Topics

Spectrum display : visual offset #spectrum

Rick I2BRT
 

HI !

My setup :
  • FT-5000 (set for FRSK and to use high tones for RTTY)
  • IF OUT SdrPlay RSP2
  • Win4Yaesu (set to use RSP2 from IF out)
  • Navigator as FSK interface and soundcard
  • MMTTY
  • N1MM
All ok.

Just one thing I can't explain.
While in RTTY and perfectly tuned a station (mean : decode correctly and XY scope centered) the Spectum display seems to be centered just only around one of the tones.
"Visually" I would like to have the signal centered in green are (green verticals lines around mark and space).
Is there any place where I can try to adjust this ?

See image to better clarify what I mean 




Many thanks indeed
Rick I2BRT (formerly iu2fgb)

ve3ki
 

Based on the information in your screen shot, I believe that the frequency displayed on your rig's dial is 14088.01 kHz. If so, and if the rig is in FSK mode, then the two peaks in the spectrum/waterfall should be at 14087.84 kHz and 14088.01 kHz (the rig's dial frequency is the Mark frequency, and the Space frequency is 170 Hz lower). The vertical lines in the N1MM+ spectrum display window are placed on these two frequencies (the program uses the radio's dial reading to place the vertical lines).

The two peaks in the Win4Yaesu spectrum/waterfall display are 85 Hz higher than this, i.e. the labels in the Win4Yaesu display appear to be wrong by 85 Hz. The spectrum/waterfall data in the N1MM+ spectrum display comes from Win4Yaesu, and that is why the peaks appear where they do.

Is there a mode-specific IF offset setting in Win4Yaesu? If there is an offset setting in Win4Yaesu, it looks to me as if the setting for RTTY is wrong by 85 Hz. Try adding or subtracting 85 Hz to/from the setting in order to line up the spectrum peaks in the Win4Yaesu display so that the higher-frequency (Mark) peak is labelled with the same frequency in the Win4Yaesu display as the frequency you see on the radio's dial. If you do this, the two peaks in the N1MM+ spectrum display should fall on the vertical lines in the display.

73,
Rich VE3KI



On Sat, Nov 17, 2018 at 07:07 AM, Rick I2BRT wrote:
HI !

My setup :
  • FT-5000 (set for FRSK and to use high tones for RTTY)
  • IF OUT SdrPlay RSP2
  • Win4Yaesu (set to use RSP2 from IF out)
  • Navigator as FSK interface and soundcard
  • MMTTY
  • N1MM
All ok.

Just one thing I can't explain.
While in RTTY and perfectly tuned a station (mean : decode correctly and XY scope centered) the Spectum display seems to be centered just only around one of the tones.
"Visually" I would like to have the signal centered in green are (green verticals lines around mark and space).
Is there any place where I can try to adjust this ?

See image to better clarify what I mean 




Many thanks indeed
Rick I2BRT (formerly iu2fgb)

Rick I2BRT
 

HI RICH !
Many thanks for your fast response.

Yes, display frequency on the rig is 14088.01 (same is reported on N1mm).
Yes, FT5K is in RTTY mode (mean FSK) and so VFO should display Mark (carirer with 2125 Hz offest).
Yoy're right , Mark tone should be at 14.088.01 and space -170 Hz (RTTY-Lsb), 14.087.84
Based on this thoughts , I agee that N1MM is correctly drawing the lines on specturm display (while the peaks are wrong).
In Win4YAESU I see now that there is one "global offset" in Scope control panel.
Tried that.


Worked, it moves up/down the drawing of the spectrum.
Correction appears to be more then 170:2, close more or less to -140 Hz (strange… in not 85 I was think to 170 but maybe there are other variables in the equation).

However … I got two new problems now :-) 
I guess "Global offset" means "for every mode", so maybe now in SSB/AM it could be wrong (no mode offset in Win4Yaesu).
I guess the receiver Width passband on Win4Yaesu scope (the grey area) is now offset by my "Global offset"
Am I wrong ?
However I think I also need the help of the "other" TOM :-) mean va2fsq

Rick I2BRT.



ve3ki
 

N1MM+, MMTTY, DX clusters and most amateur radios in FSK mode use the Mark frequency; fldigi uses the centre frequency. Perhaps Win4Yaesu is aligning on the centre frequency instead of the Mark frequency. You'd have to check with Tim va2fsq.

73,
Rich VE3KI


On Sat, Nov 17, 2018 at 08:50 AM, Rick I2BRT wrote:
HI RICH !
Many thanks for your fast response.

Yes, display frequency on the rig is 14088.01 (same is reported on N1mm).
Yes, FT5K is in RTTY mode (mean FSK) and so VFO should display Mark (carirer with 2125 Hz offest).
Yoy're right , Mark tone should be at 14.088.01 and space -170 Hz (RTTY-Lsb), 14.087.84
Based on this thoughts , I agee that N1MM is correctly drawing the lines on specturm display (while the peaks are wrong).
In Win4YAESU I see now that there is one "global offset" in Scope control panel.
Tried that.


Worked, it moves up/down the drawing of the spectrum.
Correction appears to be more then 170:2, close more or less to -140 Hz (strange… in not 85 I was think to 170 but maybe there are other variables in the equation).

However … I got two new problems now :-) 
I guess "Global offset" means "for every mode", so maybe now in SSB/AM it could be wrong (no mode offset in Win4Yaesu).
I guess the receiver Width passband on Win4Yaesu scope (the grey area) is now offset by my "Global offset"
Am I wrong ?
However I think I also need the help of the "other" TOM :-) mean va2fsq

Rick I2BRT.