On 24/03/2015 22:01, Guy G4DWV/4X1LT wrote:

Hi Guy,
> I understand that the RF gain slider is supposed to modify the 'InGain'
> parameter in wsjt-x.ini.
>
> It does not seem to here.
Are you certain that you are looking at the correct .ini file? If you 
have used to multi instance capabilities of WSJT-X where you can use the 
--rig-name command line option to allow more than one version of WSJT-X 
to run concurrently then the location of the .ini files are different. 
The default instance with no --rig-name option is located at:

%LOCALAPPDATA%\WSJT-X\WSJT-X.ini

If you start another instance of WSJT-X with --rig-name=rig2 then the 
.ini is at:

%LOCALAPPDATA%\WSJT-X - rig2\WSJT-X - rig2.ini

>
> Steps taken - Check ini file, close it. Open wsjt-x, move slider, close it
> and then check ini file again - no change. Do same again, same result.
>
> I an hearing JT65 signals that do not decode. They are not weak, but again
> not super strong. I was getting tips from a fellow ham and he suggested
> setting the RF gain mid way which should get an InGain value of 0.
>
> Have I been misinformed or is this unexpected behaviour?
Settings the Rx gain is essential to get best decoder performance. I use 
the following procedure:

1) set the gain slider to mid position,
2) adjust any system sound level controls to maximum (treat digital gain 
controls as attenuation i.e. the base setting is 0dB and reducing the 
level will introduce an element of distortion or error),
3) adjust the rig output level to get an indication on the orange 
vertical bar meter in WSJT-X below maximum for all received signal 
levels (do not expect the meter to drop to the bottom on no signal, 
receiver and band noise will normally be at a level of 20 dB or more),
4) if a suitable level cannot be attained, adjust any system level 
controls to get the required level,
5) if there are no rig or system level controls available or they do not 
adjust the meter level to the required point then adjust the gain slider 
in WSJT-X to obtain the required level.

If you have to set the WSJT-X slider to very low levels then you may 
need to add extra attenuation in the system elsewhere. This is because 
using digital attenuation controls in the extreme will introduce large 
quantization errors that will reduce the resolution of the decoder 
dramatically. If you have them, analogue level controls should always be 
the first step in gain control.

Once the gain settings are correct you should adjust the waterfall 
settings to get the best indication of weak signals without being 
swamped by background noise. While setting the waterfall gain and zero 
offset it is best to disable the "Flatten" feature as this will tend to 
counteract any changes you make. Do not adjust the the rig, system or 
gain slider to get the desired waterfall display otherwise you will lose 
the optimum levels for the decoder. There are sufficient adjustments in 
the waterfall gain and zero offset alone to get a good waterfall display 
from correctly adjusted receive gain settings.
>
> Mni tnx,
>
> 73 Guy G4DWV/4X1LT
>
73
Bill
G4WJS.

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the 
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
wsjt-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/wsjt-devel

Reply via email to