The Myths of Low Band DXing by Gerry, VE6LB
"VE6LB, you're 58 on Norfolk Island, over" "VK9NS, thanks Jim you're 59 here in Calgary, 73s". Sounds like a typical 20 meter exchange doesn't it? The exchange is typical, the DX is semi-rare, but the band is 80 meters.
I was surprised at the number of amateurs who have comment that they have never heard DX on 80 meters much less work any. The purpose of this article is to dispel some of the myths of working DX on the low bands.
As the sunspot cycle declines and propagation on the higher frequencies diminish, there will be more of an operating focus on the less solar effected low bands (40, 80 and 160 meters). The prospects for working DX on these bands will increase due to the increased activity, as the higher bands will be closed more often, and the lower atmospheric noise because of lower levels of solar activity. My examples will refer to 80 meters although the same basic apply to the other low bands.
There are a number of common myths about low band DXing that I hope to dispel. These are:
1. There is no (or little) DX on the low bands!
2. You need a big antenna and high power (it's only for the big guns) to work DX on the low bands!
3. DX is so scares that you need to spend many hour (mostly late at night) to find DX on the low bands!
4. Any DX to be found on the low bands is on CW!
5. There is no low band DX during the summer!
6. The low bands are too noisy to work DX!
Before attacking these myths, I'd like to relate my success in working DX on 80 meters with modest means.
Over the last three years, I've worked over 100 80 meter countries over all continents split about 40% SSB and 60% CW. The first 50 counties where worked with a garage roof mounted GAP DX VI and 100 watts. The balance where worked using and inverted "L" wire antenna stapled to our two story wood frame house with a wooden pole twelve feet long above the roof to get the antenna apex up to 35 feet. The balance of the antenna length, 30 feet, was tied back to the far end of the house at a slight downward angle. The power was also increased to 500 watts for the second (and tougher) 50 countries.
Now, to dispel the myths, point by point, and then provide some tips on low band DXing, then to get on with successful low band DXing.
1. There is a surprising amount of DX on the low bands, the secret is to know when and where to listen for it (this also applies to the high band). During the hour of darkness the low band are often open to various parts of the world depending on the time and season. More on this in the following tips.
2. Simple vertically polarized wire or tubing antenna, with a good ground, will do a surprisingly good job. The vertical polarization will provide a low angle of radiation and minimize the path losses to the DX station. These types of antennas will not be a star performers for short hop work.
3. You don't have spend your life in front of the rig to work low band DX (this applies equally to high band DXing). The secret is to make effective use of your time by being in front of your rig when there is a high probability of the DX also being there. By understanding propagation characteristics and the operating habits of your target DX you can be in the shack at the time when you have the best chance to work DX. It is true that to be wildly successful at low band DXing you will have to give up some sleep late at night and early in the morning to be at the rig. I had the good fortune to have a dog who understood my need to catch a few new ones and scratched at the door to go out in the wee hour. She became known locally as "the DX dog" as more often than not there was a new one on the air during her nocturnal trips.
4. There is lots of DX on both SSB and CW but you have to know where on the band to find them. On the low bands the DX frequents specific areas of the bands, sometimes by convention and in some countries, by regulation. More on this in the following tips.
5. There is considerable and unique DX on the low bands during the summer. Although the low bands are noisier due to summer static and electrical storms, there are still excellent openings especially in the morning hours when the bands quite down. Also, there is a different selection of DX opportunities in the summer due to the unique alignment of the Gray Line, and therefore the Global darkness pattern, compared to winter propagation patterns. Don't forget, Summer in North America is Winter in Australia.
6. Yes, the low bands are generally noisier than the higher bands but that noise comes from two sources. One being atmospheric noise, storms, static, etc. and the other being local man made noise. The good news is you can often reduce the man made noise with a bit of detective and corrective work. Much of the "noise" is man made and is likely within or near your home. In my case the major source of "noise" was a couple of older light dimmers that put out significant (S9 on 80) interference.
Tips to Successful Low Band DXing.
1. When to Listen:
Openings to South America and the Caribbean start at our sunset and continue until our or DX local sunrise. Openings to the Pacific start after our sunset and after sunset at the DX's location. The most valuable tool to predict when the band may be open in a computerized (DX Edge, Geoclock, Miniprop Plus, etc.) or paper (DX Edge) tools that shows the Gray Line. The Gray Line is the period of semi-darkness that is created as the Earth rotated from night to day and day to night. This Gray Line or "Terminator" changes with the seasons as the tilted axis Earth rotates around the Sun. This change in Gray Line patterns with the seasons has a major effect on what DX can be worked when.
2. Coincident Gray Line openings.
The optimum time to work East/West (including N/E, S/E, N/W and S/W) DX is when both ends of the path are in near darkness which is when they are both in their respective Gray Lines. This is due to a refraction effect in the Ionosphere that "ducts" the signals between the coincident Gray Lines. This includes the long path when, as an example, fall and early winter offers some great long path openings to Europe around our sunrise (their sunset).
