snip
A one farad capacitor can only supply one amp for one
second at one volt. Hardly worth the expense.

It can only prevent a voltage drop on the first few peaks
of a SSB modulated signal. It's usefulness would be almost
totally drained after speaking just one appropriate word, pointless.

Then there is not much point in using them in any kind of DC power supply, is
there? Of course there is. Do the math, Tnom:

Oranges and apples...............
P.S. you are a idiot for even equating the two


A good car battery has, on the average, an source impedance of around 0.01 ohms
(dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG
has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead
is grounded at 0 ohms. So the total source impedance at the input of the amp is
0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency,
that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source
impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks,
reducing the peak output by 50 watts or more. This is a type of soft-clipping
and can result in some significant AF -and- RF distortion. And that's not
considering the temperature coefficient of copper, which shows more resistance
as it warms up from carrying lots of current, making the situation worse.

Adding caps at the power input leads of the amp can significantly reduce the
source impedance of the power supply. It -can't- provide more power than the
supply is capable of providing,

But for how long........."Do the math"

but it -can- smooth the voltage ripple just like
in any other type of power supply. And what if the vehicle is running? Do the
math: If you have a 100 amp alternator (at 13.8 volts), it has a source
impedance of .138 ohms, which is significantly higher than the battery, so it's
not going to be much help. In fact, because it's going to be so heavily loaded,
it's going to introduce some ripple into the power lines, ripple that can be
reduced by using caps at the input of the amp.

How much capacitance is needed? There is no easy equation. There are a number of
factors, such as the source resistance of the battery and alternator, resistance
of the wire, ESR of the capacitors, average modulation percentage, PEP watts,
etc, etc. Because of the very low impedance required by the amp, low ESR is
paramount. Despite the advertised claims, the 'monster' caps usually have an ESR
of several ohms, much higher than is usable. Computer-grade electrolytics have a
much lower ESR. Using many smaller caps in parallel is better than one big cap
because the ESR is much lower. Those are just a few things to consider. But the
general rule is to keep adding caps until they no longer make any improvement.


I'm really suprised, Tnom. After all the times you have shot your mouth off and
been proven wrong on technical topics, you -still- haven't learned to think
before you speak. Maybe next time.


One thing I am not surprised at........You will ignore the facts, like
you normally do to flame the group or express your pseudo
theory.


Yeah...Right, A few farads will make a justifiable difference. You're
to funny.

In , wrote:

snip
A one farad capacitor can only supply one amp for one
second at one volt. Hardly worth the expense.

It can only prevent a voltage drop on the first few peaks
of a SSB modulated signal. It's usefulness would be almost
totally drained after speaking just one appropriate word, pointless.

Then there is not much point in using them in any kind of DC power supply, is
there? Of course there is. Do the math, Tnom:

Oranges and apples...............
P.S. you are a idiot for even equating the two

Then explain the operational difference between a power supply filter cap and a
cap placed across the input of a load. Duh....!!!

A good car battery has, on the average, an source impedance of around 0.01 ohms
(dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG
has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead
is grounded at 0 ohms. So the total source impedance at the input of the amp is
0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency,
that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source
impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks,
reducing the peak output by 50 watts or more. This is a type of soft-clipping
and can result in some significant AF -and- RF distortion. And that's not
considering the temperature coefficient of copper, which shows more resistance
as it warms up from carrying lots of current, making the situation worse.

Adding caps at the power input leads of the amp can significantly reduce the
source impedance of the power supply. It -can't- provide more power than the
supply is capable of providing,

But for how long........."Do the math"

......? I said it -CAN'T- provide more power than the power supply. Are you deaf?

but it -can- smooth the voltage ripple just like
in any other type of power supply. And what if the vehicle is running? Do the
math: If you have a 100 amp alternator (at 13.8 volts), it has a source
impedance of .138 ohms, which is significantly higher than the battery, so it's
not going to be much help. In fact, because it's going to be so heavily loaded,
it's going to introduce some ripple into the power lines, ripple that can be
reduced by using caps at the input of the amp.

How much capacitance is needed? There is no easy equation. There are a number of
factors, such as the source resistance of the battery and alternator, resistance
of the wire, ESR of the capacitors, average modulation percentage, PEP watts,
etc, etc. Because of the very low impedance required by the amp, low ESR is
paramount. Despite the advertised claims, the 'monster' caps usually have an ESR
of several ohms, much higher than is usable. Computer-grade electrolytics have a
much lower ESR. Using many smaller caps in parallel is better than one big cap
because the ESR is much lower. Those are just a few things to consider. But the
general rule is to keep adding caps until they no longer make any improvement.


