On 1/20/2014 11:54 PM, Rick - DJ0IP / NJ0IP wrote:
What is the probability of us actually getting ANYTHING these days that is
properly-designed, and engineered ?
In an earlier post, I mentioned that I have several switching power
supplies that are quiet. I'll be a bit more specific. One is a Power
Werx unit designed to run a 100W transceiver. I bought it several years
ago for exactly the application that Ken Brown discussed -- to carry on
an airplane to PJ4 for a contest. Another is the wall wart that came
with a Tecsun PL660 receiver. Another is a 100A industrial unit that a
friend bought to run my Herc II that I loaned him for a DX trip, and
which he gave me when he returned the amp. I have at least one other
wall wart switcher in my collection that is pretty quiet.
The problem with most switching power supplies is that they generate
high frequency square waves internally, which are then rectified to
produce DC, and are built as cheaply as possible with no thought to RF
trash.
Along these lines, I recently added a small solar system to run my
shack, and had to investigate charge regulators and DC-AC inverters. I
found many products that were noisy, and a few that were not. A smart
buyer of ANY product does his/her homework BEFORE buying.
I continue to be amused by those who post to a reflector that they just
bought xxx product, and ask what others think of it. What are they
looking for besides ego gratification?
73, Jim K9YC
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