Re: [Linrad] i/q calibration

[Leif Asbrink]

Hello Pf,

Something is wrong with your hardware. The Q signal is missing.

73

Leif / SM5BSZ



> Hello,
> how much signal should be enough for the I/Q calibration? The calibration screen says A/D(0) = 80% (more or less) and A/D(1) = 0 %. There's a line saying signal too weak, and the graph never turns green.
> What I'm missing?
>
> Pf, ik5pvx
>
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Leif Asbrink <le...@sm5bsz.com>

[Pierfrancesco Caci]

Hello Leif,

well that's explained with the cold solder that finally gave up shortly afterwards. Thanks.

On a related note, I had to use "channel_delay = 0" in quisk, which if I understand correctly means I-channel is delayed by 1 with respect to Q. Did I guess it right that I need to use "Sample shift [-1]" to achieve the same in linrad, or is it the other way around?

Pf

 Pierfrancesco Caci, ik5pvx

[Leif Asbrink]

Hello Pierfrancesco,

I do not remember whether you would need +1 or -1.
Use trial and error. You will see immediately on the
I/Q balance which would be good very near the center
for -1,0 and +1 but that will stay reasonable as you
move away from the center for only one value.

It would take more time for me to look into the code
to find out...

73

Leif

[Pierfrancesco Caci]

Thanks Leif,

I'll do trial and error :-)