[RTTY] TX and RX not on same frequency

[Bob Darlington]

I double checked these settings, all looked okay.  Turns out there is an
option in the radio to flip what the fsk line does and that was set the
wrong way.    The clue was the jibberish coming in to fldigi.  Flipped it
and that was good to go.

The problem with the tx being offset from rx is an artifact (aka, bug) in
my software.  If I set my filter width to the native width of 400Hz, it's
wrong on the waterfall.  450Hz done through the DSP and everything is lined
up as you'd expect.  I'll email Tom (VA2FSQ.com) about it so he can get it
updated in the next version of Win4k3Suite.

Thanks all!

-Bob N3XKB

On Thu, Dec 22, 2016 at 2:21 PM, Bob Darlington <rdarlington at gmail.com>
wrote:

> Dave, thank you.   This makes sense, and it jives with what I just read in
> the manual.  I've been trying to figure this out for the last several days,
> off and on, and just came across a topic in the manual, "I transmit on a
> different frequency from my receive frequency when I operate FSK".  Yep,
> sounds like my problem indeed.
>
> Much thanks,
> Bob
>
>
>
> On Thu, Dec 22, 2016 at 2:17 PM, Dave Hachadorian <k6ll.dave at gmail.com>
> wrote:
>
>> 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
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>
>