I'm really suprised, Tnom. After all the times you have shot your mouth off and
been proven wrong on technical topics, you -still- haven't learned to think
before you speak. Maybe next time.


One thing I am not surprised at........You will ignore the facts, like
you normally do to flame the group or express your pseudo
theory.

Present some FACTS, Tnom. I dare you!



Yeah...Right, A few farads will make a justifiable difference. You're
to funny.

What's funny is watching you choke on basic DC power supply theory (pun
intended).







=============

"...but I admitted I was wrong, Like a man! Something you and QRM
have a problem with. You guys are wrong and you both know it and
are both too small to admit it."
---- Twistedhed ----

=============


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
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-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Well here is some of the specs supplied for a 1 Farad cap from the
manufacture.,

# Capacitance 1 farad,+/- 5%, 20-24 Volt Surge, 105'C
# Dia. 3.54" x H 9.65"
# E.S.R. (0.0016 Ohm) Frequency? I don't care it works for me. Good enough
for me to use on a SSB amp with a 8 ' run of cable. Like I found out it just
helps
in reducing the voltage nulls during the audio peaks, and reduces the sudden
voltage drops in the electoral system. For
$59 bucks it OK to do. That's what he asked and This was my answer.


"Frank Gilliland" wrote in message
...
In , wrote:

snip
A one farad capacitor can only supply one amp for one
second at one volt. Hardly worth the expense.

It can only prevent a voltage drop on the first few peaks
of a SSB modulated signal. It's usefulness would be almost
totally drained after speaking just one appropriate word, pointless.

Then there is not much point in using them in any kind of DC power
supply, is
there? Of course there is. Do the math, Tnom:

Oranges and apples...............
P.S. you are a idiot for even equating the two

Then explain the operational difference between a power supply filter cap
and a
cap placed across the input of a load. Duh....!!!

A good car battery has, on the average, an source impedance of around
0.01 ohms
(dropping 1 volt per 100 amps, which is a darn good battery). Ten feet
of #8 AWG
has a DC resistance of 0.0063 ohms, and we'll just assume that the
negative lead
is grounded at 0 ohms. So the total source impedance at the input of the
amp is
0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50%
efficiency,
that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since
the source
impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the
peaks,
reducing the peak output by 50 watts or more. This is a type of
soft-clipping
and can result in some significant AF -and- RF distortion. And that's
not
considering the temperature coefficient of copper, which shows more
resistance
as it warms up from carrying lots of current, making the situation
worse.

Adding caps at the power input leads of the amp can significantly reduce
the
source impedance of the power supply. It -can't- provide more power than
the
supply is capable of providing,

But for how long........."Do the math"

.....? I said it -CAN'T- provide more power than the power supply. Are you
deaf?

but it -can- smooth the voltage ripple just like
in any other type of power supply. And what if the vehicle is running?
Do the
math: If you have a 100 amp alternator (at 13.8 volts), it has a source
impedance of .138 ohms, which is significantly higher than the battery,
so it's
not going to be much help. In fact, because it's going to be so heavily
loaded,
it's going to introduce some ripple into the power lines, ripple that
can be
reduced by using caps at the input of the amp.

How much capacitance is needed? There is no easy equation. There are a
number of
factors, such as the source resistance of the battery and alternator,
resistance
of the wire, ESR of the capacitors, average modulation percentage, PEP
watts,
etc, etc. Because of the very low impedance required by the amp, low ESR
is
paramount. Despite the advertised claims, the 'monster' caps usually
have an ESR
of several ohms, much higher than is usable. Computer-grade
electrolytics have a
much lower ESR. Using many smaller caps in parallel is better than one
big cap
because the ESR is much lower. Those are just a few things to consider.
But the
general rule is to keep adding caps until they no longer make any
improvement.


I'm really suprised, Tnom. After all the times you have shot your mouth
off and
been proven wrong on technical topics, you -still- haven't learned to
think
before you speak. Maybe next time.


One thing I am not surprised at........You will ignore the facts, like
you normally do to flame the group or express your pseudo
theory.

Present some FACTS, Tnom. I dare you!



Yeah...Right, A few farads will make a justifiable difference. You're
to funny.

What's funny is watching you choke on basic DC power supply theory (pun
intended).







