As I write this in May 2021 there is much excitement in the amateur radio community as Solar Cycle 25 has been confirmed to have finally begun.
Every 11 years or so, the Sun’s magnetic field completely flips. This means that the Sun’s north and south poles switch places. Then it takes about another 11 years for the Sun’s north and south poles to flip back again.
The solar cycle affects activity on the surface of the Sun, such as sunspots and solar flares which are caused by the Sun’s magnetic fields. As the magnetic fields change, so does the amount of solar activity on the Sun’s surface which produce large emissions of radiations from the surface of the sun into space.
For amateur radio operators high solar activity means more favorable conditions for operating DX, or making long distance contacts. Radio waves, which are electro-magnetic can be reflected off of highly ionized layers of the earth’s atmosphere. The more ionization in the atmosphere, the better the operating conditions. When solar flares release radiation into space, that radiation will increase the ionization of the atmospheric layers where radio waves are reflected.
Thus operation conditions and the opportunity for DX contacts on the HF bands is expected to continue to improve as we head towards the anticipated peak of Solar Cycle 25, which should occur in 2025. This is great news for holders of General and Amateur Extra Class licenses as they both have broad privileges to the HF bands that will benefit from the increased solar activity.
The majority of amateur radio operators holding the entry level Technician Class license typically enjoy their on air time, operating inexpensive handheld transceivers to make contacts via local FM and DMR repeaters. Many Techs may enjoy the thrill of making “DX” contacts working other hams around the world via VOIP platforms like IRLP and Echolink which are accessible with their VHF/UHF privileges, but few take advantage of the opportunity to work “real RF DX” on the 10 meter band where they have limited HF phone privileges from 28.3 – 28.5 Mhz.
This is understandable, assembling an HF amateur radio station can be a daunting undertaking, and expensive. A new entry level multi-band transceivers such as the Icom IC-718 costs $600, and you can spent thousands more for more feature packed rigs.
Then there is the matter of choosing and raising an antenna for HF. This can be daunting as there are many varieties of antenna designs and there are many variables to consider.
Assembling a full featured HF station can be costly, complicated, and given that Technicians can only operate on the 10 meter band, doing so is a bit of overkill, at least until they upgrade.
This article provides information for the Technician licensee who would like to get on board to work DX on the 10 meter band as solar conditions improve. I will provide a technical primer on the 10 meter band and then thoughts, ideas and instructions on how to assemble a 10 meter only station, which not only easy and fun, it can be done for a fraction of the cost of building a multi-band HF station.
About the 10 Meter Band
The 10 Meter band is a low noise daytime band ranging from 28.000 – 29.700 MHz is at the very top of the HF frequency range. Here is the band plan for 10 meters:
If you would like to learn more about the 10-meter amateur radio band, may I recommend this excellent video by the Official SWL Channel on YouTube.
10 Meter Propagation
At peak times of the solar cycle, 10 meters will be alive with DX, refracting from the F2 layer in the ionosphere. The best propagation of 10-meter radio waves occurs during local daylight hours, but it is not unusual for the band to be open before sunrise and continue into the night when there are high sunspot activity.
The F2 layer forms during daytime hours between 200 km and 400 km above the earth. It is usually around all year around, and is at a higher altitude during summer months than in the winter. At night, the F2 layer will merge with the F1 layer to form a single F layer, which will be a bit lower in altitude than the F2 layer was during the day. Although the F2 layer exists all year long, it may sometimes disappear completely for days during a deep solar cycle minimum
In times of solar minimum, long distance contacts are still possible on 10 meters as Sporadic E propagation can bring in signals from a hundred to many thousands of miles away. Sporadic E is primarily seasonal with late spring and early summer being prime time for the mode.
Sporadic E arises when very intense clouds of ionization build in the lower reaches of the E region of the ionosphere. Sometimes these dense ionized clouds form suddenly and disappear just as suddenly minutes later. Sporadic E occurs most often in the months of June & July and December in evening, but it can happen at anytime.
During a Sporadic E incident, ionization may be up to five times greater than those normally achieved at the peak of the sunspot cycle.
The 10 meter band is the only HF band that is affected by Sporadic E propagation, is typically benefits the VHF range including 6 and 2 meters, but typically won’t affect frequencies below 28 MHz.
Assembling your fixed 10-meter station – Choosing a transceiver
The most essential piece of an amateur radio station is of course, the transceiver. Even with the mythological perfect antenna, you need a receiver to hear other stations and a transmitter to put your signal out.
