Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

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.

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

On Feb 15, 4:35*am, Bob Dobbs wrote:
Gregg wrote:
On Feb 15, 12:41 am, Bob Dobbs wrote:
Gregg wrote:
I just wish the CB Newsgroup wasn't trashed like it is.

Just ignore all the homophobic flames
and post as if you're the only person there.

--

Operator Bob
Echo Charlie 42

I should take your advice Bob. I do - from time to time go over there
and lurk and it seems like there are no threads about CB/Antennas,
there used to be some pretty informative (at least for IMO) threads.

OK, I'll put an antenna related post up over there.

--

Operator Bob
Echo Charlie 42- Hide quoted text -

- Show quoted text -

Ha! That was funny. I'll check later on, make it a good one and we'll
see what happens.;-)

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

On Feb 15, 11:59*am, bpnjensen wrote:
On Feb 14, 9:52*pm, Gregg wrote:





On Feb 14, 3:10*pm, bpnjensen wrote:

On Feb 14, 11:29*am, "D. Peter Maus"
wrote:

On 2/14/10 12:15 , bpnjensen wrote:

On Feb 14, 7:15 am, "D. Peter
wrote:
On 2/14/10 07:11 , Gregg wrote:

On Feb 12, 11:29 am, "D. Peter
wrote:
On 2/12/10 10:13 , bpnjensen wrote:

Pyramids are not especially popular with the Amateur Radio crowd:

http://www.eham.net/reviews/products/20

So I have noticed! *But the Astrons, in general, have a loyal
following.

* * *I did some research into the Pyramid supplies. As I said earlier,
they were not built for continuous service. Apparently, at any load.
Shame, too. With modification, they can be a pretty decent supply.

* * *Apparently Pyramid has been taking design tips for ICOM.

* * *:)

Ah Ha then, maybe dear old former friend wasn't lying then about
modding them. He was always modding something when I was over at the
shop. *He sure wanted them back pretty bad. Tough. :-I

* * They're nice supplies. And as you pointed out, you DID work CB
off of one for a couple of years without issue. But that was
intermittent service, which is what most of these supplies are built
for.

* * Most any supply will work for most applications. It's continuous
draw that does them in. But that's not a surprise. ICOM's, like R71,
R7000, R7100 are renowned for running so damned hot that the back
panel can be too hot to touch. Even the factory recommends going in
periodically and touching up solder joints, checking components for
heat damage.

* * And ICOM"s not the only one. But that doesn't mean it's not poor
design.

* * Which CB rig were you running, and what type of antenna did you use?

Peter - Shouldn't a 5 amp output supply be fully adequate to support a
CB, even SSB, that would require a draw of maybe 2 amp at transmit?

* *That's the point....How is that 5 amps measured? If the 5 amps
was measured to be steady for, say 5 minutes, that's considered
continuous service. In the case of 2 way radio, 'continuous' may be
also considered anything that is not 'peak.'

* *The point then becomes 'how does the manufacturer define their
terms Peak and Continuous?' And how do they measure these services.

* *If the power supply is rated at 5 amps continuous, one may safely
assume that 2 amp draw will be no problem. HOWEVER, how is that 5
amp service measured? 5 minutes? 10 minutes? Or do they run the
supply until the components reach constant temperature and then rate
THEN measure the continous output for a week?

* *Probably not.

* *Most of the time, the supply is built for intermittent service as
found in 2 way radio service. Short bursts, a minute or more, of
sustained current at rated output. In this case, 5 amps. And the
supply does it handily. But the components never reach constant
temperature.

* *That same power supply may, if run at 2 amps, reach constant
temperature, and the components may not survive that temperature if
run continously, ongoing. Read the user reviews at eHam of supplies
that have burned up resistors, even though used within their defined
ratings.

* *Consider. You can take a CB radio out of the box, hook it up and
converse for an entire 1500 mile trip without difficult. The
components are taking the full rated output--peak and continuous--of
the transmission for the entire trip. In bursts of conversation,
sometimes a minute, two minutes at a time.

* *But that's intermittent service. Tape that key down and let it
transmit indefinitely. It will fail. And pretty quickly. The
components were rated sufficiently for peak current during voice
peaks, and continous current during a conversational segment, but
not for continous broadcast. Neither the power input regulators, not
the finals will take a full load indefinitely. Even though current
can be many times average. Even though the power throughput never
exceeds rating.

* *The radio used for conversation will be trouble free for years.
Used as a broadcast device, it will fail quickly.

* *Pirates like to use Ham rigs for their broadcasts. These have to
be modified for the duration of a broadcast to meet the extremes of
continous ongoing service. Even rigs built with conservatively
rated, quality components will not be able to meet the demand of
continous ongoing service. Though the same rigs will be in use all
day, every day for 2 way conversation without issue.

* *It all depends on HOW the power supply ratings are determined.
Very few are tested with continous ongoing service in mind. Because
that's not what they're purchased for.

