ARRL 10 GHz and Up Contest: Microwave Rovers and Hilltops
At 10 GHz the wavelength is only three centimeters, antennas are small dishes, and a signal usually needs a line of sight between hilltops to reach its destination. That makes it a very different sport from HF contesting, and one weekend pair each year is devoted to it. The 10 GHz and Up contest, run by the ARRL, invites North American amateurs to work on the microwave bands from 10 GHz all the way up to light. This guide explains what the official page says about the dates, the operating limit, the objective of working many different locations, how logs are submitted, and what a beginner needs to know about equipment and operating practice before trying the microwave bands for the first time.
What the Contest Is
According to the ARRL contest page, the objective is for North American amateurs to contact as many amateur stations as possible, in as many different locations as possible in North America, on bands from 10 GHz through light. Amateurs are encouraged to operate from more than one location during the event. That is unusual, because most contests reward staying at one fixed station. Here the scoring philosophy rewards moving: a rover who drives to several hilltops gets more distinct locations to work and more distinct stations to contact, and a fixed station gains by working them.
The phrase “through light” refers to optical communication. Microwave enthusiasts experiment with modulated light beams, including lasers and high-power LEDs, for line-of-sight contacts over many kilometers. Few operators try this, but the contest recognizes it as part of the same family of experiments. Most activity is on 10 GHz, with fewer stations on the higher bands.
Dates and Operating Limits
The contest has two weekends. The page gives the dates as the third full weekend of August and September, and lists August 15-17, 2026 and September 19-21, 2026. Each weekend begins at 0900 UTC on Saturday and runs through 0759 UTC on Monday. Participation is limited to 42 hours of operating time in each of the two contest weekends, so you can pace yourself within the long window instead of staying up for the whole period. The page also notes that the start and end times changed from earlier years, when they were expressed in local time, and reminds participants to log all contacts in UTC.
The 42-hour limit is a good example of how a microwave contest differs from HF. Propagation on these bands changes slowly, equipment is carried to a hilltop and set up by hand, and the best conditions often occur at dawn and after sunset. You can plan to operate at the best times, and spend the other hours on travel, rest and moving between locations. If you plan to take part, check the hours in your own time zone, because 0900 UTC is early morning in North America and the Sunday-to-Monday transition falls in the night.
Why Locations Matter
The emphasis on different locations is not an accident. A contact is a path between two points, and on 10 GHz the path must usually be unobstructed. A station at a good hilltop can see far more of the horizon than a station in a valley. The same station operating from three different places can work three different groups of other stations. The contest page links to detailed rules on restrictions, so read them before you plan a multi-location route.
It helps to understand how far the signals can go. The geometric limit for line of sight depends on antenna height, a subject that we cover in our guide to the radio horizon. On microwave bands, the practical range is often a little more than line of sight because of atmospheric refraction, and longer distances are possible with tropospheric ducting, a mode we describe in our guide to tropospheric ducting. Rain scatter is another mode that microwave operators use: a heavy rain cell at the right distance scatters energy toward the other station, which opens contacts that are impossible by line of sight.
Narrowband and Wideband Operation
Microwave stations come in two broad types, and both take part in the contest.
| Type | Typical mode | Equipment | Strength |
|---|---|---|---|
| Wideband | FM, often with a simple transceiver module | Small dish, Gunn-type or modern synthesized module | Low cost and easy to build |
| Narrowband | SSB and CW | Transverter from a 144 or 432 MHz radio, dish, stable oscillator | Much better sensitivity and range |
| Digital weak signal | Modes such as those in WSJT-X | Narrowband station with a stable reference | Works at the edge of the noise |
| Optical | Modulated light | Lens, laser or LED, photodiode | Experimental, line of sight only |
The wideband stations are the easiest way to start; older designs were built around a Gunn diode oscillator, and newer modules use synthesized sources. They are easy to start with because a small kit can be built in a weekend and is cheap enough to use for experiments. The narrowband stations use a transverter, which converts the microwave frequency to an intermediate frequency such as 144 MHz or 432 MHz, so that an ordinary SSB and CW transceiver can be used. A narrowband station needs a stable oscillator and good frequency reference, because at 10 GHz even a small error is a large frequency offset. The narrowband calling frequency on 10 GHz is generally found near 10.368 GHz, but check the current convention in your region before you rely on it.
Equipment Basics
A basic 10 GHz station has four parts: a dish antenna, a feed, a transverter or transceiver module, and a way to point and power it. Dishes are small. Because the wavelength is only three centimeters, a dish of modest size gives high gain, and the beam is very narrow, so pointing accuracy matters. A small error in aiming can lose the signal completely. For that reason, operators carry a compass, a map or a smartphone, and often use a visible light source or a mirror to align dishes at long range.
Waveguide and coaxial connectors are another special feature of microwave work. Ordinary coax loses a large share of the power at 10 GHz, so builders keep the feedline very short and often mount the transverter directly at the feed. Connectors are typically SMA or N type, and waveguide flanges and adapters appear on the more serious stations. Weatherproofing is a concern, and cables and connectors should be sealed carefully; our guide to weatherproofing coax connectors explains the basic methods.
