[Ronja] Vacuum tube in Ronja preamplifier

[Karel Kulhavy]

On Mon, Oct 15, 2007 at 03:02:17PM +0200, J.D. Bakker wrote:
> >  >Fibre optic system doesn't have ambient light from the sun with 
> >the associated
> >>strong noise source.
> >
> >Indeed, but if the *sun* dominates, then receiver noise factor is not a big
> >deal ?
> 
> Sun noise doesn't necessarily dominate, see
> 
> http://www.pointless.net/pipermail/ronja/2006-August/009130.html
> http://www.pointless.net/pipermail/ronja/2006-August/009132.html
> 
> ie: daytime sun-induced shot noise is equivalent to ~ -43dBm.
> 
> >Then only fix is filtering / optical screening to lower sun optical noise,
> >is that not so?
> 
> That would be a good plan. I still hope to find the time to 
> experiment with gel filters such as are used by theater lightning 
> technicians.
> 
> Point remains that the current front-end is noisier and less 
> sensitive than necessary; IMHO a change of architecture (active 
> transimpedance amp versus the resistor that's used now) helps more 
> that going for a hard-to-get vacuum tube would.

OK make it more sensitive people will like you.

CL<
> 
> JDB.
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