=============

"...but I admitted I was wrong, Like a man! Something you and QRM
have a problem with. You guys are wrong and you both know it and
are both too small to admit it."
---- Twistedhed ----

=============


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

The point being, if the power supply is not capable of
supplying the current required on SSB voice peaks, then the
power supply is too small to start with. The logical 'cure'
for a 'too small' power supply is a larger power supply. Any
thing else is a 'kloodge', a crutch to prop up a cripple.
A capacitor does supply some additional current to the
system if it's large enough, but even with very large capacitors
the supplied current is going to be very, very tiny in relation
to the total current draw. Something else you should remember
is that the power supply is also going to have to charge or
re-charge that capacitor when it is drained. That means that
there is no increase in total current in the system, in fact,
there is a decrease since capacitors are not 100% efficient
(they do have loss). This means that the current demand on the
power supply has increased and the 'hole' is just getting
deeper.
Capacitors 'work' in audio systems because they 'rob' current
from one part of the audio signal and 'deposit' it in another
part of the audio signal. If the purpose is to accentuate the
high frequencies, then the 'extra' power is robbed from the
lower frequencies (or visa-versa). The total average power of
the audio signal is not changed (increased), it's only re-
ditributed.
Some things with audio system do carry over in to RF power
amplification systems, but the use of capacitors in the way you
want to use them, isn't one of them...
'Doc

PS - The "'Doc" is a nick name. It was given to me, I didn't
choose it. It does not mean that I am any kind of 'doctor',
I'm not and I've never claimed to be. When I needed a 'user'
name, 'Doc' was there, it's easy for me to remember, and so I
use it. If it has any meaning at all, it's personal and not
really very 'meaningful' to anyone else.
If you don't want to use "'Doc", then my name is Paul, use
that, or, whatever your heart desires. I don't care so long as
I know it's me you're refering to.
I hope that clears that up...
'Doc

In , 'Doc wrote:

The point being, if the power supply is not capable of
supplying the current required on SSB voice peaks, then the
power supply is too small to start with. The logical 'cure'
for a 'too small' power supply is a larger power supply. Any
thing else is a 'kloodge', a crutch to prop up a cripple.
A capacitor does supply some additional current to the
system if it's large enough, but even with very large capacitors
the supplied current is going to be very, very tiny in relation
to the total current draw. Something else you should remember
is that the power supply is also going to have to charge or
re-charge that capacitor when it is drained. That means that
there is no increase in total current in the system, in fact,
there is a decrease since capacitors are not 100% efficient
(they do have loss). This means that the current demand on the
power supply has increased and the 'hole' is just getting
deeper.
Capacitors 'work' in audio systems because they 'rob' current
from one part of the audio signal and 'deposit' it in another
part of the audio signal. If the purpose is to accentuate the
high frequencies, then the 'extra' power is robbed from the
lower frequencies (or visa-versa). The total average power of
the audio signal is not changed (increased), it's only re-
ditributed.

Exactly!

Some things with audio system do carry over in to RF power
amplification systems, but the use of capacitors in the way you
want to use them, isn't one of them...
'Doc

The power demands of an SSB amp are roughly equivalent to an audio amp simply
because of the way SSB works (low input signal, low output power; high input
signal, high output power). The current draw follows the audio almost perfectly.
Caps -do- help for SSB.






=============

"...but I admitted I was wrong, Like a man! Something you and QRM
have a problem with. You guys are wrong and you both know it and
are both too small to admit it."
---- Twistedhed ----

=============


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
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-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

The power demands of an SSB amp are roughly equivalent to an audio amp simply
because of the way SSB works (low input signal, low output power; high input
signal, high output power). The current draw follows the audio almost perfectly.
Caps -do- help for SSB.

Not even close. SSB prefers compression and HI-FI abhors it.

The difference between the two is a least 6db, therefore SSB takes
4 times the capacitance to make the same difference that a HI-FI
could show by using these caps.

The example (dx1600) requires at least 6 farads to make a difference.

In , wrote:



The power demands of an SSB amp are roughly equivalent to an audio amp simply
because of the way SSB works (low input signal, low output power; high input
signal, high output power). The current draw follows the audio almost perfectly.
Caps -do- help for SSB.

Not even close. SSB prefers compression and HI-FI abhors it.

The difference between the two is a least 6db, therefore SSB takes
4 times the capacitance to make the same difference that a HI-FI
could show by using these caps.

The DC input power follows the audio input, compressed or not. Is that concept
too difficult for you to comprehend?

The example (dx1600) requires at least 6 farads to make a difference.

Where's the math, Tnom?






