Propagation Summary :: 902 - 928 MHz (33cm)

Ionospheric modes of propagation are nearly unknown in the bands above 902 MHz.
Auroral scatter may be just within amateur capabilities at 902 MHz, but signal levels will be well below those at 432 MHz.
Doppler shift and distortion will be considerable, and the signal bandwidth may be quite wide. No other ionospheric propagation modes are likely, although highpowered research radars have received echoes from auroras and meteors as high as 3 GHz.
Almost all extended-distance work in the UHF and microwave bands is accomplished with the aid of tropospheric enhancement. The frequencies above 902 MHz are very sensitive to changes in the weather.
Tropospheric ducting occurs more frequently than in the VHF bands and the potential range is similar. At 1296 MHz, 2000-km (1200-mi) continental paths and 4000-km (2500-mi) paths between California and Hawaii have been spanned many times. Contacts of 1000 km (620 mi) have been made on all bands through 10 GHz in the US and over 1600 km (1000 mi) across the Mediterranean Sea.
Well-equipped 903- and 1296-MHz stations can work reliably up to 300 km (190 mi), but normal working ranges generally shorten with increasing frequency.
Other tropospheric effects become evident in the GHz bands. Evaporation inversions, which form over very warm bodies of water, are usable at 3.3 GHz and higher. It is also possible to complete paths by scattering from rain, snow and hail in the lower GHz bands.
Above 10 GHz, attenuation caused by atmospheric water vapor and oxygen become the most significant limiting factors in long-distance communication.

Propagation Summary :: 430 - 450 MHz (70cm)

The lowest amateur UHF band marks the highest frequency on which ionospheric propagation is commonly observed.
Auroral signals are weaker and more Doppler distorted; the range is usually less than at 144 or 222 MHz.
Meteor scatter is much more difficult than on the lower bands, because bursts are significantly weaker and of much shorter duration.
Although sporadic E and FAI are unknown as high as 432 MHz and probably impossible, TE may be possible.
Well-equipped 432-MHz stations can expect to work over a radius of at least 300 km (190 mi) in the absence of any propagation enhancement.
Tropospheric refraction is more pronounced at 432 MHz and provides the most frequent and useful means of extended-range contacts.
Tropospheric ducting supports contacts of 1500 km (930 mi) and farther over land. The current 432-MHz terrestrial DX record of more than 4000 km (2500 mi) was accomplished by ducting over water.

Propagation Summary :: 222 - 225 MHz (135cm)

The 135-cm band shares many characteristics with the 2 meter band.
The normal working range of 222-MHz stations is nearly as far as comparably equipped 144-MHz stations. The 135-cm band is slightly more sensitive to tropospheric effects, but ionospheric modes are more difficult to use.
Auroral and meteorscatter signals are somewhat weaker than at 144 MHz, and sporadic E contacts on 222 MHz are extremely rare.
FAI and TE may also be well within the possibilities of 222 MHz, but reports of these modes on the 135-cm band are uncommon.
Increased activity on 222 MHz will eventually reveal the extent of the propagation modes on the highest of the amateur VHF bands.

Propagation Summary :: 144 - 148 MHz (2m)

Ionospheric effects are significantly reduced at 144 MHz, but they are far from absent.
F layer propagation is unknown except for TE, which is responsible for the current 144-MHz terrestrial DX record of nearly 8000 km (5000 mi).
Sporadic E occurs as high as 144 MHz less than a tenth as often as at 50 MHz, but the usual maximum single-hop distance is the same, about 2300 km (1400 mi). Multiple-hop sporadic E contacts greater than 3000 km (1900 mi) have occurred from time to time across the continental US, as well as across Southern Europe.
Auroral propagation is quite similar to that found at 50 MHz, except that signals are weaker and more Doppler-distorted. Auroral E contacts are rare.
Meteor-scatter contacts are limited primarily to the periods of the great annual meteor showers and require much patience and operating skill. Contacts have been made via FAI on 144 MHz, but its potential has not been fully explored.
Tropospheric effects improve with increasing frequency, and 144 MHz is the lowest VHF band at which weather plays an important propagation role.
Weather-induced enhancements may extend the normal 300- to 600-km (190- to 370-mi) range of wellequipped stations to 800 km (500 mi) and more, especially during the summer and early fall. Tropospheric ducting extends this range to 2000 km (1200 mi) and farther over the continent and at least to 4000 km (2500 mi) over some well-known all-water paths, such as that between California and Hawaii.

