I have been using an Alinco DM-330MVT switching supply with my FT897D at
home. It has a knob that allows you to change the switching frequency
slightly to move any birdies you may experience off your receive frequency.
But the only time I have experienced any birdies from the supply on receive
has been while listening to MF, LF or VLF signals. I have not heard
anything on HF or VHF using this supply. It is very good.
Zack W9SZ
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On Mon, Nov 11, 2024 at 9:21 PM Charles Gallo <charlie@thegallos.com> 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@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@alum.mit.edu
> > @bdj_phd
> >
> >> On Mon, Nov 11, 2024 at 10:17 AM Charles Gallo <charlie@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@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@gmail.com>
> >>>> To: CQ-Contest Reflector <cq-contest@contesting.com>
> >>>> Subject: [CQ-Contest] 12V 30A Switching Power supply recommendation?
> >>>> Message-ID:
> >>>> <CACUWneMbC3gksLzOC4Yn3XoEsbKagd-D07Cy94G7B43oaninTw@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
> >>>>
> >>>>
> >>>>
> >>>
> >>> --
> >>> This email has been checked for viruses by Avast antivirus software.
> >>> www.avast.com
> >>>
> >>> _______________________________________________
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> >>> CQ-Contest@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/cq-contest
> >>
> >>
> >>
> >> _______________________________________________
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>
>
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