Topband: 5V 3A Wall Wart Recommendations?

Joe Subich, W4TV lists at subich.com
Wed Feb 26 09:42:02 EST 2025


On 2025-02-18 4:04 AM, Michael Tope wrote:
> This outfit sells AC-DC linear wall warts:
> https://www.acdcpowershack.com/collections/ac-dc-linear-power-supply

Unfortunately, they have nothing at 5V.  I have a whole tub of
linear wall warts I've saved from other devices over the years -
everything from 6, 9, 12, 18 and 24V but nothing at 5V 3A.

To wrap this up, I found a 5V 4A switcher on Amazon that specifically
claimed "No EMI" and showed what appeared to be compliance documents
for CE and the FCC.  At $14.99, I picked up a couple of them and they
do appear to be quiet and my daytime noise levels are back down to
the -115 to 125 dBm range (a 35-40 dBm improvement on 80 and 160m)
on transmit antennas - typical suburban noise levels.

Here's the link to the quiet supply in case anyone is searching in
the future:

<https://www.amazon.com/GOOKYO-Charger-Switching-Replacement-Adapter/dp/B0BD72BWBK> 


73,

    ... Joe, W4TV

On 2025-02-18 4:04 AM, Michael Tope wrote:
> This outfit sells AC-DC linear wall warts:
> https://www.acdcpowershack.com/collections/ac-dc-linear-power-supply
> 
> I recently procured one to replace the Jameco wall-wart for my SAL-30 
> receive antenna. When listening on the SAL-30, I found that strong 
> stations had sidebands something like 1 KHz away (I don't recall the 
> exact offset, but it rendered the antenna virtually useless when the 
> band was crowded with strong signals). Switching to my Astron variable 
> linear supply cured the problem. When I looked at the output of the 
> Jameco wall-wart on an oscilloscope it was making several volts of 
> ripple, so I chucked it and I got the 15V DC @ 1000mA supply with 2.5 x 
> 5.5mm (+) center polarity connector from the ACDC Powershack. It is 
> unregulated so the open-circuit output voltage was 19.6 Vdc, but under 
> load the output of the SAL-30 bias-tee is around 12.5 Vdc. As far as I 
> can tell, the SAL-30 is just as quiet on the new linear wall-wart as it 
> was on the Astron.
> 
> 73, Mike W4EF..................
> 
> 
> On 2/17/2025 5:08 PM, Joe Subich, W4TV wrote:
>>
>> Having just begun a noise mitigation project, I've found
>> two of the biggest sources to be a pair of wall warts for
>> the USB hubs attached to my radio and office computers.
>> Removing them dropped the noise floor by 20 dB on both
>> 160/80 (and by about 10 dB on the other bands).
>>
>> Does anyone have a recommendation for a source of *quiet*
>> replacements (preferably with 3.5 x 1.35 mm coaxial plug)?
>>
>> 73,
>>
>>    ... Joe, W4TV
>>
>>





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