[RFI] 48v DC Clean Power Supply

[Clay Autery]

More than likely, it is 48vdc for the POE function, and uses a buck 
regulator or similar internally to drop the voltage to something lower 
like 12vdc or 5 vdc (or both) to run the electronics.

______________________
Clay Autery, KY5G
(318) 518-1389

On 03/25/20 11:45, Chuck Gooden wrote:
> Jim,
>
> I am having the similar issue at ~3.588 Mhz  issue.   If you have a 
> small radio the noise should be readily found near this freq. It does 
> drift slightly when the switch is first turned on
>
> I replaces the supply for my Unifi US-8-60 switch with a 48V 3 amp 
> Linear open frame power supply(P/N HD48-3-A)  made by Condor that I 
> purchased on Ebay for $20.00.  The power supply made little if any 
> difference in my system.  There is apparently another switching supply 
> inside the switch to reduce the 48V to a lower voltage for the switch 
> circuitry.  Putting in a cheap netgear switch will fix the issue, but 
> I lose my POE to power my wifi access points.  Both of my Unifi 
> switches have this issue with a slightly different frequency.  I like 
> the Unifi network and am currently living with the issue at the moment.
>
> See: 
> https://www.ebay.com/itm/Condor-HD48-3-A-Power-Supply-Board-48v-DC-Output-30-Day-Warranty/303451909858?hash=item46a724aee2:g:vWQAAOSwaENd1qco:sc:USPSPriorityFlatRateBox!61107!US!-1
>
> I also have snap on #31 ferrites on all cables connected to the switches.
>
> After I get my other PC built and my NAS working and online, I planned 
> on contacting the manufacture of the issue and see what they can do.  
> I do nothink they will be able to do much though. So I may be forced 
> to replace the switches
>
> Please keep me in the loop if you find out anything.
>
> 73's
>
> Chuck K9LC
>
>
> On 3/25/2020 10:50 AM, Jim McCook wrote:
>> My neighbor is throwing RFI out that affects 15 and 10m bands.  We 
>> finally traced the source to a Unifi US-8-60 internet switch that 
>> uses a separate 48v power source.  Naturally it's a dreaded switcher, 
>> so he needs either a clean switching supply (if it exists!) or a 
>> analog supply.  I'm unable to find anything resembling a wall wart 
>> style.  Can anyone suggest a solution? These internet switches are 
>> showing up much faster now and represent a big potential problem, 
>> compared to the typical router operating at 5v with the 14.029 
>> noise.  Jim W6YA
>>
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