It's my opinion that originally when switcher power supplies came out,
they were noisy. This gave them a bad reputation which they no longer
deserve. The current switcher supplies are now mostly very good and
produce almost no RF noise.
Carl Moreschi N4PY
121 Little Bell Dr.
Hays, NC 28635
www.n4py.com
On 9/8/2012 10:56 AM, Bob McGraw - K4TAX wrote:
I'm most often and usually always perplexed at the comments regarding
the use of switching power supplies. I have 4 that are used at my
stations and my bench on a regular basis. One being a 3200 VDC @ 1 amp
switching supply that is used for the VHF and UHF amp.
With my installation and grounding technique employed, operating the
Omni VII or the Eagle from a battery, and turning any of these supplies
on and off, I can not observe any noise increase on any of the HF bands.
These are Astron and Lambda 202a supplies.
I contend that my approach to grounding or bonding is the reason for my
success with these switching supplies. And I must say that my approach
is not near as extensive or complex as most hams seem to employ. The
antennas are wire center fed with balanced feed line or coax for HF and
yagi designs with hard-line feeds for the VHF and UHF antennas.
All switchers are not created equal, some are really nasty but do
understand that does not apply to all of them. Yes, see the ARRL test
results and evaluations. This however is not the total picture. I know
some or many folks do not agree with my approach and suggestions on the
topic of grounding , bonding and such. The only concrete position I take
is "mine works!"
73
Bob, K4TAX
----- Original Message ----- From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Saturday, September 08, 2012 1:39 AM
Subject: Re: [TenTec] TenTec Digest, Power Supplies
Jim, that's why the league tests switcher power supplies for trash.
All you have to do is read the reviews and buy a good one.
You always get trash when you buy cheap, no matter what it is!
73,
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of N4be_Jim
Sent: Saturday, September 08, 2012 4:03 AM
To: tentec@contesting.com
Subject: Re: [TenTec] TenTec Digest, Power Supplies
I use only linear supplies where possible. I couldnt care less about
efficiency. Why? Ever listen to the trash a cheap switcher puts out on
HF?
Unless well designed and filtered, a switching supply will raise the
noise
floor several S units. Yes there are decent ones but i would rather not
worry about it. Yes TT makes decent switchers, such as for the Orion, but
ever hear one of those when the fan kicks in? In my area a great deal
of HF
hash in generated by all the cheap Chinese supplies that dont adhere
to our
EMI standards, but we still accept their imports. No I will take my
Astron
50 amp 12 vdc supply any day. It runs my O2 and Harris RF-3200E quite
easily while loafing along. Jim N4BE
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