[RTTY] TX and RX not on same frequency

Dave Hachadorian k6ll.dave at gmail.com
Thu Dec 22 16:17:41 EST 2016


With K3 in RTTY mode, hold PITCH button, and observe the mark 
frequency.  In MMTTY options/setup/demodulator tab, choose the 
exact same mark frequency. Turn off MMTTY AFC.


Dave Hachadorian, K6LL
Yuma, Arizona


-----Original Message----- 
From: Bob Darlington
Sent: Thursday, December 22, 2016 1:49 PM
To: RTTY Reflector
Subject: [RTTY] TX and RX not on same frequency

Hi guys,

I'm new to RTTY when it comes to using an FSK interface.  AFSK, 
easy peasy
and I've done it off and on for years.

I recently purchased a W3YY interface board, soldered it up, got 
it mounted
in a box and then cabled to my rig.

I'm running an Elecraft K3S radio using MMTTY software (either by 
itself or
through N1MM+).

In addition to this I'm running Win4k3Suite for the panadapter 
display.

What I see is that I can decode rtty just fine.  If I try to 
respond to a
CQ my transmitted signal is next off by a bit.  I can see it on 
the
panadapter that I'm not in the same column, so to say, but 
instead off by
several tens of Hz or more.

This gap seems to depend on the filter setting in the rig.   I'm 
using FSK
D (data) mode for all these tests.   I just can't seem to get it 
to work
right.   I randomly found a webpage that said to push the "HAM" 
button to
get the tx and rx to align.  I don't know why these would drift 
apart, but
I bit and saw no improvement.  It did snap the mark frequency 
back to 2125.
   I figured I should turn off AFC.  I still have this problem, 
but the
mark frequency doesn't drift around as the software tries to 
figure out the
rtty signal frequency.

What am I doing wrong?   I feel like the little waterfall display 
and band
scope in MMTTY is just off by a bit and don't know how to correct 
this.
It's listening to the wrong frequency I think, but am unsure how 
a filter
change on the rig would change this.  I'm not attempting to use 
the double
peak rtty filter, although when I have tried, it doesn't seem to 
make any
difference.


All that said, I also see that I am MUCH faster at pouncing on 
signals
using fldigi with AFSK signalling so may participate in the RTTY 
Roundup
that way.

Thanks for any suggestions,
Bob - N3XKB
_______________________________________________
RTTY mailing list
RTTY at contesting.com
http://lists.contesting.com/mailman/listinfo/rtty 



More information about the RTTY mailing list