[SADXA] FT8 Frequency Measurements

[Wes]

Actually, it is an output.  Your sound card is supplying an audio signal to your 
SSB radio.  If FT8 is using CAT control, and you have Split on, FT8 might change 
your VFO during TX and adjust the audio frequency commensurately to minimize 
harmonic distortion in the passband.

Wes


  On 7/5/2018 10:45 AM, Richard Solomon wrote:
> No idea, I just trust to faith that the
> spectrum in FT8 has some meaning.
>
> BTW, it's not an output per se. It's
> a point on a frequency spectrum.
> Much like if tuned the radio up 1 KHz,
> my signal should appear at 1 KHz
> on the spectrum.
>
> 73, Dick
>
> 73, Dick
>
> On Thu, Jul 5, 2018 at 10:10 AM, Wes <wes at triconet.org> wrote:
>
>> Are you sure that FT8 is outputting 2 kHz?
>>
>>
>> On 7/4/2018 6:10 PM, Richard Solomon wrote:
>>
>>> It was a slow day today, so I
>>> decided to measure my XMT
>>> Frequency on FT8.
>>>
>>> Now, my Frequency Counter
>>> (HP 5334B) derives its reference
>>> frequency from a GPSDO, So I
>>> am rather confident in my readings.
>>>
>>> I set my FTDX-5000MP readout
>>> to 24.911 MHz and my Transmit
>>> frequency to 2,000 Hz in FT8.
>>> That should put me on 24.913.
>>>
>>> BUT, my counter read 24.912 ??
>>>
>>> I think it's an artifact of setting
>>> the mode to USB/PKT, but I
>>> find nothing in the manual that
>>> discusses that.
>>>
>>> I verified the radio is OK by loking
>>> at my XMT frequency in CW Mode
>>> and it was right on.
>>>
>>> There is a menu item (087) that
>>> I need to look at, maybe diddling
>>> that will fix the problem.
>>>
>>> Until then, I'll set the radio to + 1KHz
>>> when I operate FT8.
>>>
>>> I presented this on the WSJT site,
>>> but no response yet.
>>>
>>> Maybe I am wrong, but I don't
>>> think so.
>>>
>>> 73, Dick, W1KSZ
>>> ______________________________________________________________