Wall Wart Question

[BOBRR]

Hi,

Re those cheap switching wall-warts:

Is 2.5-3.5 MHz, or so, a typical or expected frequency range for the pulse noise they
emit ? Or, usually, much higher ?

Happy Holidays,
B.

 

[a417]

Hi,

Re those cheap switching wall-warts:

Is 2.5-3.5 MHz, or so, a typical or expected frequency range for the pulse noise they
emit ? Or, usually, much higher ?

Happy Holidays,
B.

they might concentrate around their switching frequency, and then splatter harmonic noise everywhere. There is no surefire way to tell where their noise will end up, sadly. You can look at the schematic of the particular device you have (if avail, or you want to pop the top) and try to decipher it...or you can plug it in and see where it creates garbage.

 

[BOBRR]

Hi all,

As I've written about, I am plagued with 2 to 3 MHz noise pulses.
Hard for me now at my age to do all the disconnect and re-connect routines.
So, I am willing to replace my switching cheap wall-warts with a linear, non-switching, "something".
Assuming that the noise is from these wall warts, but, frankly, 2 to 3 MHz noise pulses seems to me to be quite low for these units to be emitting ? Thoughts ?

The APC and CyberPower UPS are obvious choices, but I really don't need
the battery backups. If we lose power, the last thing I would want is to play with is my SDR's.

So, what do I want that would be linear, and similar to the UPS units, but without
the battery backup feature ? Also, very concerned about posts that mention the battery bursting
into flames ! Would need around a 1 KW (not VA) unit, or perhaps a bit more.

*Or, for "clean" linear non-switched power, a battery in a unit is really required for what I am after ?

Any brand and model suggestions would be most appreciated.

Best regards, and a most happy holiday,
Bob

 

[a417]

What are your output voltage requirements?

If it's all 12-14vDc, I would recommend an Astron Linear power supply (or similar), they have a long and distinguished record of being reliable and electrically quiet supplies.

 

[BOBRR]

Hi,

Thanks.
Will look at the Astron units.

Best,
Bob