[RFI] Non-switching wall warts availability?

[KD7JYK DM09]

"Keep in mind a linear wall wart will offer transformation to the lower 
voltage from a specific voltage input: think transformer winding ratio."

Yes.

"If it’s 110/115 VAC in and 12 V out, you’ve landed a transformer/based 
linear power supply."

Unless it's a switching mode supply, or even just a big resistor, they 
have the same specs, regardless of what's in the box.

"If you are offered a wide range of voltage in, say 110-240 VAC and 12 V 
out you have a switching power supply."

Unless it has a switch, or a jumper.  Also bear in mind, you can have 
multiple inputs, and outputs, even with linear wall warts.  You never 
what what it is, until you have it in your hand.

I started grabbing the linear stuff in the 90's when it was clear the 
switching supplies were destroying everything around them, 
communications-wise.  Average price is about a quarter, and I've got so 
many I think my property is starting to sink.  on the plus side, I have 
what I need, in about 1/10th volt increments from fractional volt to 
tens of volts up to several amps, for anything I may even want to do.

Hit up the thrift shops, many will give you crates of linear supplies 
just for the asking, since they are heavy and the average wall wart 
doesn't sell for years, they are happy someone will go to the effort to 
make them disappear.

Kurt