* *So, that 5 amp rating may be illusory. And though 2 amps may seem
logically assumed to be a safe, and troublefree, output for a 5 amp
supply, if the components were selected with intermittent service in
mind, they may find that 2 amps takes them more slowly to constant
temperature, but they do reach constant temperature, where they sit
and cook until they fail because they're not sufficiently cooled.
And because the supply is built with intermittent service in mind,
component cooling is less of a priority, and not a design
consideration beyond the minimums.

* *That's why when selecting a power supply, current ratings are
usually meaningless unless you know how they were determined.
Assumptions may be made, but you have to know what assumptions the
manufacturer was making as well when the device was designed.

* *Read the eHam reviews of some of these supplies. Failure after a
short time at current draws well within the performance curve.

On the Astron supplies, near as I can tell, the high rating (the amp
value implicitly included in the model number) is the 50% duty value,
which I assume is what it can more or less safely handle if you switch
evenly between a high draw (such as during transmit) and a lower value
during receive. *The lower value Astron lists, which is typically
about 20-25% below the top value, is what the company claims is the
continuous amount it can safely provide continually.

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- Hide quoted text -

- Show quoted text -

I have to ask you post - - what is a "muffin fan"? Is it external or
internal?feeling like a big old dumbey

Just a little fan, about 7cm x 7cm +/-, usually about 12v or so, used
normally for cooling PCs but good for other small cooling tasks as
well. *RS has them for $15 if you need one in a hurry, but they can
be had many places on- and off-line for (much) less. *If you got one,
you'd probably just fasten it over the heat sink on the back.- Hide quoted text -

- Show quoted text -

Gotcha

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

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!

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

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.

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

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 ;-)

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

I have an old power supply thingy here, I bought it at a Goodwill store
a bunch of years ago.I am looking it over right now.It says on the metal
plate on the front,,,

Acme ACME Electric Corporation CUBA, NEW YORK VOLTROL MADE IN U.S.A.
TYPE T-8350 INPUT 115 VOLTS 50-60 CY. OUTPUT 6 AMP MAX.PATENTS NO'S
2009013 2061452

The device is HEAVY!, must have a HEAVY coil inside, I reckon.There is a
large round knob with a metal pointer underneath the knob and around the
perimeter of the knob, 70 80 90 100 100 (I did not mistype that, 100
100) 110 LINE 120 130

At the bottom left hand corner there is a toggle switch for ON OFF.In
the middle above the metal plate with the knob there is a meter/gauge
which says VOLTS A.C. 0 30 60 90 120 150.At the top right hand corner of
the device there is a round plug socket.
There is a handle mounted on top of the device.
I plugged it into a wall outlet.I think it works A OK.Of course it is
A.C.Voltage only.
cuhulin

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

On Feb 17, 8:26*pm, wrote:
I have an old power supply thingy here, I bought it at a Goodwill store
a bunch of years ago.I am looking it over right now.It says on the metal
plate on the front,,,

Acme ACME Electric Corporation CUBA, NEW YORK VOLTROL MADE IN U.S.A.
TYPE T-8350 INPUT 115 VOLTS 50-60 CY. OUTPUT 6 AMP MAX.PATENTS NO'S
2009013 2061452

The device is HEAVY!, must have a HEAVY coil inside, I reckon.There is a
large round knob with a metal pointer underneath the knob and around the
perimeter of the knob, 70 80 90 100 100 (I did not mistype that, 100
100) 110 LINE 120 130

At the bottom left hand corner there is a toggle switch for ON OFF.In
the middle above the metal plate with the knob there is a meter/gauge
which says VOLTS A.C. 0 30 60 90 120 150.At the top right hand corner of
the device there is a round plug socket.
There is a handle mounted on top of the device.
I plugged it into a wall outlet.I think it works A OK.Of course it is
A.C.Voltage only. *
cuhulin

Sounds like a Variac...a big rheostat or something. With some
testing, you could probably bring old tube rigs back to life slowly
(warm up and reform the capacitors...)

Recommendations - 12 / 13.8v Power Supply, ~ 5 amp?
 

On Feb 17, 11:26*pm, wrote:
I have an old power supply thingy here, I bought it at a Goodwill store
a bunch of years ago.I am looking it over right now.It says on the metal
plate on the front,,,

Acme ACME Electric Corporation CUBA, NEW YORK VOLTROL MADE IN U.S.A.
TYPE T-8350 INPUT 115 VOLTS 50-60 CY. OUTPUT 6 AMP MAX.PATENTS NO'S
2009013 2061452

The device is HEAVY!, must have a HEAVY coil inside, I reckon.There is a
large round knob with a metal pointer underneath the knob and around the
perimeter of the knob, 70 80 90 100 100 (I did not mistype that, 100
100) 110 LINE 120 130

At the bottom left hand corner there is a toggle switch for ON OFF.In
the middle above the metal plate with the knob there is a meter/gauge
which says VOLTS A.C. 0 30 60 90 120 150.At the top right hand corner of
the device there is a round plug socket.
There is a handle mounted on top of the device.
I plugged it into a wall outlet.I think it works A OK.Of course it is
A.C.Voltage only. *
cuhulin

It is known as a 'Variac', may I interject.