25 Aug Amateur Microwave. It’s easier than you think!
Last Updated on August 25, 2021
Getting started with the Amateur Radio Microwave Bands
Microwaves are the highest frequency radio bands in Amature Radio. It’s the final frontier for many amateur radio operators offering unique challenges with big rewards.
Amateur Microwave offers access to relatively large segments of the radio spectrum. If you live in an elevated area with panoramic views, then you’re in a lucky minority who can work the microwave bands from home. If not, going portable is for you.
The amateur microwave bands are under pressure by the demands of commercial operators and the revenue this precious commodity can generate governments around the world.
Already there’s been far too much spectrum being eaten out of amateur allocations globally. The accompanying video on this blog will point you in the right direction for equipment and resources and hopefully spur you on to get active in microwave.
A great way and probably the best way of slowing the loss of amateur microwave bands is by using them.
In August 2020, US amateurs lost access to the 9cm band. In an online post the ARRL said, “Despite vigorous opposition from ARRL and others, the FCC has ordered the “sunsetting” of the 3.3 to 3.5-GHz allocation” “The FCC proposed two deadlines for amateur operation to cease. The first would apply to the 3.4 to 3.5 GHz segment, the second to 3.3 to 3.4 GHz.”
The good news – There has been a temporary FCC reprieve. The not so good news… in Australia, amateurs lost the 9cm band above 3.4 GHz some time ago.
Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays. The human eye can only detect only a small portion of this spectrum called visible light. A radio detects a different portion of the spectrum. The microwave spectrum is usually defined as a range of frequencies ranging from 1 GHz to over 100 GHz.
In Australia, the microwave bands are available to two of the three licence types.
The foundation licence doesn’t have access to the microwave bands, but that doesn’t mean those who hold this entry-level qulification can’t experience microwave communications.
By getting involved with radio clubs and field days – even reaching out to local operators who are active microwave users, foundation ops can give these bands a try. The experience will hopefully encourage a licence upgrade.
Microwave bands, as far as the amateur radio community go, start at 1.2 GHz or 23cm. Although technically speaking this isn’t really microwave, It’s the limit of the commercial ‘black box’ or radio you can buy from the toy shop. This is good as it allows instant and easy access to 1296 MHz. (23cm)
The now-ubiquitous Icom IC-9700 has been in circulation since early 2019. Ross from Strictly Ham, one of Australia’s largest suppliers of amateur radio equipment, estimates there’s over 500 IC-9700s in the Australian wild. If you can, why not get your station active on 1296.1 SSB or if your passion is FM move your local chat to 1294 MHz.
Microwave is usually defined as a range of frequencies ranging from 1 GHz to over 100 GHz. This range has been divided into a number of frequency bands, each represented by a letter.
The black rectangles in this graphic highlight the amateur bands, and as you can see there are allocations all over the microwave spectrum.
There are a number of organizations that assign letters to these bands. The most common being the IEEE Radar Bands, but in Amateur radio, we normally refer to them by their frequency.
The popular 4 bands are 13, 9, 6 and 3cm.
If you’re keen to dip your toe in this aspect of our hobby, there are some great resources at your disposal. On Facebook, the VHF UHF Microwave group for VK and ZL is a great place to see what others are doing and to ask questions. Also, have a look at the Brisbane VHF Group if you’re in that part of the world. Even if you’re not, there’s some great reading on their website.
DUBUS magazine is an international amateur radio magazine intended for the serious VHF and up operator. Published in Germany, it’s also in English. There are four issues a year, each of over 100 pages which are devoted to a mix of state-of-the-art technical articles and DX operating news.
If you’re in Australia or New Zealand, you can subscribe to Dubus by contacting Alan VK3XPD whose details are on the Dubus website. It’s an annual subscription around the $50 AUD mark.
Don’t underestimate Youtube. Many amateurs publish their microwave activity on this platform. The comments section is a great place to ask questions.
Microwave Activity Days known as MADs are ad-hoc events organised on a local area basis. The purpose of these days is to get out of the shack and go portable on mountain tops. In VK3 this can result in as many as a dozen or so stations statewide enjoying the great outdoors.
Let’s talk about the equipment you’ll need and where to get it in order to get on the air. You can certainly build everything yourself, or you can buy equipment to fit the bill.
There’s no turnkey solution at frequencies above 23cm. Yes it’s true you have to build things, and yes, it can be more plumbing than cabling, but the reality is, it’s a part of the spectrum that has its own unique rewards.
Generally speaking, there are three parts to a microwave station. An IF radio, a transverter, and an antenna. Sequencers such as the Minikits EME-166 kit can be used to control transverters with various components like antenna relays, power amplifiers, or receive pre-amplifiers. It is also suitable for sequencing the switching of high power RF amplifiers with a transceiver.
Hit up eBay and find a 2.4 gridpack for home or portable use. They’ll set you back about $100 or so. Always use good quality coax NOT RG-213 and be sure to keep your cable runs short.
A transverters is a device that consists of an upconverter and a downconverter in one unit. Two good reliable sources of quality transverters are Kuhne, a German-based company and SG Laboratory, which is based in the Bulgarian capital, Sofia. There are others such as Down East Microwave based in the US.
Kuhne transverters are works of art. Exceptionally well built and designed, they’re robust and easily configured but they come at a price.
You can’t go past the SG Lab transverters. They’re everywhere here in VK3. They also come with a PCB antenna which performs pretty well considering.
The main types of antennas used for microwaves are parabolic dish antennas, grid packs, panels, and PCB antennas.
Hit up eBay and find a 2.4 gridpack for home or portable use. They’ll set you back about $100 or so. Also, there will be a good selection of 5.7GHz antennas. Use good quality coax and NOT RG-213. Be sure to keep your cable runs short.