Re: U3S Deluxe WSPR intermodulation products


geoff M0ORE
 

Many wall plug type power supplies don't have much smoothing built in and rely on the unit being powered to clean up the supply. 7805 regulators are not the quietest devices around and can cause noise problems if not fully de-coupled correctly. Why do you need two or three of them. I have never seen more than one in use. One will supply 1 A and if more current is needed, then a series pass transistor such as a 2N3055 can boost the current. A LM 317 variable voltage regulator is much quieter and can also supply 1A again followed by a transistor to boost the current avaliable.
For a really clean supply, look at http://www.wenzel.com/documents/finesse.html .

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