Roy, A bit of explanation may help:
When you transmit using FSK D, your RTTY program generates characters in the 5-bit Baudot (Murray) code at 45.45 bps and keys the FSK keying line to send that code by shifting the transmitter's frequency between two frequencies 170 Hz apart. PSK31 uses a completely different code (called Varicode) with variable-length characters sent at 31.25 bps, which is used to modulate a single frequency using phase-shift keying. The PSK31 software that is commonly used with other radios generates PSK31 at audio frequency in a sound card, needs an audio cable between the sound card line out and the K3's line in, and uses the K3's DATA A mode. I know of no application software that generates Varicode on a keying line instead of using an audio signal. If you use an RTTY program to key the radio in PSK D mode, no-one will be able to decode it because as far as I know there is no software available to decode Baudot characters modulated using phase-shift keying. According to the help file, the K3 Utility can send PSK31 by sending ASCII characters to the K3 over the RS-232 cable. In PSK D mode the K3's firmware converts from ASCII to Varicode and phase-shift modulates the transmitted signal. This would require no additional interfacing other than the serial connection, although it would not actually use the cable you have connected to the ACC port. Note as well that in all three cases (FSK D, PSK D and DATA A), the normal way to receive data signals without additional hardware is by decoding audio with a sound card. The audio cable from the K3's line out to the sound card line in is all you need to do this, and provided your software is capable and set properly for the mode being decoded, you can use this same setup to receive in all data modes. In FSK D and PSK D the K3 is also capable of doing the decoding in the radio and sending the data to the computer as ASCII over the RS-232 cable, but other than the K3 Utility there is no software available to use this capability as far as I am aware. 73, Rich VE3KI K3 #1595 WK4Y wrote: I have a digital question. I am using the ACC port on the K3 to do RTTY (FSK D). I have a box that was made for me with the appropriate parts for this function. The cable with the box from the ACC is connected to a com port on the computer. Also I have a audio cable (Stereo) connectors on each end going from the Line out of the K3 to the Line In on my desktop computer. It works very well on RTTY. I decided to try PSK, and have tried the following method without success. Since theis cable worked with RTTY in FSK-D I thought it should work for PSK. I tried the same setup with the K3 with DATA MD set to PSK-D 31 bps. I am able to transmit a signal but I have been told there is no printout on the receive end. Any help is appreciated. Thanks, Roy - WK4Y #1366 _______________________________________________ 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