Most commercial amateur radio transceivers today are multi-band, that is, they can operate on most or all of the MF and HF ham bands, and several will also have functionality for all mode VHF and UHF operations. You can spend anywhere from about $500 to several thousands of dollars for a state of the art HF transceiver, and this may make the prospect of setting up a station to work 10 M phone only a non-starter for the Technician.
Fortunately, there are more reasonably priced alternatives available in terms of new and used 10 meter only radios. A careful shopper can expect to pay anywhere from under $150 to $500 for a used or new radio.
My recommendations – used 10 Meter Rigs from the 1990s
I recommend the Technician looking to get on 10 meters first consider purchasing a used 10-meter only radio that is in good operating condition. In the 1980s through the early 2000s, Radio Shack, President and Ranger marketed 10 meter radios that have SSB phone functionality. If not abused and relatively well cared for, these radios will be an excellent choice for the 10 meter Technician.
Among these radios, I recommend the Realistic HTX-100, also marketed as the President HR2510, from 1988 into the 90s. The radio was manufactured by Uniden and featured 25 watts PEP output on CW and SSB. This radio lacks FM functionality, so you could not use it for 10 meter repeater operations. Today they can be found in working condition in the $100 – $200 range at hamfests, on QRZ.com and on eBay.
When shopping for an HTX-100 or HR2510, do be careful. Carefully examine the radio or seller photos and inquire not only whether the radio is fully functional, but find out if the radio had been modified. These radios were popular for mods, particularly for out-of-band transmitting. Ideally you want to find one that hasn’t been modified.
Watch for obvious signs of modifications, damage or abuse/neglect. Several of these radios today suffer from black marks on the LCD screen. As long as the frequency and other information on the display aren’t obscured by the black marks, the problem is only cosmetic and won’t affect the radio’s useability. Do watch for units that have no display functionality at all.
Another problem with these used radios is sometimes the frequency can’t be changed via the rotary encoder tuning knob. Radios in this condition can usually still be tuned via the up-down frequency buttons. If you decide on a radio with this malfunction, make sure the price you pay reflects this.
The President HR2600 was a follow up more upscale revision of the HR2510, also made by Uniden, but this time not available from Radio Shack as a Realistic variant. In addition to SSB and CW, the HR2600 was capable of AM and FM operation, and even included a CTCSS tone board for repeater operations.
Like the HR2510, the HR2600 had a power output of 25 watts PEP for CW and SSB, and could put out 10 watts on AM or FM. The same caveats as listed above for the HR2510 apply for shoppers looking for the HR2600. This radio can also be found in the $100 – $200 price range used today.
In the late 90s and early 2000s, Radio Shack marketed another 10 meter only mobile rig, the HTX-10. The HTX-10 was manufactured by Maycom. The chassis of the HTX-10 was considerably smaller than the HTX-100, more in line with mobile 2 meter FM or CB transceivers of this era. The HTX-10 did not have CW functionality, but did have AM, FM and SSB phone modes. The transmitter put out 7 watts PEP on AM, and 25 watts on SSB.
The HTX10 can be found on eBay and QRZ to this day and you can expect to pay anywhere from $100 – $150 for a unit in good operating condition.
Modern Options, aka “Export Radios”
Today most of the new radios sold as “10 Meter” radios are in fact not so much as intended for amateur radio operators, but for people to modify and operate illegal power in the CB band, or 11 Meter Range.
By law, CB radio operators are limited to 4 watts PEP in AM mode and 7 watts PEP when operating SSB. In 1982, President Regan signed into law a bill that allowed the FCC to stop issuing individual CB licenses and to scale back enforcement of operating rules on the citizen’s band.
Although the law eliminated the need for individual licenses, the FCC never changed the rules or regulations for use of CB radio. To this day it remains illegal to operate a CB radio with more than 4 watts PEP on AM or 7 watts on SSB.
Despite this, many folks today run illegal power in the 11 meter band and do so outside the pre-defined channel frequencies. They do this by either adding an amplifier to an existing CB radio, modifying a pure CB radio to put out more power, or converting a 10 meter amateur radio transceiver for use on the 11 meter band.
Several manufacturers today sell what are known as “export radios” – these are CB radios that can not be legally sold in most countries. Either the power output is too high, the frequency range is too wide, or some modes aren’t allowed. Some manufacturers use is to initially limit the frequency range to 28.000 – 29.700 MHz and advertise these radios as ham radio transceivers making them legal to sell to the amateur community. The majority of customers who purchase these radios are not amateur operators but radio scofflaws who will modify them into an (illegal) CB radio.
The catch for you, however is that these are actually what they claim – 10 meter amateur transceivers and they can be used to operate on 10 meters. Several are inexpensive and some are lacking in quality. Here are a few worth considering.
