(Brian Griffey) wrote
Absolutely in agreement...

Professor
www.telstar-electronics.com

hey poopfessor, how come the 10 meter amp you are selling on your web
page has no provision for CW. That part of 10m is always very active,
arent you afraid you will lose sales to 10m hams you are marketing it
to?

On 5 Oct 2004 21:13:04 -0700, (I Am Not
George) wrote in :


www.telstar-electronics.com


......oh brother. Since when did 10 meters cover 26-29MHz?

Your amp is rated 180 watts RMS and 350 watts PEP? Why is this issue
so confusing, Brian? If the amp is rated for 350 watts PEP it's rating
for AM will be 87.5 watts RMS dead-key. So where do you get your
figure of 180 watts RMS?

Your confusion seems even worse when comparing AM, FM and "PEP". If
the input can take 20 watts PEP it can take 20 watts FM. Even if your
power dissipation can't handle a steady 20 watt carrier, it should at
least be able to handle more than an unmodulated AM carrier or you
couldn't use AM. Haven't you learned the basics YET?

And what's "compression"? If you overdrive an amp you get CLIPPING,
not compression. It may be hard-clipping (typical of solid-state amps
such as your's) or soft-clipping (more characteristic of tube amps),
but it's still clipping and it still causes harmonic distortion.

On that note, let's look at those distortion figures: -33 dB with 100
watts CW..... aw, Brian, haven't you learned yet that you are supposed
to do those tests under modulation? Otherwise they don't mean squat
(and those are pretty crappy numbers for an unmodulated carrier!). If
you modulate the carrier you can test it at your rated 350 watts. But
I don't think you want to do that. In fact.....

Did you ever look closely at your input/output graph? Do you know what
the word "linear" means? And didn't you notice how the graph starts
curving more sharply at about 10 watts input? That's an indication
that your amp is clipping; i.e, causing distortion. Now we know why
you didn't measure distortion above 100 watts..... because it's a
noisy critter!!!


Brian, your amp is a cheap hack, it sucks, and you are so ignorant
that you even provided the proof. Your amps will always suck until you
finally decide to sit down and educate yourself about RF electronics
from the beginning; i.e, starting with the basics. Maybe then you can
build a decent amp and capitalize on the -legal- amp market instead of
trying to prey on hapless CBers that have been misinformed by
voodoo-techs like yourself.






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On Wed, 06 Oct 2004 01:00:07 -0700, Frank Gilliland
wrote:

On 5 Oct 2004 21:13:04 -0700, (I Am Not
George) wrote in :


www.telstar-electronics.com


.....oh brother. Since when did 10 meters cover 26-29MHz?

Your amp is rated 180 watts RMS and 350 watts PEP? Why is this issue
so confusing, Brian? If the amp is rated for 350 watts PEP it's rating
for AM will be 87.5 watts RMS dead-key. So where do you get your
figure of 180 watts RMS?

Your confusion seems even worse when comparing AM, FM and "PEP". If
the input can take 20 watts PEP it can take 20 watts FM. Even if your
power dissipation can't handle a steady 20 watt carrier, it should at
least be able to handle more than an unmodulated AM carrier or you
couldn't use AM. Haven't you learned the basics YET?

And what's "compression"? If you overdrive an amp you get CLIPPING,
not compression. It may be hard-clipping (typical of solid-state amps
such as your's) or soft-clipping (more characteristic of tube amps),
but it's still clipping and it still causes harmonic distortion.

On that note, let's look at those distortion figures: -33 dB with 100
watts CW..... aw, Brian, haven't you learned yet that you are supposed
to do those tests under modulation? Otherwise they don't mean squat
(and those are pretty crappy numbers for an unmodulated carrier!). If
you modulate the carrier you can test it at your rated 350 watts. But
I don't think you want to do that. In fact.....

Did you ever look closely at your input/output graph? Do you know what
the word "linear" means? And didn't you notice how the graph starts
curving more sharply at about 10 watts input? That's an indication
that your amp is clipping; i.e, causing distortion. Now we know why
you didn't measure distortion above 100 watts..... because it's a
noisy critter!!!


Brian, your amp is a cheap hack, it sucks, and you are so ignorant
that you even provided the proof. Your amps will always suck until you
finally decide to sit down and educate yourself about RF electronics
from the beginning; i.e, startingwiththebasics.Maybethenyoucan
build a decent amp and capitalize on the -legal- amp market instead of
trying to prey on hapless CBers that have been misinformed by
voodoo-techs like yourself.




Geeze! Why don't you tell him what you REALLY think. ;-)

Actually the term "compression" refers to the condition where a
normally linear device, starts to lose that linearity. If the gain of
your amp is 10 db, then 5 watts in should give 50 watts out. 10 watts
in should give 100 watts out. If 15 watts in only results in 120 watts
out, you are now "in compression". You call that clipping, but
compression is also a valid term for this condition. We use this term
all the time where I work. Granted the amps I work with are not as
powerful, they are still governed by the same characteristics.
Usually once "compression" is reached the incidents of second order
harmonic generation increases disproportionately with the output,
usually at a 2:1 ratio.