=============

"...but I admitted I was wrong, Like a man! Something you and QRM
have a problem with. You guys are wrong and you both know it and
are both too small to admit it."
---- Twistedhed ----

=============


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

On Tue, 09 Dec 2003 16:07:37 -0600, 'Doc wrote:

The point being, if the power supply is not capable of
supplying the current required on SSB voice peaks, then the
power supply is too small to start with. The logical 'cure'
for a 'too small' power supply is a larger power supply. Any
thing else is a 'kloodge', a crutch to prop up a cripple.
A capacitor does supply some additional current to the
system if it's large enough, but even with very large capacitors
the supplied current is going to be very, very tiny in relation
to the total current draw. Something else you should remember
is that the power supply is also going to have to charge or
re-charge that capacitor when it is drained. That means that
there is no increase in total current in the system, in fact,
there is a decrease since capacitors are not 100% efficient
(they do have loss). This means that the current demand on the
power supply has increased and the 'hole' is just getting
deeper.
Capacitors 'work' in audio systems because they 'rob' current
from one part of the audio signal and 'deposit' it in another
part of the audio signal. If the purpose is to accentuate the
high frequencies, then the 'extra' power is robbed from the
lower frequencies (or visa-versa). The total average power of
the audio signal is not changed (increased), it's only re-
ditributed.
Some things with audio system do carry over in to RF power
amplification systems, but the use of capacitors in the way you
want to use them, isn't one of them...
'Doc

Another point is you can't equate SSB voice to music program
audio. There is the difference in compression. A direct ratio of the
capacitance needed applies to the peak to average ratio of the
power output. If your peak to average ratio in amplifier "A" is one
half of amplifier "B" then the capacitance needed for amplifier "A" is
twice as much as amplifier"B".

Music programming by default is suppose to be a true representation
of the audio. It requires a large dynamic range. The way this is done
is to not use much compression. Music programming has a very large
peak to average power ratio.


SSB voice is just the opposite. The preferred way to communicate with
SSB is to create a high order of intelligibility. This is done with
some sort of compression. Compression is desirable with a SSB voice
signal. A minimum of 6db of compression over music programming is
used.
The compression is normally quite a bit higher than 6db.

This all means that a SSB voice signal requires (6db) 4 times the
capacitance that a HI-FI audio signal requires. It is common practice
with audio amps to suggest a minimum of one farad for ever 1000 watts
of HI-FI audio, therefore a SSB voice signal would require four farads
for 1000 watts or in our case 6 farads for a 1500 watt dx1600.

1 farad cost $50, so we need $300 worth of capacitors in order to see
a difference. $300 dollars can better be spent on another battery or
two, or better yet a higher capacity alternator.

Bottom line on capacitors for SSB............Not worth the money.

I think what you stated below is what we in the Car Audio world Call "The
point of diminishing returns"
wrote in message
...
On Tue, 09 Dec 2003 16:07:37 -0600, 'Doc wrote:

The point being, if the power supply is not capable of
supplying the current required on SSB voice peaks, then the
power supply is too small to start with. The logical 'cure'
for a 'too small' power supply is a larger power supply. Any
thing else is a 'kloodge', a crutch to prop up a cripple.
A capacitor does supply some additional current to the
system if it's large enough, but even with very large capacitors
the supplied current is going to be very, very tiny in relation
to the total current draw. Something else you should remember
is that the power supply is also going to have to charge or
re-charge that capacitor when it is drained. That means that
there is no increase in total current in the system, in fact,
there is a decrease since capacitors are not 100% efficient
(they do have loss). This means that the current demand on the
power supply has increased and the 'hole' is just getting
deeper.
Capacitors 'work' in audio systems because they 'rob' current
from one part of the audio signal and 'deposit' it in another
part of the audio signal. If the purpose is to accentuate the
high frequencies, then the 'extra' power is robbed from the
lower frequencies (or visa-versa). The total average power of
the audio signal is not changed (increased), it's only re-
ditributed.
Some things with audio system do carry over in to RF power
amplification systems, but the use of capacitors in the way you
want to use them, isn't one of them...
'Doc

Another point is you can't equate SSB voice to music program
audio. There is the difference in compression. A direct ratio of the
capacitance needed applies to the peak to average ratio of the
power output. If your peak to average ratio in amplifier "A" is one
half of amplifier "B" then the capacitance needed for amplifier "A" is
twice as much as amplifier"B".

Music programming by default is suppose to be a true representation
of the audio. It requires a large dynamic range. The way this is done
is to not use much compression. Music programming has a very large
peak to average power ratio.


SSB voice is just the opposite. The preferred way to communicate with
SSB is to create a high order of intelligibility. This is done with
some sort of compression. Compression is desirable with a SSB voice
signal. A minimum of 6db of compression over music programming is
used.
The compression is normally quite a bit higher than 6db.

This all means that a SSB voice signal requires (6db) 4 times the
capacitance that a HI-FI audio signal requires. It is common practice
with audio amps to suggest a minimum of one farad for ever 1000 watts
of HI-FI audio, therefore a SSB voice signal would require four farads
for 1000 watts or in our case 6 farads for a 1500 watt dx1600.

1 farad cost $50, so we need $300 worth of capacitors in order to see
a difference. $300 dollars can better be spent on another battery or
two, or better yet a higher capacity alternator.

Bottom line on capacitors for SSB............Not worth the money.