[Elecraft] RTTY Problems on K3

[Larry (K8UT)]

Bill,

You could begin by breaking the problem in half - test at the output of 
the optoisolators.

Front Half - Test what's coming from N1MM and MMTTY:
Put a scope or meter on the PTT line and click [TX] in MMTTY. Does the 
line go low and stay low for the duration of TX?Put a scope or meter on 
the FSK line and click [TX] in MMTTY. Does the line toggle at 15ms RTTY 
intervals? With a meter the voltage would drop, indicating lower average 
voltage - but something would be different between RX and TX.
 >If this doesn't work, first place to check is the MMTTY >Options >Setup 
 >TX, "PTT and FSK" and >MISC, "Tx Port"

Back Half - Test whether the K3 is sending RTTY:
Use a clip lead to short the optoisolator PTT output to ground. Does the 
K3 go to TX?While the K3 is still in TX, use a second clip lead to short 
the optoisolator FSK output to ground. Does the TX monitor tone shift?
-larry (K8UT)

------ Original Message ------
From: "k3sv at pa.net" <k3sv at pa.net>
To: Elecraft at mailman.qth.net
Sent: 2020-05-24 1:12:45 AM
Subject: [Elecraft] RTTY Problems on K3

>I am fairly new to the K3 but have no problems setting up N1MM and  other software, getting things to work properly. My problem is I  cannot get RTTY to send/TX. I have made a homebrew interface with  optoisolators for both the FSK line and the PTT line. I'm going from a  separate serial port, pins 3 and 7, for FSK and PTT, to the Assy(15  pin) connector. To pins 1 for FSK, 4 for PTT and 5 for ground.
>
>When I run MMTTY I cannot get the rig to key. If I switch to SSB or CW  and use the CAT line to work the PTT, no problem. If I switch to RTTY  and try to use the CAT line it will not key the TX. I've tried a  variety of setting in MMTTY and get no TX. I have a 1000MP set up with  a similar homebrew interface and have no issues.
>
>Can anyone shed some help on me?
>
>73 Bill K3SV
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Elecraft at 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 k8ut at charter.net