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Re: Downconverter noise




> Well, then I guess I stand corrected.  But it just doesn't make sense.
> If the d/c is at S5 with no antenna and no signal, then you are already
> at least 10 to 15 dB above the noise floor of your radio.  Does the
> noise actually go DOWN once the antenna is mounted on the dish and put
> in place?
>
> I can tell you that form my experience you do hear an increase in noise
> with the d/c on, but it certainly isn't enough to move the s-meter more
> than a unit or less.  It's certainly not 5 units.
>
> I'm confused..
>


Hello all,
   pretty much every dc I have used including high end ones like uek-3000 and 
db6nt's, will have noise... when you have something that has lots of gain 
your bound to have a increase, my original transystem dc had almost s9 at 3 
db per s unit,  adding the filter mod cut it to s7.

  No, the noise does not go down when you mount it on a dish... 
you set it all up and then point your antenna at cold sky,and then adjust your 
attenuator for S0, now your ready to play.....

How much noise you will see depends on the length and type of coax your 
hooking up, the n.f. of the dc,the gain of the rig,etc etc etc.

In Phil's case I would agree with Howard and suspect he has a problem 
somewhere if he is seeing no s-meter reading at all with a short piece of 
coax...

73
Kevin wa6fwf

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