Saturday, July 23, 2016

QRP Contesting Tips

I have written several articles in this blog about the challenges and techniques to be successful running QRP power (5 watts) in contests. It seemed worthwhile to consolidate these into one article, making it easy for others to use if they so choose. This information is even useful for the large majority running more power, since many hams live in cities in circumstances where antenna constraints can make their operating results similar to QRP. That is, whether your power is low or your antennas are small, the operating challenges are much the same.

In part I am doing this since I recently pulled these points together to provide input to someone soliciting input for a forthcoming magazine article on the subject of useful tips for QRP contesting. Summer is a good time for this since I am not doing much on my station, either operating or antennas. There are links below to earlier articles with more on particular topics. However you might still wish to use the search box since I made no effort to reference every relevant article.

Now let's see what I've got to say on the topic with my recent experience and modest success. There may be points you disagree with or others you believe I've overlooked. It should also be of use to QRPers only entering contests to add to their DXCC totals.

The best of times for QRP contesters

It's easier to do well in contests with QRP than ever before because there are more well-equipped large stations across the globe than ever before. Individual affluent hams and contest clubs have been building large stations by the hundreds all other the globe, at home and in the tropics. They want to work you. More than that: they need to work you. They did not put up multiple towers with stacked yagis to work each other; it isn't needed.

Motivated hams and clubs that build super-stations do it to win, and winning requires reaching the majority of hams with modest power and space-restricted antennas. We must only do enough on our end of the circuit to make that possible. Yes, there are hams that hate working the weak ones -- I've encountered a number of them -- but they and their opinions are irrelevant. They are losers. I don't use that word as a pejorative; those who won't work the weak ones lose valuable points and multipliers.

The winners make the effort needed to pull through everyone they can, whether a weak QRP signal or a weak signal from a rare multiplier on the other side of the world. There are many reasons why a signal can be weak -- propagation, distance, power, antenna, off the side of the yagi, among others -- and the wise contester doesn't stop to wonder why, they just work them.

Decide what you want to gain from this opportunity. If your objective is merely to have a little fun, test your equipment and skills, or to hunt some new countries you need do nothing special. However if you want to be competitive there are tactics that will help you toward that goal. You can do well even with the simplest of QRP stations.

Be a contester

Apart from power you must think and act like a contester. Don't be timid! Be aggressive and use all your skills and stations capabilities to their utmost, just like any serious contester. That includes computer integration, the biggest and best antennas you can manage, low loss coax, high CW speeds, logging software with message automation and more. The same tactics that aid the big guns will improve your results. You should also strive to constantly improve your skills.

When I say high CW speed I mean high 20s or even 30 wpm. Don't send faster than the other station but do keep the speed high. Experienced contesters will copy your QRP signal just fine. If their QRM is high or you're on the low bands and they have difficulty you should lower your speed as low as it takes to get in their log. On 80 and 160 I often find myself sending 20 wpm or lower on DX contacts. Return to high speed once that difficult QSO is completed.

Every decibel counts

There is a rule of thumb among the big guns that a major antenna investment doesn't truly pay unless it delivers an improvement of at least 3 db. In my opinion the threshold for the QRPer is lower: even 1 db makes a difference when your signal has a very small SNR at the other end of the QSO.

Do you have an inverted vee on 40 meters? Using a horizontal dipole at the same apex height will earn 1 to 2 db. An inverted vee is slightly directional so put up another at right angles to the first. Can you manage a small tri-band yagi or hex beam at even a modest height? That will gain you 3 to 5 db on the high bands. Do you use a vertical on 80? Double the number of radials from 4 to 8 and gain 1 or 2 db. The difference in casual operating may not be very noticable but in a contest you may be surprised how much it helps. Just a few more multipliers on 80 meters will make a pleasant bump in your total score.

Practice S & P

Let's face it, most of the time you will be hunting stations during the contest. So it pays to do it well. In the early part of the contest it is possible to achieve S & P rates of 3 QSOs/minute on CW and 4 on SSB when every station you hear is guaranteed to be a new one. It takes practice, hard work and it can be fatiguing. But it pays huge dividends.

Learn to copy and type in a call on hearing it the first time. Call anyway even if you don't have it copied perfectly; don't waste time. Aim to complete the QSO in seconds from the time the station is first tuned in. Correct or complete the logged call sign when you hear it the second time. Don't hesitate to ask for repeats of calls or exchanges if you're unsure. Otherwise you may have to hang around on his frequency longer that you might expect.

If the propagation or competition to get through to a station proves too tough you should keep moving. Most logging software includes a band map of self-spots or (if you're operating assisted) cluster and skimmer spots. When you hit the band edge start clicking and calling those stations again. It gets easier later in the contest when everyone's rate drops.

When you do operated assisted (many QRPers do so with great success) exploit the spots more in the first half of the contest than the last half. Early in the contest the big guns are running and have less time to respond to spots that are not attractive multipliers. So there will be fewer callers for you to deal with. Later in the contest when rates drop the big guns will quickly QSY to every spot that appears. You can't compete with them and you'll waste time if you try.

Run!

If everyone operates S&P no one would make any QSOs. Yet many casual operators and little pistols will only S&P. To work the perpetual S&P'ers you must run: sit on a clear frequency and call CQ. Run? With QRP? Yes! But you have to pick your times and places to be successful.

Don't try to run early on in a major contest. No one will hear you, or they will choose to work the hundreds of big guns before they'll try to ferret out your weak signal. I like to rename Sunday as Runday when I operate QRP. By then everyone's rate has dropped and there are fewer stations that the big guns (and even little pistols) haven't worked. Pick a place high in the band, though not too removed from the bulk of the activity and switch your software to run mode. Hit the CQ button. Do it again, and again. It may take a while to get results.

