QRPp or milliwatt QRP - Keynote # 4, 1999
This month, I'm going to talk about QRPp. No, that's not a typo. It's a term used by CQ magazine, among others, to designate the QRP category in their contests. Why they don't simply use QRP, I don't know, but that's another story. The term QRPp is also widely used among the QRP community to designate QRP at the milliwatt levels, i.e. less than 1 watt.
Most of the time I will use my full 5 watts output when I am on the air. However, now and then I do enjoy QRPp. In the early part of 1996, I did quite a bit of it, working 31 states and some 25 countries with 500 milliwatts or less. My best QRPp contact was probably working Aruba with just 70 milliwatts.
After that, I got away from QRPp again until early this year. With the improved conditions brought on by increasing sunspots, I decided to crank down the screen voltage on my 6Y6 final amp and do some operating with 500 milliwatts again.
I met with success as I worked about a dozen states so far, including WY, AZ, MD, MT, and WA to bring my overall total to 36 worked. I've also worked some more DX including RW2F, KG4BV, V31RC, and LY2GF.
When you run with milliwatt power, what are some tips for success? Well, as I have said before, tips for successful QRP work are just tips for success at any power level. Probably the lower in power you go, the more important it becomes to zero beat exactly as the first place a station listens after a CQ is exactly on his own frequency. If you are there, you are more likely to be found than if you are a half kHz or more higher or lower in frequency.
I get many of my milliwatt QSO's from calling CQ myself. That kind of ensures that I am strong enough to be copied if someone takes the time to answer my CQ. Again, I DO NOT use /QRP after my call. That is just my personal preference, and not a guideline. If you are going to answer someone's CQ, it is a good idea to pick out a good strong one. That way, it is likely that propagation between you and the calling station is good enough to support your milliwatt power level.
I recently received a propagation prediction program, and I may talk more about it in a later column. The literature with it pointed out an interesting fact that is sometimes overlooked. The best conditions for communications between two points occur when the Maximum Usable Frequency (MUF) between those two points is just above the operating frequency. Even more importantly, when operating at those optimum conditions, power level is not really all that important, and the low power operator can have as great a success as someone operating with much higher power.
That's a rather important paragraph, so let me go over it again with an illustration. Suppose I am interested in working a station in Oregon, and I am in Pennsylvania. Either from a propagation program or some other source of propagation info, I find that the MUF between PA and OR is 22.5 MHz at 2000Z for the current solar flux level of 190. Now don't check those figures - I just pulled them out of the air for this example. They may or may not be accurate. However this means that I have a good chance to work the OR station at 2000Z on 15 meters since the 15M band is just below the MUF between PA and OR at that time.
So consider the propagation conditions when you are working with milliwatts. It can help.
One of the cinch ways to succeed with QRPp is to get into contests. This is something I haven't done all that much yet. Most of my QRPp contacts have come from regular QSOs. Why contests, you may ask? Well, many contest stations have the absolute best receiving equipment and antennas in the world and they can copy very weak stations perfectly that a regular operator with average equipment and antennas may not even hear.
I've talked about how transmitting antennas can boost your QRP ERP tremendously. Well, that works in reverse, as well. The contest operator with a stacked array delivering 13 db of gain will copy your 500 milliwatt signal as if you are transmitting with 10 watts. And if you are using an antenna with a gain of 13 db with your 500 milliwatts, that same station will copy you (if your arrays are pointed at each other) as if you were running, let's see, 200 WATTS!!!!
Those of you who follow my activities and this column regularly know that I am a QRP minimalist, i.e. I use only unity gain antennas and keep my ERP close to my actual power output. I say this so that you realize that you don't have to have big antennas to succeed with QRPp, although if you do, it certainly will help you.
Finally, something I think is very important. I believe, along with many others, that to be counted as a QRPp contact, the QSO must be initiated with QRPp. That is, if you contact someone with 5 watts, then later in the contact you reduce your power to 500 mW, that contact counts as a 5 watt QSO, NOT a 500 mW QSO. Whatever power you start with is what counts for that contact.
So if you get to the point where working with 5 watts gets to be too easy for you, I hope you'll give QRPp a try. If you do, be sure to let me know of your accomplishments and I'll share them here in my column.
Remember, you can get in touch with me at John Shannon, 478 E. High St., Kittanning, PA 16201-1304 -or- via Email - or - home.windstream.net/johnshan/. Till next month, 73. -30-