Lucky wrote:

wrote in message
ups.com...
Lucky wrote:

Hi Ron

I heard switching supplies are not the best choice for radios. But I
don't
know enough about them to really know. So you're putting fuses on the
hot
wire {+}coming off the PSU to the radio??

Lucky
---------------------------------------------
They may have improved swith mode power supplies in the last
few years. But my experience has been that they produce a LOT
of RF noise. Sinc ethe local RF noise almost always set the limits
for reception, you can't receive singals lower then the locla noise
floor,
it is weel worth the erffort to keep my house as RF "clean" as I can.

And using a switch mode to power my radio gear is at odds with
receiving weak signals. I have friends who use switchnmode supplies,
and mounted them in faraday cages with extensive fitlering for the AC
mains and DC output. Even a well built linear/analog supply can need
some additional bypass caps to really quiten it down.

If I were going to use a switch mode, I would be sure to have an
arrangement to retrun it if it was too noisy.

Another point for me is linear supplies will last much longer due to
their passive nature. Switch mode supplies have electronic switches,
ether bipolar or FET transistors that fail with suprising regularitly.
At the
electronic facility where I work, we have linear supplies that are over

30 years old. None of the switchers last any where near that long. And
anyone can repair a linear supply if it fails, switchmode supplies are
much more complex and when they fail are very dificult to repair.

Terry


Good morning Terry.

Based your real world experiences, it sounds better to stick with linear
PSUs for now at least for me. I don't have the know how Ron has to make sure
it all works right with a switching PSU if there is any added problems. I
like to eliminate any potential problems that might occur if I have a
choice. I just want to listen to the radio, not build faraday cages

Lucky

Hi Lucky

I have an Astron SS-30m. It's a switching power supply, and I've had no
problems with RFI.

I've never been fond of switching power supplies, but I'd read some good
reviews, and decided the fact it's smaller and much lighter than a similarly
rated linear supply made it worth a try. (I have a bad back)

It was a good decision.

I found it on ebay a couple years ago, new in box for roughly $100.

I figure it'll handle just about anything I might need other than jump starting
a car.

They also make an SS20m. It probably would have met my needs, but the price on
the larger one was right, and I figured extra capacity meant it would probably
run cooler and last longer. I've yet to notice mine running above room
temperature.

Regards,

Mark