The RTTY or Digital filters are available on the newer versions of "firmware" and allow a complete set of filters tuned and setup specifically for RTTY or digital modes, however they must be enabled. The manual explains this Or if you have an older K2 with an upgraded MCU then you need to look at the newer manual.
The major point is that - 1. it is almost impossible to get any of the narrower filters within 1 Hz of the main (OP1) filter that is used for transmit in all cases regardless of which filter is selected. 2. The PSK program will transmit a tone equal to what the PSK program thinks is the received signal frequency - however, that is off frequency by 1 to as much as 20/30 Hz. from the actual received frequency when ANY filter is used other than OP1 because the K2 switches to OP1 in transmit. (The offset can be observed by tuning in a solid carrier and switching filters.) 3. If the other Party has AFC turned on then he will now transmit at that new frequency and thus the drift or actually frequency starts walking up/down the band. If you don't have AFC turned on then you will continue to transmit at the same frequency, unless you reset the signal to the new frequency. If at least one of the two parties involved does not have AFC turned on then Drift is less likely to happen. There is a small amount of drift in the K2 (less with the Temp Stabilizing MOD) from cold start for about 15 - 30 Minutes. Thus the above discussion assumes that 1. you have the temp stabilizing mod installed and 2. the rig has been on for about 30 minutes. Rich ---------- Oh, good point. I forgot to mention that I was using FL4 which was specifically set up for 1000 Hz center frequency and 700 Hz bandwidth. I thought that FL4 was specifically set up for digital modes. Does that mean "other" digital modes like RTTY and that PSK31 should be run with OP1 instead? Mark, NK8Q _______________________________________________ Elecraft mailing list Post to: [email protected] 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
