[Elecraft] RFI on K3s

[Dave B]

Cant help thinking, that the charge to discharge "Efficiency" is probably no better than a good linear PSU, but you do I guess get the "Off grid" option for EMCOM work..

There ARE (RF)quiet SMPS's out there, but not priced in a way that will suit the average Ham's budget.   You get what you pay for.  Oh, and they tend to be large too, due to the filtering.

Quite honestly, for "Amateur" work, where the rig will usually spend most of it's life in RX, a linear PSU is just fine.   Plus, you can fix them when things fail.   Try that with a modern well suppresed QRO SMPS!..

73.

Dave G0WBX.


~~~ Original message.

From: Marc Veeneman<mveeneman at yahoo.com>
To:pubx1 at af2z.net
Cc:elecraft at mailman.qth.net
Subject: Re: [Elecraft] RFI on K3s
Message-ID:<768828B9-AF69-479E-8E38-2FBEEC234B0F at yahoo.com>
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My PowerWerx supply DOES generate those drifting noise spikes, ruining CW on 80 meters for me.  I have yet to find a 13.8 volt switching supply that can provide 25 quiet amps.  I've gone entirely to batteries rather than use quiet but inefficient linear supplies.

  Now I only have SMPS noise when recharging the batteries.  So I leave that for non-hamming hours.  More testing is needed, but I did find one SMPS for LiFePO4 batteries that seemed RFI free.  It's an Optimate brand product but only produces 5 amps.