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Optimal FSK Offset question

 

W4TV and AA6YQ helped me reset my mark frequency in my K3 to 2125, after I had a problem where stations were saying I was off freq when responding. As part of that, I set the Optimal Offset Value for FSK to 2210. It had previously been zero.

I did an on the air test with a friend. When he tuned? me in for proper printing, I copied his test fine - and the reverse worked as well, so far so good.

However, now when I? click on a SC spotted RTTY station, my rig goes to a frequency that is about 2khz away from the RTTY station's actual frequency - seems like it is off by that Optimal Offset Value.

Is there a way to fix that problem?

73 John K3TN
[email protected]
 

What data sub-mode is your K3 in?

If it is in FSK D or AFSK A, the radio's dial displays the actual Mark frequency, not the suppressed carrier frequency, and you need to enter a correction in the Mark Offset box in WinWarbler's RTTY Config. That correction would be the negative of your audio Mark frequency, i.e. -2125 . A value of zero in this box would be correct if the rig's dial displayed the suppressed carrier frequency, as it would in LSB, USB or DATA A, but not in AFSK A or FSK D.

73,
Rich VE3KI


---In dxlab@..., <jpescatore@...> wrote :

W4TV and AA6YQ helped me reset my mark frequency in my K3 to 2125, after I had a problem where stations were saying I was off freq when responding. As part of that, I set the Optimal Offset Value for FSK to 2210. It had previously been zero.

I did an on the air test with a friend. When he tuned? me in for proper printing, I copied his test fine - and the reverse worked as well, so far so good.

However, now when I? click on a SC spotted RTTY station, my rig goes to a frequency that is about 2khz away from the RTTY station's actual frequency - seems like it is off by that Optimal Offset Value.

Is there a way to fix that problem?

73 John K3TN
 

Thanks, Rich - I have the K3 in FSK D, mark 2125, 170hz shift.

Maybe I just hit some bad spots, didn't do any RTTY this past weekend to check. Will keep looking.

73 John K3TN
[email protected]
 

John,

In WinWarbler's Configuration window, under the RTTY tab, make sure that in the dark grey areas you have the radio button for LSB in the FSK area selected, Xcvr Mode set to RTTY, *Mark Offset set to -2125*, Optimal Offset set to 2210, and the FSK Control set to the COM port you are using or EXTFSK).

Based on your reported symptoms, my guess is that you did not have anything in the Mark Offset box. If your mark is 2125, the Mark Offset must be set to -2125 and the Optimal Offset must be set to 2210.

73,
Rich VE3KI


---In dxlab@..., <jpescatore@...> wrote :

Thanks, Rich - I have the K3 in FSK D, mark 2125, 170hz shift.

Maybe I just hit some bad spots, didn't do any RTTY this past weekend to check. Will keep looking.

73 John K3TN
 

Maybe I just hit some bad spots, didn't do any RTTY this past weekend
to check. Will keep looking.
Entirely possible ... there are a lot of lids out there using software
that only supports USB and spot "dial" frequency for everything (PSK,
RTTY, JT65/JT9, etc.).

73,

... Joe, W4TV


On 2/23/2016 5:50 AM, jpescatore@... [dxlab] wrote:
Thanks, Rich - I have the K3 in FSK D, mark 2125, 170hz shift.

Maybe I just hit some bad spots, didn't do any RTTY this past weekend to check. Will keep looking.

73 John K3TN
 

Thanks, Rich - you seem to have nailed it. Mark offset was blank. First, I mistakenly set that to 2125 and now clicking on spots put me 4Khz off... Figured that out and -2125 puts me dead on.

73 John K3TN

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