[amsat-bb] attenuator construction questions

["Mark L. Hammond" <hammond@xxxxxxxxxxxxxx>]

Hello all,

To receive AO-40, I'm using a DEM preamp into a modified Transystem 3733 
downconverter and BBQ style dish.  I'm getting about an S9+5 or S9+10 
"background" signal.  I'm interested in constructing an in-line attenuator 
to put between the downconverter and my TS-790A help bring this down to a 
reasonable level.  (yes, the 144 ATT in the rig helps, but I want more.)

I'm guess I'm showing my ignorance here, but how do I do the calculations 
to determine the circuit needed for various levels of 
attenuation?  Meaning, suppose I want an attenuator that achieves 15 dB of 
attenuation?  What about 12 dB, or 20 dB?  I've perused/searched my ARRL 
Handbook CD, but can't find what I need.

Instinct tells me it will probably only be resistors--I just don't know 
what values or how many, etc.

Any help is much appreciated.

73,

Mark L. Hammond  [N8MH]

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