The 2 Meter Band: Much More Than FM
Way back in the Wayback machine, when I was working on getting my Technician license (in the 20th century), I recall looking at the frequency bands available to Techs. Technicians had operating privileges for everything above 50 MHz, which looked like a lot of useful spectrum to me. The idea at the time was that Technicians were exploring the new frontier of amazingly high frequencies. Since then, the Technician license has morphed to be the entry level license.
ICOM has a good graphic that shows all of the ham bands and shows the common subbands for various modes. I snipped out the portion that covers the most popular VHF/UHF bands (below). Wow, look at all the stuff you can do! Also, it is 4 MHz of spectrum, big enough to fit eleven 20 meter bands inside it. (Yeah, yeah, the propagation is a lot different.)Speaking of bandwidth, take a look at the 70 cm band, with 30 MHz of spectrum. (Not shown is the 23 cm band, which spans 60 MHz.) The higher you go in frequency, the more spectrum there is.
Most people think of the 2-meter band as just FM and repeaters, but it is much more than that. I copied the 2-meter band graphic and added my own notatation on the various uses of the band.
Much of the band is allocated to FM, which is consistent with the popularity of the mode. I didn’t mark all of the FM segments, so refer to the color coding to see them. But there is much more than FM simplex and repeaters. Down on the low end is the CW-only segment and EME activity (Earth-Moon-Earth or moonbounce). The “weak-signal” enthusiasts tend to use the SSB portion, with the SSB calling frequency of 144.200 MHz. You may often hear CW in the SSB subband and radio hams flip back and forth between the modes depending on propagation. Meteor scatter is mostly done via the WSJT-X mode of MSK144 around 144.140 MHz.
Automatic Packet Reported System (APRS) activity is mostly on 144.390 MHz, using FM-based 1200-baud packet radios. Other packet radio usage is not shown but is usually around 145.01 MHz. The 2m band is very attractive for satellite use, with VHF propagation properties and manageable doppler shift for Low Earth Orbit (LEO) satellites. The downlink from the International Space Station (ISS) is usually 145.80 MHz.
Over time, I’ve used all of these 2m modes mentioned above, with the exception of EME. I am still working on that one and I hope to have a new 2m Yagi installed sometime this year that will enable it.
73 Bob K0NR
The post The 2 Meter Band: Much More Than FM appeared first on The KØNR Radio Site.
I have had many tropo ducting qso’s on 2 meters with stations 150 miles or more up the eastern coast of Florida using 10 watts and a 2 meter quad. These were early morning contacts during the sunrise. Tons of fun!
I’m doing MSK144 every morning until before 1500 UTC at 144.150 Mhz, I have the antenna oriented at 23º, my location is Tegucigalpa, Honduras EK64jc