Ranger Communications is a CB and amateur radio manufacturer based in Taiwan with a USA division. Their radios have been manufactured overseas in plants in Vietnam, Malacca, Malaysia, Shanghai and Taiwan.
For years Ranger has sold a series of 10 and 12 meter radios for several years all featuring a similar form factor. This line of radios includes the RCI-2950 and RCI-2970 radios and in addition to being available used, new radios are still being produced with various features and identified by the model number suffix.
The Ranger RCI- 2950CD is a 10/12 meter transceiver that puts out 25 watts PEP on SSB and 8 watts on FM/AM and CW. The radio has a current MSRP of $290 new.
The Ranger RCI-2970N2 DX is a 10/12 meter transceiver that is capable of putting out a whopping 200 watts PEP on SSB and 100 watts on FM/AM and CW. It has an MSRP of $450 new.
In Feburay 1992 QST published a side-by-side comparison of the Ranger vs. the HTX100. In conclusion, the HTX came out ahead overall, and the ARRL was “generally disappointed with the RCI-2950. If you have any doubt who the Ranger line are marketed for, consider the fact that these radios have CB features such as the “roger beep” and PA, and adding ‘talk-back’ is a very popular mod.
Anytone, known today primarily for their DMR handheld and mobile radios, also offers a pair of 10 meter mobile radios. The current iteration is the AT-6666 and can be had from Amazon.com for $266 at the time of this writing. It puts out a hefty 60 watts PEP on AM and SSB, and 50 watts on FM.
The previous version, still available new is the AT-5555N. It puts out 30 watts PEP on SSB and FM, 12 watts on AM. Currently it can be found on Amazon for $230. I have not read or seen any reviews of these radios, but if you have used either, please feel free to drop me an email at email@example.com.
Of course you will need a resonant antenna in order to put your signal out on 10 meters, and the easiest and most inexpensive way to do this is to construct a classic half wave wire dipole antenna. Building your own 10 meter dipole is simple, easy, affordable and fun.
The dipole is a straight electrical conductor consisting of two equal lengths of #12 or #14 stranded wire with a combined length measuring 1/2 wavelength from end to end. It is supported with rope or nylon cored from the center and each end and connected at the center to a radio-frequency (RF) feed line that is then connected to your transceiver.
A half wave dipole cut and tuned for the center frequency of 28.400mhz should cover all of the Technician 200khz spread with low SWR and will allow you to work the entire sub-band without the need of a tuner.
Here is a list of all materials you will need for your dipole:
- 20’ of 12- or 14-gauge copper stranded wire
- Coaxial feedline – RG8X is sufficient and light
- Connectors and insulators
- 1:1 Balun (RF Choke), optional
The insulators can be homebrewed from any non-conductive material (glass, plexiglass, PVC, wood, commercial made insulators, etc. The center insulator actually can be used both for support at the center and to prevent the two outer radiators from touching and needs to be able to handle the weight of the entire antenna, coax and support ropes. if you incorporate the RF choke, that will do double duty as your center insulator.
A brief aside… Balun or no Balun?
Many recommend incorporating an RF choke or a 1:1 current ‘balun’ at the point of where the feedline meets the antenna elements. The word balun is an amalgamation of the words balanced and unbalanced and it provides common-mode isolation between the antenna and feedline. In our model, we only need it as an RF choke and serves the purpose preventing stray RF from coming back down the shield of the coax and into the shack.
My recommendation is that you may wish to initially construct your antenna system without the choke, and later modify the antenna if you experience a problem with stray RF. You will know you have a problem with stray RF if you experience RF burns, or you note RF interference with other electronic devices such as PCs, televisions, digital clocks while transmitting.
There are many 1:1 baluns available commercially from reputable manufacturers and retailers such as DX Engineering, Jetstream, MFJ, Quicksilver Radio and Radiowavz. A good rule of thumb in buying a balun is you can expect to get what you pay for – expect to pay $30 – $100 for a good balun and maybe avoid AliExpress, BangGood, and eBay. Expect to pay $30-$100 for a quality commercial current balun
You may also wish to construct what is known as an ‘ugly balun’ – which is easily constructed with a 25 feet of spare coaxial cable and should be effective eliminating stray RF issues. There are numerous resources for this on the web if you’re interested. Start with this HamUniverse article and/or watch Jim Haslett’s “How To” video here.
