Rich, Thanks for the explanation. I sure thought I could get FSK keying with the LP-Bridge but I understand what you are saying. I was using USB SignaLink with a modification to a FSKit circuit published in QST a few years back for FSK keying of my Icom Pro III and it worked well. I have used AFSK before but Still prefer FSK so I guess it's back to getting it all set up again. 73, Earl, K4KAY
-----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Richard Ferch Sent: Wednesday, October 21, 2015 2:59 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3s on rtty You cannot use the same serial port for CAT (rig) control and FSK keying. The reason has nothing to do with COM port sharing between parallel rig control applications, which is the issue LP-Bridge solves. The fundamental issue is that FSK keying and CAT control use the RS-232 signal lines in incompatible ways. You must use a different serial port for FSK keying than the one you use for CAT control, and no port-sharing method (LP-Bridge, com0com, VSPE) can change this. LP-Bridge will allow you to use two rig control programs in parallel, but it will not allow you to use one serial port in two fundamentally incompatible ways. For FSK keying you need a one-transistor switching interface between the RS-232 voltage levels (plus and minus 12V) on the COM port you are using for FSK and the FSK keying input (pin 1) on the K3's ACC connector. If you don't already have an FSK keying circuit, it would be easier to use AFSK with MMTTY. From the operator's point of view, AFSK A on the K3 is almost indistinguishable from FSK D. The K3's transmitted signals using AFSK are just as clean as its FSK. In fact, until relatively recently the K3's AFSK was cleaner than its FSK. And with AFSK, no special keying circuit is necessary. Indeed, if you are using the K3S's USB port for rig control, I believe no new cables are needed at all. Just tell MMTTY to use the sound card inside the K3S. If you were using a SignaLink before, that was AFSK. You do not need the SignaLink with the K3S, because everything it does is already provided for inside the K3S, but apart from changing the sound card MMTTY uses, there should be little difference between using the SignaLink and using the K3S's internal sound card. 73, Rich VE3KI K4KAY wrote: > From Earl, K4KAY. I now have lp-bridge running and cat control is working > fine. I have to give credit to my friend Richard, K4KRW for his help. > > > > I am now trying to get MMTTY going and reading other posts about using > transistor to invert the signal etc, to do FSK. I have done this with > > Other rigs but also remember others saying I no longer need the signal link. > Which rtty program would be simpler. I already have MMTTY on > > My computer and not successful on my first try. I assume I would use the > lp-bridge to get it on the K3s but when I assign the comport on the > > Lp-bridge MMTTY tells me I have no comport. > > > > I am open for suggestions. I prefer MMTTY but can go another route if > simpler and I want to stay with FSK with my K3s and P3 panadapter with the > VGS option. > > > > Regards, > > Earl, K4KAY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to efort...@ctc.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