It is also useful to learn about the nearby bands. Many operators start on 1296 MHz and 2.3 GHz and move up, using the same techniques and the same transverter ideas at each step. Our 23 cm band guide is a good introduction to the first of those steps.
Safety, Weather and Practical Logistics
Microwave contesting means hiking or driving to exposed places, so plan for the conditions. Check the forecast before you leave, carry water and warm clothing, and tell someone where you are going. A dish is a sail, so secure it firmly against wind, and never set up near power lines. At the frequency of 10 GHz, the beam from a transmitting dish is narrow but can be strong in front of it, so keep people out of the beam and do not look into the feed while transmitting. Follow the RF exposure guidance that applies in your country, as you would for any amateur station.
Power is another practical matter. Portable stations need batteries that last for the whole session, and a transverter can draw a surprising amount of current compared with a simple FM module. Our guide to weatherproofing coax connectors helps with the outdoor side, but a checklist is also useful: batteries charged, compass, map, headlamp, logging device, spare cables and a notebook for paper backup. Write down your grid square at each location before you transmit, because a wrong grid in the log can cost you contacts at the checking stage.
Why the Microwave Bands Matter
The microwave bands give amateur radio a place for experimentation that is not available at lower frequencies. The antennas are small enough for one person to carry, the bandwidth available is large, and the techniques learned here are the same ones used in commercial links and satellite communications. The contest also keeps these allocations active, which matters because spectrum that is not used is spectrum that can be questioned. Taking part, even with a basic station and a few contacts, is a contribution to that activity and a good way to learn a branch of radio that most hams never see.
How Operating Works
Contacts are made by arrangement far more often than by calling CQ. A typical sequence is for stations to announce their location and times on a local chat group or on a calling frequency, then to set up a schedule, point their dishes at each other and exchange callsigns, grids and reports. Grid squares are the standard way to describe location in this activity. If you are not sure how they work, our guide to grid squares and the Maidenhead locator system explains the notation.
Because the beams are so narrow, the usual practice is to find the other station using a more tolerant band first, usually 144 or 432 MHz, and to use that contact to give directions: “I am at the northwest corner of the parking area, please point at azimuth 135”. Then both stations swing to the microwave band and make the contact. This technique saves a great deal of time and is a good reason for a microwave operator to keep a VHF radio next to the transverter.
Logging and Submitting Your Entry
Logs are due no later than 30 days after the second weekend ends. Logs may be submitted online or by mail, but electronic Cabrillo logs are the preferred method; the ARRL web app for 10 GHz and Up submissions is described on the contest page. If you submit on paper, you mail a completed summary sheet and log sheets, postmarked before the deadline, and the ARRL recommends a delivery method with a tracking number. A conversion tool for Cabrillo files is available through a link on the page. The ARRL also states that suitable certificates will be awarded online for exceptional operating efforts.
For the full rules, including how scoring works and which restrictions apply, download the PDF linked from the page. This article does not reproduce the scoring formula, because the details can change between years and the PDF is the definitive source. If you plan to take part more broadly in ARRL VHF-and-up events, our guide to the ARRL VHF contests gives the schedule and grid-based scoring.
A Beginner’s Plan for the Next Event
- Start with one band. Build or buy a 10 GHz setup and test it at short range with a friend.
- Find local activity. Ask local clubs or VHF groups who is active on microwaves, and ask to join a field session.
- Choose a good hilltop. Use a map and the radio horizon calculation to pick a location with a clear view in several directions.
- Prepare a log. Record the UTC time, band, callsign and grid for each contact.
- Keep the 42-hour limit in mind. Plan your operating time around the best hours for the path and keep a record of the hours you use.
- Take care with safety. Microwave transmitters can be hazardous at close range, so never stand in front of a dish that is transmitting, and observe the RF exposure rules for your country.
The Bottom Line
The ARRL 10 GHz and Up contest is two long weekends, each starting at 0900 UTC on Saturday and ending at 0759 UTC on Monday, with a limit of 42 operating hours per weekend, and it rewards working many different locations on the microwave bands from 10 GHz to light. A small wideband station is a cheap way in, a narrowband transverter station is a better long-term goal, and success depends mostly on a good hilltop and careful dish pointing. Read the rules PDF, plan your locations, log in UTC and submit a Cabrillo file within 30 days after the second weekend.
Frequently Asked Questions
When is the 10 GHz and Up contest?
On the third full weekend of August and the third full weekend of September. The page lists August 15-17 and September 19-21 for 2026.
How long is each weekend?
Each weekend begins at 0900 UTC Saturday and runs through 0759 UTC Monday, with a limit of 42 hours of operating time per weekend.
Which bands are included?
Bands from 10 GHz through light, for contacts in North America.
Why operate from several locations?
The objective is to contact as many stations in as many different locations as possible, and amateurs are encouraged to operate from more than one location.
How do I submit my log?
Electronically in Cabrillo format through the ARRL web app, which is preferred, or by mail on paper. Logs are due 30 days after the second weekend.
Do I need narrowband equipment?
No. The contest accepts any equipment, but narrowband SSB and CW stations with transverters generally reach farther than simple wideband FM modules.