On CW a little persistence quickly pays off. There are dozens of skimmers around the globe that will hear your CQ and put your call on the screens of hundreds of stations hungry for QSOs. Within one minute you'll get callers. Some may not copy you well, or at all, so eager are they to get you in their log. Don't expect a high rate, perhaps only 1 per minute, so you may feel that you're wasting time. But by this time in the contest that's a better rate than S & P.

SO2R

Although I have not yet done a serious SO2R effort there are notable attractions to the QRP operator. This is not only a tool for the big guns to increase their scores.

First, let's face it: other than isolated instances the QSO rate of the QRP station is poor. Rather than get bored or frustrated consider filling that time by doing S & P on two bands at once or running on one band while S & P on another. If you only work one station every or two by running you have ample time to hunt down multipliers on another band. Or if you are camped out on a needed multiplier's frequency trying to get through the other callers you can easily S & P on other bands (or even the same one) with a second rig.

Second, the equipment requirements are less for QRP than other stations. You'll still need logging and station automation software, and the switching for antennas, headphones, keyer and mic, but not much else. The expense and complexity of band pass filters and harmonic-notching stubs can usually be omitted.

Consider that by running 5 watts you enter the game with -23 db of attenuation of cross-rig interference over those using a kilowatt. That's almost always enough to eliminate station interaction even with antennas that are almost on top of one another. Although you will still encounter harmonics (e.g. 14.004 MHz harmonic of a 7.002 MHz fundamental) you won't fry your receiver front-end.

In the case that you only have multi-band antennas (fan dipole, tri-band yagi, etc.) you'll either need to put up a one or two mono-band antennas or use diplexers on the multi-band antennas. I expect that most operators would not want to deal with the latter, especially in a QRP station. This may limit the bands on which one can operate simultaneously. Even with this restriction there can be ample opportunity to increase one's score doing SO2R part time.

Walk a few meters in the other operator's shoes

Often getting through with QRP in a contest requires an understanding of the other end of the QSO. Is it a time of day and frequency when QRM is a major factor for them; running a pile-up; a tropical station with strong atmospheric QRN; is the operator lazy or inexperienced, and so do you have to prod him into finding your signal and making the effort? These are questions to think about when you make your call and don't have immediate success.

Here is one example I've used before. Many stations use exceptionally good filters on CW, with narrow pass bands and steep skirts. The pass band can be unpredictable since you don't know the other operator's preference for high or low audio tones, and the RIT may have been left on from a previous contact. Zero beating could put your signal at the edge or even off the edge of his pass band.

If you run a kilowatt you can still be heard when the receive filter attenuates your signal. With QRP you won't be heard at all. Try shifting your frequency up and down 50, 100 or even 200 Hz and try again. Many times I go from not being heard to solid copy.

Here's a second example for working stations with a small to medium size pile-up. Unlike in typical DXpedition operations the callers in a contest almost always send their call just once. This has become typical since in a contest it is rare to operate split, so calling again only serves to cover up the DX station. But if your timing is impeccable and you are sure the DX answered no one you should quickly call a second time. Very often you'll be the only one calling and even with QRP you'll get through. Be quick though (up to 30 wpm on CW) or you'll only add to the QRM.

Propagation

When that needed multiplier is almost but not quite workable with QRP it pays to understand something about propagation enhancement. On the higher bands when the MUF begins to fall at either your or the other station's late afternoon/early evening there is a brief period when propagation is enhanced. It might only last for 5 or 10 minutes. Most logging software includes a world map of where the terminator lies (sunrise and sunset boundaries). Check back periodically and when the signal rises one or two S-units that is often enough to make the grade. But be quick because soon afterward the band will close in that direction.

On the low bands something similar occurs but this time at sunrise. On 80 meters I would note the time when the sunrise line crosses the Ural Mountains. Over the next several hours, one by one the east and then west European signals would in turn be briefly enhanced. That is often enough to convert a "?" reply into a solid QSO.

On 40 meters the enhancement is less but as the sun rises the propagation ceases to all directions except towards the receding night. That's towards North America from Europe, or toward the Pacific from NA. As daylight advances they can hear the weaker stations better due to less QRM and QRN, at least for a little while until the band closes for the day.

Another pattern from my QTH (VE3) is to the Caribbean on the high bands. As the skip lengthens in late afternoon or early evening (depending on solar flux) much of my competition in the US is at a disadvantage. Even with QRP that is a good time for scoring a few multipliers. In the opposite direction polar propagation to TF, OX and UA0 gives us a similar advantage, but in this case it is due to proximity.

The advantageous propagation patterns in your locale will be different than mine. Take the time to learn them throughout the year and exploit your knowledge in the contest.

Pick your contests

Especially as the solar cycle wanes and the QRP-friendly high bands become less useful it can be less frustrating to focus on contests that award points for in-country and in-continent QSOs. You might want to focus on those rather than the major DX contests. For example, WPX, IARU, NAQP, Sweepstakes among many others can put the QRP station in good stead on the low bands. With higher rates you're less likely to grow bored or frustrated.

Also, don't fear SSB contests. You'll do less well of course, yet there is much fun to be had. Give it a try.

Moving on

As I mentioned last year my time as a QRP contester is coming to an end. It's fun but not something I need to do forever. I have other plans. Hopefully a few of the tips I've given here and in earlier articles will help those who have an enduring passion for QRP and contests. I am not worried about telling my secrets (such as they are) since I enjoy sharing and I doubt that anything I've said is unknown to experienced contesters.

1 comment:

  1. Thanks so much for compiling this overview, including the links to your previous posts. It is a great resource for new hams, or returning hams such as myself.
    73, Steven N5NAA

    ReplyDelete

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