About the 144 MHz Band ….
For many this band is their first introduction to VHF and for some their only VHF band. That’s not to say that the 2M band holds nothing of interest. Actually 2M is an extremely fun band and a mainstay for many transmission modes and has a great variety of propagation to hold the interest. It is also a main band globally and most countries have a 144 MHz allocation that allows inter-continental DX via satellite and modes like Moonbounce.
Apart from the weak signal sections the band also offers local communications using FM by direct simplex contacts, but also via a huge array of repeaters and Internet Relay Linking and Echolink nodes. Packet radio also used to be a very popular mode on this band but since the growth of the Internet over the past 15 years this mode has been largely dropped and replaced by modes such as APRS and DSTAR. Amateur Satellites and manned space vehicles such as ISS also have uplinks and downlinks in this band.
For the weak signal operator the band offers the first real chance of long distance contacts using Tropospheric ducting, sometimes over many 1000’s of Kms. Again all the regular long distance propagation modes such as Sporadic E, Aurora, Meteor scatter etc are present.
Moonbounce (EME) is also another growth mode on 144 MHz. Using new designs for optimized yagis and the introduction of new digital modulation techniques such as JT65, and the use of a home PC in DSP recovery of signals, EME has now become possible for a whole new generation of operators who would have never attempted this mode. Similarly, the use of digital modulation and DSP recovery has revolutionized Meteor Scatter, and has mostly replaced the old high speed CW methods of Meteor Scatter operating. The use of JT65 has also led to a vast reduction in station requirements and even single Yagi low power stations can made 100’s of contacts across the globe.
More unusual propagation modes have also been discovered on the 144 MHz over the past 10 years or so. Now long distance contacts are also made using unusual modes like Ionoscatter and a mode known as Field Aligned Irregularity, or FAI for short. Reflections from Aircraft is also a popular mode on this band. Signals have also been bounced off the International Space Station using passive satellite scatter. These were received across the Atlantic between the USA and UK.
All up the 144 MHz band is still as popular as ever, with all of the top manufacturers offering a wide range of handheld, mobiles and fixed station equipment either in single or dual / multiband versions. 2M is also a band where the transverter remains popular for high performance weak signal work and a number of suppliers offer built and kit transverters.
The 144 MHz band has also been a beneficiary of the mobile phone with new high power LDMOS devices s available at relatively good amateur prices, which has allowed the development of new solid state power amplifiers well into the Kilowatt range.
Modern personal computer processing power has also allowed the development of new highly optimized long Yagis for this band which has extended the range of modern 144 MHz stations even further.
However not all changes have been good for the 144 MHz band.
Due to the introduction of modern PCs and networking, cable TV and Internet routers across power lines, this band has, in places, become extremely noisy and this can limit some operators. Despite this 144 MHz remains an extremely popular and well used band offering some exciting challenges especially in the area of EME.