3. Contests and DXpeditions:
Many times the low bands are open to some exotic location but due to their time of day, nobody is on the air. During contest and DXpeditions there are good opportunities to increase your low band country count as these operations are on the air at all hour and on all bands that are open. I've worked at least 50% of my low band DX during contests. These operators know when it is sunset/sunrise in North America and specifically look for us. "QRZ North America only" can be often heard from the DXpedition.
4. Low Band Openings:
The opening on the low band can be very localized. I have experienced many occasions when rare DX (eg. 6W6 or AH5) will be calling CQ and few or no stations coming back to them. In these cases, working them was quite easy.
5. Information Sources:
There are many good sources of information on DX. DX Packet Clusters, packet DX bulletins (LS DX), various general amateur publications (QST, CQ, etc.), DX bulletins and magazines (QRZ DX, DX Bulletin, DX Magazine, Canadx, etc.), DX Nets (INDEXA 14.236 @23:30Z daily) and on air discussions with other low banders.
One sure way to improve your success in low band DXing is to gather as much intelligence about DX stations operating the low bands as possible. From various sources of information as discussed previously, determine the operating habits of the target DX, when and where they have been heard in your area, and plan your operating plan accordingly.
Understand how the propagation information broadcast on WWV, at 18 minutes after the hour, effects the low bands. Basically a low K index (0-2) and quite or better solar forecast improves your chances of hearing low band DX.
8. Where to Find DX:
Low band DX can be found in very specific places on the band, more specifically than the higher bands.
On CW: Most DX frequent the every low end of the bands, usually the bottom 10 KHz. The exception to this is contests, where up to 30 KHz may be occupied and DXpeditions, which will specify specific frequencies.
On SSB: Most of the SSB DX operates in specific "window" in the low bands.
40: 7050 to 7100 but mostly nearer 7050 with the DX listening on their frequency and/or a declared split in the US phone band.
80: The DX window is 3790 to 3800 and this is where most of the activity happens. Many countries do not allow Amateur operation above 3800 KHz although some DX such as South America and some Pacific can be found above 3800 and down as low as 3775. The area of activity expands during contests.
160: 1800 to 1850 for both CW and SSB as many countries only allow amateur operation in this narrow window.
9. Noise: As mentioned earlier, noise can be a problem on the low bands. There are several ways to reduce the noise component of the wanted signal such as noise blankers, external (audio) bandbass/noise filters, adjustment of tone and IF shift controls. One trick is to run your AGC off or fast and turn back your RF gain. Also, the use of your highband antenna for receive can often improve the signal to noise ratio.
There is not a lot of information published about subjects related to low band DXing. The following is few publications that I have found useful, all of which are available from RAC:
- Low Band DXing by ON4UN
- All About Vertical Antenna Handbook by W6SAI/W2LX
- The Compete DXer by W9KNI
- Radio Frequency Interference: how to find it and fit it by ARRL
Similar operating strategies apply to the high band. In the last 3 years, I have been successful in working over 300 countries and 5BDXCC using simple wire and vertical antennas such as the R5/GAP and conservative power of 100 and 500 watts.
One of the greatest feeling, even for an old high band DX hound, is to work even a semi-rare one on 80 meters. It can be done and it doesn't take big antenna, high power or living in your shack. It does take working smart.
Happy and effective low band DXing.
Originally published in CQ, TCA and Key Klix in 1993/1994
Update: November 1997
Since this article was written in 1993 I have been focusing on 160 DXCC using for the last 2 Winters using an unmodified Cushcraft HF-2V with their 160 meter base load kit plus an AL80A linear. This antenna is commonly referred to by the Top Band community as a inefficient dummy load. To date I've managed 65 countries with the HF-2V plus 7 more since I've modified this antenna by adding a small "top hat" and an 8 foot section with a large loading coil near the top. The improvement has been dramatic in that I went from waiting in a pile-up until I was amongst the last to call and thereby had a clear frequency to being able to break European pie-ups in the first few calls. The good news is that this modest 160 antenna work much better than expected, I suspect largely due to the 20 32 foot radial around it's base. The bad news is that "DX Dog" doesn't have a clue about 160 propagation. On the odd occasion she does get me up in the middle of the night, 160 is barren. Must have been a single band dog.
The methods used on 160 are certainly the ones outlined above plus a few new ones learned such as timing your call to help the DX hear at least part of your call with a minimum of competition and calling a couple of hundred cycles high or low from the DX's frequency.
Update: October 1999
In June, 1999, VE6LB was awarded 160 DXCC #800, the 1st. VE6 to achieve 160 DXCC.
(published first by Gerry, VE6LB in CQ TCA and Key Klix 1993/1994)