WB2WIK
Member
Posts: 20004
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« Reply #1 on: December 13, 2004, 09:25:38 AM » |
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"Noise?" If you mean radiated or conducted wideband emissions that can be heard in sensitive ham receivers, switch mode power supplies are guaranteed more likely to generate such interfering noise than linear power supplies. However, some of the popular "ham radio" switching power supplies are very quiet, as they've been designed and manufactured to minimize this problem, with the knowledge that the power supply *will* be connected to ham gear.
The power supplies sold by the major manufacturers as accessories to their equipment (Icom, Kenwood, Yaesu) are switching type power supplies, almost without exception nowadays. The reasons are long and varied, but in general, a switch mode power supply is not only lighter, but can also cost less to manufacture and be designed as "universal input," so a single power supply model can be used all over the world without changing anything except the plug on the end of the cord. You can't make a "linear" supply like that cost-effectively.
The Astron RS-70M is a good, solid linear supply. I've had one in my shack for many, many years and absolutely never shut it off. Last time it was "off" was when I moved, over four years ago. Likely next time it will be "off" is when I move again, unless there's a utility power failure in the meantime.
WB2WIK/6
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