Propagation Summary :: 50 - 54 MHz (6m)

The lowest amateur VHF band shares many of the characteristics of both lower and higher frequencies. In the absence of any favorable ionospheric propagation conditions, well-equipped 50-MHz stations work regularly over a radius of 300 km (190 mi) via tropospheric scatter, depending on terrain, power, receiver capabilities and antenna.
Weak-signal troposcatter allows the best stations to make 500-km (310-mi) contacts nearly any time. Weather effects may extend the normal range by a few hundred km, especially during the summer months, but true tropospheric ducting is rare.
During the peak of the 11-year sunspot cycle (especially during the winter months), worldwide 50-MHz DX is possible via the F2 layer during daylight hours. F2 backscatter provides an additional propagation mode for contacts as far as 4000 km (2500 mi) when the MUF is just below 50 MHz. TE paths as long as 8000 km (5000 mi) across the magnetic equator are common around the spring and fall equinoxes of peak solar cycle years.
Sporadic E is probably the most common and certainly the most popular form of propagation on the 6 meter band. Single hop E-skip openings may last many hours for contacts from 600 to 2300 km (370 to 1400 mi), primarily during the spring and early summer. Multiple-hop Es provides transcontinental contacts several times a year, and contacts between the US and South America, Europe and Japan via multiple-hop E-skip occur nearly every summer.
Other types of E layer ionospheric propagation make 6 meters an exciting band. Maximum distances of about 2300 km (1400 mi) are typical for all types of E layer modes.
Propagation via FAI often provides additional hours of contacts immediately following sporadic E events.
Auroral propagation often makes its appearance in late afternoon when the geomagnetic field is disturbed. Closely related auroral E propagation may extend the 6 meter range to 4000 km (2500 mi) and sometimes farther across the northern states and Canada, usually after midnight.
Meteor scatter provides brief contacts during the early morning hours, especially during one of the dozen or so prominent annual meteor showers.

Propagation Summary :: 28.0 - 29.7 MHz (10m)

The 10 meter band is well known for extreme variations in characteristics and a variety of propagation modes. During solar maxima, long-distance F2 propagation is so efficient that very low power can produce strong signals halfway around the globe. DX is abundant with modest equipment. Under these conditions, the band is usually open from sunrise to a few hours past sunset.
During periods of moderate solar activity, 10 meters usually opens only to low and trans-equatorial latitudes around noon. During the solar minimum, there may be no F2 propagation at any time during the day or night.
Sporadic E is fairly common on 10 m, especially May through August, although it may appear at any time. Short skip, as sporadic E is sometimes called on the HF bands, has little relation to the solar cycle and occurs regardless of F layer conditions. It provides single-hop communication from 300 to 2300 km (190 to 1400 mi) and multiple-hop opportunities of 4500 km (2800 mi) and farther.
Ten meters is a transitional band in that it also shares some of the propagation modes more characteristic of VHF. Meteor scatter, aurora, auroral E and trans-equatorial propagation provide the means of making contacts out to 2300 km (1400 mi) and farther, but these modes often go unnoticed at 28 MHz.
Techniques similar to those used at VHF can be very effective on 10 meters, as signals are usually stronger and more persistent.

Amateur Radio Designs for Older Operators, by Alexander R. Vegh

Following several weeks of research and gathering Human Factors methodology design principals from various sources, I am pleased to present  a paper entitled "Wide-Ranging design goals and human factors methodologies applied to future Amateur Radio designs for Older Operators" Possible solutions for manufacturers for correcting some of the Human Factors related design shortcomings in future Amateur Radio Designs as it effects Older Operators are identified.

Currently several government, military, aerospace and commercial industries require Human Factors to be incorporated early in the new equipment design phase. I decided to analyze the apparent effects of a general lack of Human Factors design principals when applied to the Amateur Radio industry with special emphasis on how Older Operators are effected.

Why the focus on Older Amateur Radio Operators?

My research revealed some interesting statistics mainly that there presently ~ 3.6 million government licensed Amateur Radio Operators worldwide with the majority of countries reporting the average age of their Amateur Radio Operators being 60+.

Also worth noting, most new Operators wait until they are between 40 and 50 years of age before acquiring their Amateur Radio License.

With Older Amateur Radio Operators now demographically in the majority, Amateur Radio manufacturers must start adopting a New Wide-Ranging Design Philosophy which includes Human Factors Methodologies as applied to the special needs of an Aging Worldwide Amateur Radio Population.

With this goal in mind and offering some solutions for manufacturers to help with implementing this New Wide-Ranging Design Philosophy,  here then is my paper.

