bpnjensen wrote:


Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? (FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. The thing never even gets warm.

On Feb 14, 2:32*pm, dave wrote:
bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? *(FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). *Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, *and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. *The thing never even gets warm.

That's reasonable I think. You'd need to amass in the neighborhood of
100-120 watts demand before you'd require roughly an ampere of
current, and that should be just barely cruising for the SS-12.

bpnjensen wrote:
On Feb 14, 2:32 pm, wrote:
bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? (FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. The thing never even gets warm.

That's reasonable I think. You'd need to amass in the neighborhood of
100-120 watts demand before you'd require roughly an ampere of
current, and that should be just barely cruising for the SS-12.

The radio uses about 3 Amps on transmit. The amplifier about 5.

On Feb 14, 5:32*pm, dave wrote:
bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? *(FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). *Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, *and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. *The thing never even gets warm.

From Astron website I conclude: SS-XX series are switching
power supplies. Great for heavy loads, usually stay cool,but... not
perfect enough for me. They generate RF,even the better ones. The
ones that were designed for the so-called 'TEMPEST' program probably
exist, somewhere. Receivers designed with TEMPEST requirement must be
around as well. Somewhere. Otherwise,there is no readily available
substitute for a regulated linear power supply. This was recognized
long time ago.

wrote:
On Feb 14, 5:32 pm, wrote:
bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? (FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. The thing never even gets warm.

From Astron website I conclude: SS-XX series are switching
power supplies. Great for heavy loads, usually stay cool,but... not
perfect enough for me. They generate RF,even the better ones. The
ones that were designed for the so-called 'TEMPEST' program probably
exist, somewhere. Receivers designed with TEMPEST requirement must be
around as well. Somewhere. Otherwise,there is no readily available
substitute for a regulated linear power supply. This was recognized
long time ago.
My antenna is 30 feet away. The switch mode power supply noise is
well below what is ambient at that location.

Linear supplies waste energy. I can leave my switcher on all the time
and I don't have to worry that it is wasting energy.

On Feb 15, 1:10*am, wrote:
On Feb 14, 5:32*pm, dave wrote:

bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? *(FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). *Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, *and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. *The thing never even gets warm.

* * * * From Astron website I conclude: *SS-XX series are switching
power supplies. Great for heavy loads, usually stay cool,but... not
perfect enough for me. *They generate RF,even the better ones. *The
ones that were designed for *the so-called 'TEMPEST' program probably
exist, somewhere. Receivers designed with TEMPEST requirement must be
around as well. Somewhere. Otherwise,there is no readily available
substitute for a regulated linear power supply. This was recognized
long time ago.

I am familiar with the TEMPEST program but not what we're talking
about in this thread - interesting.

On Feb 16, 3:37*pm, Bob Dobbs wrote:
Gregg wrote:
On Feb 15, 1:10*am, wrote:
On Feb 14, 5:32*pm, dave wrote:

bpnjensen wrote:

Is it safe, then, to assume that a combination of draws that total
somewhat less than the lower rating would not put undue stress on the
supply? *(FWIW, I'm still thinking the Astron 7/5 amp supply for my ~
2.5 amp max needs, or if I feel unsure, the Astron 12/9). *Might even
throw a muffin fan on the back.

Gentlemen, thanks for all your great help!

Bruce

I run a 12 Watt radio (K3/10), my LDG Z-100 tuner, *and a 45 Watt amp
(Tokyo Hy-Power HL45B) on an Astron SS-12. *The thing never even gets warm.

* * * * From Astron website I conclude: *SS-XX series are switching
power supplies. Great for heavy loads, usually stay cool,but... not
perfect enough for me. *They generate RF,even the better ones. *The
ones that were designed for *the so-called 'TEMPEST' program probably
exist, somewhere. Receivers designed with TEMPEST requirement must be
around as well. Somewhere. Otherwise,there is no readily available
substitute for a regulated linear power supply. This was recognized
long time ago.

I am familiar with the TEMPEST program but not what we're talking
about in this thread - interesting.

The TEMPEST operation I'm somewhat familiar with concerned detection of monitor
or keyboard emissions to determine what was displayed or typed, never thought
about listening to PS noise to try and determine the action of a connected
device.

--

Operator Bob
Echo Charlie 42- Hide quoted text -

- Show quoted text -

Any power supply has a signature. Should be visible on a
good scope. Linear types normally don't create any RF harmonics. The
TEMPEST program is an extreme example of suppressing ALL unwanted
radiation. Whether from keyboards,oscillators in radio equipment and
especially power supplies. The most important part of all electronic /
electromechanical apparatus. Low level signals (audio and rf ) could
be affected by switch mode p.s. That's why it is highly desireable to
install coax to the antenna. RF emenating from almost every gadjet we
use today is a big headache . Some very sucessful high end audio
designs implement a separate power supply for EACH stage . And none of
them seem to favor switchers!

wrote:
Some very sucessful high end audio
designs implement a separate power supply for EACH stage . And none of
them seem to favor switchers!

They probably don't have to buy their own electricity. If I was still
using my 2 [ea] 9 Amp linear supplies my electric bill would be $100 a
month higher. I got the switcher to save energy. The fact that it is
tiny, quiet, and cool is all gravy.

There's an electric motor at a quarry, over a mile away, that has some
sparky brushes. I can tell when they turn it on and off. This is a
very quiet (QRM) spot.

On Feb 17, 5:24*am, dave wrote:
wrote:
Some very sucessful high end audio
designs implement a separate power supply for EACH stage . And none of
them seem to favor switchers!

They probably don't have to buy their own electricity. *If I was still
using my 2 [ea] 9 Amp linear supplies my electric bill would be $100 a
month higher. *I got the switcher to save energy. *The fact that it is
tiny, quiet, and cool is all gravy.

There's an electric motor at a quarry, over a mile away, that has some
sparky brushes. *I can tell when they turn it on and off. *This is a
very quiet (QRM) spot.

I had exactly this same problem last week when a bunch of guys about a
half mile away were doing road work with a compressor. The noise
level from that mess was an intermittent 20 over S9, and the MFJ-1026C
had a hard time wiping it. Thank goodness they're gone.

On Feb 17, 9:58*am, Bob Dobbs wrote:
bpnjensen wrote:
The noise
level from that mess was an intermittent 20 over S9, and the MFJ-1026C
had a hard time wiping it.

Next time try repositioning your sense antenna.

--

Operator Bob
Echo Charlie 42

I guess I could have - but both antennae are suspended well above my
roof, and I work days ;-)