> is possible to imagine to work one of most important data mode contest with
> KX3 and 10W?
> Thanks, Camillo iz6gvc
Yes. Many stations use 10 watts or less for data modes, including in contests. Higher power will provide more contacts and greater distances, but good atmospheric conditions and effective antennas can make QRP sound like QRO.
You can use either audio-based data modes (KX3 DATA submodes "DATA-A" and "AFSK-A") or the KX3's built-in DATA modes (FSK-D and PSK-D). In the latter case, you don't even need a computer, necessarily. The KX3 will decode and display PSK31 signals in PSK-D mode, and narrow-shift (170 Hz) RTTY in FSK-D mode. You can also transmit in these modes by using a keyer paddle; the KX3 converts the CW to DATA. The CW message buffers will work, too.
KX3 Utility has a "Terminal" window that uses CW, PSK-D, or FSK-D along with your PC's keyboard. This provides a way to use these modes without a computer sound card -- just use the USB or RS232 cable that you normally use with KX3 Utility.
All of this applies equally to the K3/10.
I have operated in many RTTY contests with the KX3 running 5 to 12 W. Usually I program one message buffer with just my callsign, twice, and another with a contest exchange. When doing search-and-pounce operation, you'll very rarely even need to use the keyer paddle.
> Hi Wayne,
> my first doubt is that many OMs that I've asked this question have answered
> that the KX3 is less selective with big signals near the operating frequency
> respect to the K3.
> Is a fact or between this two great radio the difference is only on the
The K3 does have narrower roofing filters available. The KX3's CW/DATA roofing filter bandwidth is effectively 1 kHz (500 Hz after I/Q demodulation). The K3 has several narrower bandwidths available: 500, 400, 250, and 200 Hz. The 200-Hz filter is especially effective at rejecting close-in CW/DATA QRM.