The original PSK31 implementation included an option for FSK31. Theoretically, PSK31 should provide a 2-3 dB improvement in signal to noise ratio over FSK31. In practice, it is necessary to back off the power amplifier by a few dB to keep from generating an excessively wide signal, whereas FSK31 can be run in a class C amp at full power (as long as your amplifier can handle transmitting a continuous carrier). This difference can negate the improved SNR of PSK31. Since may of the digital mode software products support FSK31, it would be an interesting experiment to test its efficiency in a real communication system.
A KX1 could trivially generate a FSK31 signal. Decoding it might require a more powerful processor, but is doable. The interesting question is how you interface the input and output to the operator. A display and keyboard would require a larger package or a separate module that plugged into a KX1. There are some small keyboards and displays that would work for this type of application. So perhaps we ought to ask Elecraft to make a small keyboard and display that would plug into a KX1 type radio and allow if to transmit and receive FSK31. It would even be a nicer option if you could plug it into a K2 and transceive both FSK31 and PSK31. -John KI6WX ----- Original Message ----- From: "wayne burdick" <[EMAIL PROTECTED]> However, it may be possible to operate the KX1 in any low-data-rate, dual-tone FSK mode. This is compatible with a class-C final amp, and should require only a firmware change. The KX1's key jack would serve as the data input/output port for connection to a computer. Unfortunately FSK (e.g. traditional RTTY) is not quite as popular as PSK31 for QRP use, even though good reliability is possible with some variants. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
