I need a linear 5V 1A PSU. The switch mode versions interfere with the radio receiver it is to power.
I have been unable to find such a thing.
Does anyone know of a suitable item?

 

What are you willing to pay.

5AB150-230 Acopian Power Supplies | AC DC Converters | DigiKey Marketplace

This is something I would probably build myself.

 

Not sure what form you want but there are plenty of 230V to 5VDC linear PSUs on AliX. Lowest I see are ~15W though unless you go for a wall wart.

 

Ebay has some listed for sale but, of course, it's caveat emptor buying from them.

If interested, building you own could be done with a 6Vac, 2A (transformer needs near 50% derating) or 12Vac center-tapped, 1A transformer, with rectifiers, filter capacitors, and an LM317 or LM7805 regulator on a heat-sink for a near "bullet-proof" supply.

 

I need a linear 5V 1A PSU. The switch mode versions interfere with the radio receiver it is to power.
I have been unable to find such a thing.
Does anyone know of a suitable item?

This used to be a typical hobby project back in the 70s, mostly of the variable voltage kind. I have an ICOM IC-R75 receiver, bought it twenty five years ago. I have a large yard now, over an acre, so I can run long wires all over the place but to my extreme sadness all I can hear is noise and I think it's from the plethora if fixed mode supplies around my home, TVs, fridges, computers etc.

I'd love to get to the bottom of it all one day.

 

Not sure what form you want but there are plenty of 230V to 5VDC linear PSUs on AliX. Lowest I see are ~15W though unless you go for a wall wart.

It is difficult to tell whether they are linear or switching though.

 

I have ordered the parts to build one.
Thanks all.

 

I have ordered the parts to build one.

Out of curiosity, what are the parts you ordered?

 

These are what I ordered. Gives me the minimum work to do. The 7805 module includes a rectifier too.
https://www.ebay.co.uk/itm/388016987496
https://www.ebay.co.uk/itm/283080696959?var=583482246928
https://www.ebay.co.uk/itm/365965709529

 

These are what I ordered

So I presume you will connect the the 4.5Vac transformer output windings in series to prove 9Vac to the 7805 module.
Note that will generate about 11.2V rectified and filtered DC to the 7805 so will generate about 6W dissipation of the 7805 for a 1A output.
That may make that small heatsink pretty hot.

But since the transformer is rated at 6VA, you likely can output more than about 0.5Adc without overheating the transformer.
Or did you buy the 12VA version?

 

One of the first projects I built as a student.






transformer
bridge rectifier
LM7805
capacitors
power cord
strain relief
switch
fuse
LED
resistor
case

 

So I presume you will connect the the 4.5Vac transformer output windings in series to prove 9Vac to the 7805 module.
Note that will generate about 11.2V rectified and filtered DC to the 7805 so will generate about 6W dissipation of the 7805 for a 1A output.
That may make that small heatsink pretty hot.

But since the transformer is rated at 6VA, you likely can output more than about 0.5Adc without overheating the transformer.
Or did you buy the 12VA version?

The rectifier will lose 2 diode drops from the rectified voltage and the 1 amp is an overestimate so I think it will be OK.

 

The rectifier will lose 2 diode drops from the rectified voltage

I included that in my calculation.

 

I included that in my calculation.

I didn't check your arithmetic.

 

I purchased about 25 of the 120/240 volt linear regulated 5 volt power supplies long ago. BUT the output current was "up to six amps" . Isolated Linear Regulated five volt power supplies are commonly availabe from most HONEST electronic parts distributors, at least here in the USA. Those supplies may not be "cheap", and most of them are rated at more than one amp. At least one honest supplier has been mentioned.

 

Linear PSUs in the exact 5V/1A spec can be tricky to find off-the-shelf since most manufacturers have shifted to switch-mode for efficiency. A few options worth checking:

Look for "linear regulated" wall adapters specifically (not just "linear" — some sellers mislabel switch-mode units) from brands like CUI, Triad Magnetics, or Jameco's house brand — they still stock genuine linear supplies for exactly this kind of RF-sensitive application.
Alternatively, building your own with a simple 7805 linear regulator + transformer is straightforward if you don't mind assembling it.