Alexander R. Vegh
Industry Canada Licensed Amateur Radio Operator
IC Authorized Call VE2VEH

Click here to download the complete article in MS Word format

Propagation Summary :: 24.89 - 24.99 MHz (12m)

This band offers propagation that combines the best of the 10 and 15 meter bands.
Although 12 meters is primarily a daytime band during low and moderate sunspot years, it may stay open well after sunset during the solar maximum.
During years of moderate solar activity, 12 meters opens to the low and middle latitudes during the daytime hours, but it seldom remains open after sunset.
Periods of low solar activity seldom cause this band to go completely dead, except at higher latitudes.
Occasional daytime openings, especially in the lower latitudes, are likely over north-south paths.
The main sporadic E season on 24 MHz lasts from late spring through summer and short openings may be observed in mid-winter.

Propagation Summary :: 21.0 - 21.45 MHz (15m)

The 15 meter band has long been considered a prime DX band during solar cycle maxima, but it is sensitive to changing solar activity.
During peak years, 15 meters is reliable for daytime F2 layer DXing and will often stay open well into the night.
During periods of moderate solar activity, 15 meters is basically a daytime-only band, closing shortly after sunset.
During solar minimum periods, 15 meters may not open at all except for infrequent north-south trans-equatorial circuits.
Sporadic E is observed occasionally in early summer and midwinter, although this is not common and the effects are not as pronounced as on the higher frequencies.

Propagation Summary :: 18.068 - 18.168 MHz (17m)

The 17 meter band is similar to the 20 meter band in many respects, but the effects of fluctuating solar activity on F2 propagation are more pronounced.
During the years of high solar activity, 17 meters is reliable for daytime and early-evening long-range communication, often lasting well after sunset.
During moderate years, the band may open only during sunlight hours and close shortly after sunset.
At solar minimum, 17 meters will open to middle and equatorial latitudes, but only for short periods during midday on north-south paths.

Propagation Summary :: 14.0 - 14.35 MHz (20m)

The 20 meter band is traditionally regarded as the amateurs’ primary long-haul DX favorite.
Regardless of the 11-year solar cycle, 20 meters can be depended on for at least a few hours of worldwide F2 propagation during the day.
During  solar maximum periods, 20 meters will often stay open to distant locations throughout the night. Skip distance is usually appreciable and is always present to some degree.
Daytime E layer propagation may be detected along very short paths.
Atmospheric noise is not a serious consideration, even in the summer. Because of its popularity, 20 meters tends to be very congested during the daylight hours.

Propagation Summary :: 10.1 - 10.15 MHz (30m)

The 30 meter band is unique because it shares characteristics of both daytime and nighttime bands.
D layer absorption is not a significant factor. Communication up to 3000 km (1900 mi) is typical during the daytime, and this extends halfway around the world via all-darkness paths.
The band is generally open via F2 on a 24-hour basis, but during a solar minimum, the MUF on some DX paths may drop below 10 MHz at night.
Under these conditions, 30 meters adopts the characteristics of the daytime bands at 14 MHz and higher.
The 30 meter band shows the least variation in conditions over the 11-year solar cycle, thus making it generally useful for long-distance communication anytime.

Propagation Summary :: 7.0 - 7.3 MHz (40m)

The popular 40 meter band has a clearly defined skip zone during the day due to insufficient ionization to refract high angles.
D layer absorption is not as severe as on the lower bands, so short-distance skip via the E and F layers is possible.
During the day, a typical station can cover a radius of approximately 800 km (500 mi). At night, reliable worldwide communication via F2 is common on the 40 meter band.
Atmospheric noise is much less troublesome than on 160 and 80 meters, and 40 meter DX signals are often of sufficient strength to override even high-level summer static. For these reasons, 40 meters is the lowest-frequency amateur band considered reliable for DX communication in all seasons.
Even during the lowest point in the solar cycle, 40 meters may be open for worldwide DX throughout the night.

Propagation Summary :: 3.5 - 4.0 MHz (80m, 75m)

The lowest HF band is similar to 160 meters in many respects.
Daytime absorption is significant, but not quite as extreme as at 1.8 MHz.
At night, signals are often propagated halfway around the world.
As at 1.8 MHz, atmospheric noise is a nuisance, making winter the most attractive season for the 80/75 meter DXer.

Propagation Summary :: 1.8 - 2.0 MHz (160m)

The 160m band suffers from daytime D layer absorption.
Daytime communication is limited to ground-wave coverage and a single E hop out to about 1500 km for well equipped stations (running the full legal limit, a quarter-wave vertical with a good ground system, and a low noise receiving environment).
At night, the D layer quickly disappears and worldwide 160 meter communication becomes possible via F2 layer skip and ducting.
Atmospheric and man-made noise limits propagation.
Tropical and mid latitude thunderstorms cause high levels of static in summer, making winter evenings the best time to work DX at 1.8 MHz.
A proper choice of receiving antenna (Beverage, 4-square, small loop) can often significantly reduce the amount of received noise to improve the signal-to-noise ratio.