from timetotime. Long path propagation can be confused with normal propagation when a beam has a significant lobe at 180 degrees to the main lobe. Propview propview uses the included ioncap propagation prediction engine to forecast the minimum and maximum useable frequencies between two locations over a specified 24 hour period. High frequency hf propagation models 230 mhz irregular terrain model itm longleyrice 20 mhz 20 ghz if77 wave propagation model gierhartjohnson airground the u. Radcom tools for pointtopoint monthly median hf propagation predictions to 28 different locations some including long path using userdefined mode.
This workinprogress guide should get you well started with the software. The earth is nearly a spherical object and the path taken by the radio signals to travel to the dx location is always. Realtime, schedule of the transmitting times, frequencies, shortpath and longpath beam headings for each beacon from your qth. Byandlarge, on a routine basis we all tend to explore hf radio propagation openings that prevail along the better known short path sp. Byandlarge, on a routine basis we all tend to explore hf radio propagation openings that prevail along the better known shortpath sp. It was the successor to my popular propagation program hfprop, which used a fast, but not very accurate propagation modelling algorithm. Short and long term prediction of ionospheric hf radio propagation. Excellent propagation info by geoffrey noles, ae4rv. According to the law of inverse square attenuation should be 10 log602 35 db.
The white ellipses are the calculated fresnel zones which help understand the effect of ground reflection on the path. Aug 05, 2012 long path propagation is the type of propagation that occurs when the longer of the two direct paths between stations is better for communications than the shorter path. It also features several propagation forecasting tools, allowing you to quickly and easily estimate current hf shortwave propagation conditions between any two locations in the world. The maximum usable frequency muf is the highest frequency that, with a probability of 50% of the time, can be used for radio communication between two points at a specified distance but not necessary in all directions via refraction by the ionosphere. Understanding radio wave propagation can mean the difference between making and missing a contact to a particular part of the world. Beaconclock freeware realtime, schedule of the transmitting times, frequencies, short path and long path. Dec 23, 2019 hf radio dxing may often be leveraged by the use of hf long path lp from timetotime. High frequency radio propagation current optimal frequency. A free online vhfuhf propagation tool for technical and non. Monthly forecast maps kindly provided by steve nichols g0kya, to whom any queries should be addressed. It also features several propagation forecasting tools, allowing you to quickly and easily estimate current hf shortwave propagation conditions. Your receiver receives signals from both paths, thus causing the echo. Hf radio propagation tools you can use making it up. So for the complete path to australia, the signal makes about 5 to 6 hops.
Beyond a short distance, shortwave radio signals travel by bounding off layers in the ionosphere. How do they work and how can you, as a radioamateur, use it in. Dec 15, 2012 so for the complete path to australia, the signal makes about 5 to 6 hops. Voacap voice of america coverage analysis program is free professional high frequency hf propagation prediction software from ntiaits, originally developed for voice of america voa. Usable hf frequencies page refreshed every 20 minutes use the indicated color red, yellow, green, blue, white, etc. 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. Listed under the propagation resources category that is about radiowave propagation resources.