Choosing your feedline
Just as you need to make compromises when choosing an antenna, design, you need to select the best balance of different factors for your installation when choosing a coaxial feedline. These include:
For the 10 meter dipole, weight is your primary concern, followed by line loss and cost. Heavier feedlines add more strain to the antenna connections and support rope so a lightweight feedline is preferred. Regarding line loss, while higher frequencies mean higher line loss, at 28.3 – 28.5 MHz, still in the HF range, loss won’t be as significant of a factor as when feeding a VHF, UHF or higher band antenna.
RG8X provides a nice compromise of weight, loss and is particularly inexpensive. Calculated loss for a 50′ run of RG8X at 28.4 MHz with a load SWR of 1.5, is 17.84%. If you’re putting in 25 watts PEP under these circumstances, calculated power out is 21.89 watts; not bad at all. At the time of this writing, a 50′ run with SO239 connectors retails for less than $40 at QuickSilver Radio.
The last thing you will need to do before going on the air is to tune your half wave dipole antenna. The process is simple and straight forward.
The dipole antenna is to be tuned for the lowest SWR across the portion of the band you will be using it for. For our purposes, we want the lowest SWR for the Technician phone portion of the 10 meter band, which is 28.300 – 28.500 MHz.
Tuning for lowest SWR at 28.400, the mid point of the Technician phone sub-band will allow the antenna to perform well across the entire Technician sub-band.
The tools needed to tune the dipole are a pair of wire snips, a ruler, and either an HF antenna analyzer, the SWR meter built into your transmitter, or a stand alone SWR meter.
An antenna analyzer such as those by RigExpert or MFJ Enterprises is a handy tool for the radio amateur. These devices transmit low power RF to the antenna and provide a reading of SWR across a selected range of frequencies. However, new these meters cost $300 and up. Your elmer or local club may be able to loan you an antenna analyzer and even help you use it.
If your transceiver has a built in SWR meter, that can be used to tune the antenna. Stand alone SWR meters are relatively inexpensive and may also be used and placed between the antenna out PL259 on the rig and the coax feedline. If you are using your rig and an SWR meter to tune, you will need to set the radio for CW or FM as you need to transmit a carrier wave to get an accurate SWR reading.
- Raise the antenna into the air from the center insulator or balun and each of the ends. You may configure the antenna in an “Inverted V” position where each of the elements slope down at an angle of 45 degrees from the center insulator.
- Take an SWR reading at 28.3 and 28.5 MHz.
- Average the two readings. Ideally you are looking for an average SWR of 1.0 to 1.5.
- As long as the reading at 28.3 MHz is less than the reading at 28.5 MHz, the antenna is too long. Lower the antenna and snip off 2 inches from each end of the antenna. Make sure that the two elements remain the same length.
- Raise the antenna again, return to step 2 and repeat the process. Continue until the SWR falls into the desired range.
Once your dipole is in tune, you won’t have to fuss with it nor will you need to worry about using an antenna tuner. A properly tuned 10 meter dipole will be sufficiently resonant across the 0.2 MHz width of the Technician sub-band.
You’re on the air – congrats! Now what?
Now that you’ve assembled your 10 Meter station, it’s time to get on the air! But what can you do?
To help determine whether the band is ‘open’ or not, you can listen for beacons. Becaons are weak signal stations (less than 20 W, more commonly 1-3 watts) transmitting from various locations around the world – if you can hear the beacon, the band is open between you and the QTH of the beacon station. You can find a list of 10 Meter beacons here. Check out the Official SWL Channel video “What are 10 meter beacons?” to learn more.
On the air, you will find much to do on 10 meters. Beyond the anticipated DX openings due to Sporadic E and the increased solar activity from Solar Cycle 25, you will find special event stations and contests on the 10 meter band. Many of these events are produced and promoted by Ten-Ten International, a global organization first founded in 1962 in California, that promotes 10 meter activity and good operating procedures.
Membership in 10-10 is easy to achieve – all it takes is working and collecting the 10-10 number of ten members, plus $15 annual dues. In addition to programming on air events, 10-10 also publishes a quality quarterly, 10-10 International News.
The MARC/Castle Craig 10-10 Chapter holds a weekly net every Tuesday night at 8:00 pm local Eastern time at 28.375 MHz. Everyone is welcome to check in! If you’re not in the New Haven locale, look for 10 meter nets in your area. There are many out there, you may be surprised to find an active group near you.
I hope you found this article informative and useful. I hope it may have inspired you, whether you are a Technician or hold a higher level license, to get on 10 meters and enjoy the anticipated DX in the next few years. Spread the word – 10 meters is coming back!
Feel free to drop me at firstname.lastname@example.org if you have questions or wish to provide feedback.
73 de AB1DQ/James