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SSB Contesting – I’m not quite there yet

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I rarely operate SSB in contests [or outside of contests]. There are many reasons for this. The bottom line is that for a very modest station (no amp, low wire antennas), a CW signal is likely to be copied better on the receiving end than an SSB signal. Plus it’s a lot more trouble to get the “best” audio levels on transmit for maximum effect on SSB.

A CW signal typically occupies around 200 hz of spectrum. Depending upon how fast or slow the keying, the occupied bandwidth varies. On the other hand, with most amateur radio equipment an SSB signal occupies around 2.7 khz (2700 hz) of RF spectrum, give or take a little depending upon whether you are using filtering on the transmit side to cut off the upper and/or lower ends of the audio spectrum.

If you have a 100 watt transmitter, more of your power is going to be used to produce a much narrower signal on CW versus SSB. The wider the RF signal, the more power you are going to need in order for that signal to reach the same distance.

For someone with good hearing, they can usually hear audio frequencies between about 300 – 3000 Hz. But there are certain areas within that audio spectrum where we hear better and where the audio is more intelligible on the receiving end under marginal conditions (weak signal, lots of QRM/QRN, etc.).

We all have differing voice ranges. The microphone we are using may not adequately pick up those audio frequencies that are most accentuated when we speak. The audio stages of the transmitter we are using may need to be tuned to produce the most power at the audio frequencies that are best heard on the receiving end under marginal conditions.

I have a stock microphone. I haven’t done any homework regarding the best audio settings in my FT-950 to tailor the transmit audio to my specific voice characteristics. A stock microphone usually doesn’t pick up the best of my voice characteristics. The stock hand microphone is inconvenient in a contesting environment because you have to pick it up and hold it in front of your mouth each time you speak, which means you do not have that hand free to operate the radio or type on the keyboard. It’s best to buy a high quality microphone with an element that can reproduce your voice well while at the same time accentuating those audio frequencies that are best for DXing/contesting and not accentuate those frequencies that are more difficult to hear on the receiving end. Ideally I’d have something like a Heil Pro Set (combination headphones and microphone) and a foot switch so that I can key up without using my hands and I can have good sounding receive audio while blocking out other localized noise in the room, etc. I actually have what I consider to be a great set of headphones already (Sennheiser HD-280 Professional), so I would likely want to get a good Heil boom mic / boom assembly / foot switch. Then I could change the audio settings on the FT-950 to respond most favorably to the audio it receives from the Heil Mic. This would allow for a nice audio response and the best “audio punch” to ensure I’m being heard as good as I can be heard on the receiving end.

If you don’t have your transmit audio optimized, you won’t drive your signal with much power. On my FT-100 with the stock microphone, it was all I could do to get 50-60 watts of RF out when I would speak into the microphone. And what I really want is to be able to get as much of that 100w of power out when I speak into the mic.

So for now, SSB contesting is not very good for me. CW is much more effective. I’ll do it, and I’ll probably do some SSB in the Ohio QSO Party on August 28th and will likely participate [for a while] in the NAQP SSB contest this coming weekend.

Written by Mike

August 19th, 2010 at 3:38 pm

Posted in Contesting

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