Re: [Discuss-gnuradio] How to use IQ Bal Optimize/Fix?

[Marcus D. Leech]

On 01/31/2018 03:16 PM, Sylvain Munaut wrote:
> Hi,
>
> * You can just use 0.0 / 0.0 as the default. Those value are only
> really used if you don't use the message system and just want a fixed
> / known manually set correction. Once the first message is received,
> those value are overwritten
>
> * As stated the time constant is in samples.
>
> * The 'optimize' block only really works when you have some narrow
> band signals distributed around the spectrums. It will fail
> _miserably_ if you have a single wideband signal centered around DC
> ...
>
> Cheers,
>
>       Sylvain
Indeed, I find that if I use the osmocom IQ-balance code on radio 
astronomy "signals" that it produces horrible results in interferometry 
applications, as
  it never really "converges", and adds significant long-time-scale 
phase-noise, so I disable it.