[CQ-Contest] Switching Power Supplies

[Jeff Blaine]

Ferrites are your friend in cases like this.

And for a fellow who has a shack/antenna 25' away, ferrites are 
something probably found in abundance already in his shack.  At that 
distance so many metalic things want to get involved in the noise 
generation game or dream of being parasitic elements or diodes and other 
than adding distance, ferrites go a very long way in calming down the crowd.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 11/11/2024 7:35 PM, Charles Gallo wrote:
> No,
> My comment was more along the lines that in the quarter century since that article, I’m sure there are many new models of supply, that it is entirely possible that internally models have changed. It was really really great information on what existed 25 years ago, but how good is it on what exists today?
>
> Reading a lot of the EE trade bags, particularly over say the last 4-5 years, EMI/RFI has become a big topic for switching power supply folks, and the chip makers that now make chips specifically for power supplies have done work to help eliminate some of the issues, and heck, even the printed circuit board design software folks are putting in features to help eliminate the issues.
>
> So yes, great article on what was the state of the ham radio industry at the turn of the century, but how much it reflects today is up for debate
> --
> 73 de KG2V
> Charlie
>
>> On Nov 11, 2024, at 8:04 PM, Barry Jacobson <bdj at alum.mit.edu> wrote:
>>
>> Hi Charles, wasn't sure if you were addressing my comment. But thanks
>> for the very informative QST article. Wasn't sure what feature you
>> were focusing on, but if you look at the spectral plots, all but one
>> or two have noise issues in the ham bands. That review is from 2000.
>> Maybe things have improved since then, and you could post a more
>> recent article. I would be curious. Personally, my hearing is very
>> poor so I wouldn't want to take a chance unless I knew for sure the
>> model is noise free. Others may not mind for the convenience of better
>> portability.
>>
>> Best of luck.
>>
>> Barry WA2VIU
>> --
>> Barry Jacobson
>> WA2VIU
>> bdj at alum.mit.edu
>> @bdj_phd
>>
>>> On Mon, Nov 11, 2024 at 10:17 AM Charles Gallo <charlie at thegallos.com> wrote:
>>>
>>> You think that maybe, just maybe, there are new things, and things have changed in nearly a quarter of a century?
>>> --
>>> 73 de KG2V
>>> Charlie
>>>
>>>>> On Nov 11, 2024, at 7:57 AM, Ed Goss <ed.n3cw at gmail.com> wrote:
>>>> Barry:
>>>>
>>>> See:
>>>>
>>>> http://www.radiomanual.info/schemi/ACC_powersupply/Power_supplies_review_QST_2000.pdf
>>>>
>>>> --Ed, N3CW--
>>>>
>>>>
>>>>> Message: 2
>>>>> Date: Sat, 9 Nov 2024 18:44:49 -0700
>>>>> From: Barry W2UP <w2up.co at gmail.com>
>>>>> To: CQ-Contest Reflector <cq-contest at contesting.com>
>>>>> Subject: [CQ-Contest] 12V 30A Switching Power supply recommendation?
>>>>> Message-ID:
>>>>>    <CACUWneMbC3gksLzOC4Yn3XoEsbKagd-D07Cy94G7B43oaninTw at mail.gmail.com>
>>>>> Content-Type: text/plain; charset="UTF-8"
>>>>>
>>>>> Looking for a recommendation for a 30A 12VDC switcher.  No RFI is very
>>>>> important as my antenna is only about 15-20 ft away from the station.
>>>>>
>>>>> Tnx,
>>>>> Barry W2UP
>>>>>
>>>>>
>>>>>
>>>> --
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