Monday, May 4, 2009

Cousin QRM - Big Gun Tips #1

Some of you may be familiar with a column in a prestigious magazine written by Uncle DX. Uncle and I are distant relatives. But every family has a black sheep, and I guess I'm it, which is why Uncle and I rarely talk. But I have been asked to write about Big Gun tips that Uncle would never publish. So from time to time, I'll share my wisdom here on the Fi-Ni Report.


Big Gun Tip #1 - if more is good, even more is better. This applies not only to RF power, antennas, towers and lap dances, but also extends to other things that make your signal sound like a Big Gun. Top of the list has to be bandwidth. Those Exalted Single Sideband (ESSB) boys got it right here. Nothing says Big Gun like an SSB signal that is 6-8 kHz wide.  You need that wide audio response to let your melodious oratory roll, especially when you initiate a rag chew with a rare DX station during the middle of his pileup. You want everyone to enjoy your report to the DX that he's a good 58 today and was only 56 when you worked him yesterday.


Not everyone goes for the AM on SSB audio sound. Sometimes conditions are poor and you need some extra punch to break through the QRN (your Big Gun signal IS loud enough to break through the QRM, right?) . That's where compression, or audio processing, come into play. All HF radio have it now, so use it. Again, if more is good, even more is better.  Vince Lombardi expected his players to give 110%, there's no reason your modulation should be any less. With a little practice and adjustment, you can do a pretty good Dearth Vader impression, too.


Now, the more is good, even more is better philosophy isn't restricted to SSB. The cw brethren can also benefit from its application as well. First off is your keyer weighting. Changing from the standard 3:1 weighting can give your fist a distinctive sound that will make it stand out in a pileup. If you are careful you can emulate a bug fist. With care, you can get used to sending with a weighting of as little as 1.2:1, which sounds pretty much like a machine gun with a stutter, i.e. about 80% of all bug operators.  Advanced operators can even replicate the Lake Erie swing, but that takes quite a bit of practice. So what if other stations are constantly asking for repeats. The point is they hear you.


Sometimes during a cw contest the neighborhood gets a tad crowded. Even those 250 Hz filters aren't sufficient to keep the next door Big Gun from making your AGC thump. If you're fortunate enough to have a rig with adjustable keying rise time, you can use it to your advantage. Reduce the rise time as much as possible. A shorter rise time means a wider keying bandwidth (and you thought I was going against the more is good, even more is better philosophy). Those key clicks will help nudge your frequency neighbors up and down a  bit in order to give you some more elbow room. If their receiver can't handle the awesome power of your signal, it's not your fault.


Well, that's enough advice for today for you Big Guns. If any readers find my advice helpful, it is completely unintentional. If you like my advice, I'll be back. If not, I'll be back more often.


73, Cousin QRM

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