But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....

Dave
"Sandbagger"
http://home.ptd.net/~n3cvj

On Wed, 06 Oct 2004 07:19:53 -0400, Dave Hall
wrote in :

snip
Geeze! Why don't you tell him what you REALLY think. ;-)

Actually the term "compression" refers to the condition where a
normally linear device, starts to lose that linearity. If the gain of
your amp is 10 db, then 5 watts in should give 50 watts out. 10 watts
in should give 100 watts out. If 15 watts in only results in 120 watts
out, you are now "in compression". You call that clipping, but
compression is also a valid term for this condition. We use this term
all the time where I work. Granted the amps I work with are not as
powerful, they are still governed by the same characteristics.
Usually once "compression" is reached the incidents of second order
harmonic generation increases disproportionately with the output,
usually at a 2:1 ratio.


Let's try and clarify a few terms here.....

Clipping -- distortion that occurs on the top of a waveform due to the
signal exceeding the limitations of the circuit.

Limiting -- the result of intentionally preventing a signal from
exceeding a given level. This can be done by clipping, automatic gain
control, or both.

Compression -- a term usually applied to audio conditioning where the
amplification of a signal is varied inversely to it's input level. One
of the most common types of audio compressor is called "constant
volume amplifier".

But the problem here is that the term 'compression' has beed adopted
by voodoo techs as a euphamism for 'clipping', making it sound as if
the distortion-causing effect is not only benign, but sometimes
preferred. It is neither.


But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....


That would be nothing more than a kludge. The fault is in the design.
The response isn't even close to linear. That may be due to the bias
class, the bias regulator, the choice of active device, or just crappy
engineering overall. I suspect it's a little of everything.

YOU GUESS ARE SO SMART, WHAT THE **** YOU DOING ON CB ?

"Frank Gilliland" wrote in message
...
On Wed, 06 Oct 2004 07:19:53 -0400, Dave Hall
wrote in :

snip
Geeze! Why don't you tell him what you REALLY think. ;-)

Actually the term "compression" refers to the condition where a
normally linear device, starts to lose that linearity. If the gain of
your amp is 10 db, then 5 watts in should give 50 watts out. 10 watts
in should give 100 watts out. If 15 watts in only results in 120 watts
out, you are now "in compression". You call that clipping, but
compression is also a valid term for this condition. We use this term
all the time where I work. Granted the amps I work with are not as
powerful, they are still governed by the same characteristics.
Usually once "compression" is reached the incidents of second order
harmonic generation increases disproportionately with the output,
usually at a 2:1 ratio.


Let's try and clarify a few terms here.....

Clipping -- distortion that occurs on the top of a waveform due to the
signal exceeding the limitations of the circuit.

Limiting -- the result of intentionally preventing a signal from
exceeding a given level. This can be done by clipping, automatic gain
control, or both.

Compression -- a term usually applied to audio conditioning where the
amplification of a signal is varied inversely to it's input level. One
of the most common types of audio compressor is called "constant
volume amplifier".

But the problem here is that the term 'compression' has beed adopted
by voodoo techs as a euphamism for 'clipping', making it sound as if
the distortion-causing effect is not only benign, but sometimes
preferred. It is neither.


But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....


That would be nothing more than a kludge. The fault is in the design.
The response isn't even close to linear. That may be due to the bias
class, the bias regulator, the choice of active device, or just crappy
engineering overall. I suspect it's a little of everything.

"Marty B." wrote:
YOU GUESS ARE SO SMART, WHAT THE **** YOU DOING ON CB ?

How can you argue with that?

"Frank Gilliland" wrote in message
...
On Wed, 06 Oct 2004 07:19:53 -0400, Dave Hall
wrote in :

snip
Geeze! Why don't you tell him what you REALLY think. ;-)

Actually the term "compression" refers to the condition where a
normally linear device, starts to lose that linearity. If the gain of
your amp is 10 db, then 5 watts in should give 50 watts out. 10 watts
in should give 100 watts out. If 15 watts in only results in 120 watts
out, you are now "in compression". You call that clipping, but
compression is also a valid term for this condition. We use this term
all the time where I work. Granted the amps I work with are not as
powerful, they are still governed by the same characteristics.
Usually once "compression" is reached the incidents of second order
harmonic generation increases disproportionately with the output,
usually at a 2:1 ratio.


Let's try and clarify a few terms here.....

Clipping -- distortion that occurs on the top of a waveform due to the
signal exceeding the limitations of the circuit.

Limiting -- the result of intentionally preventing a signal from
exceeding a given level. This can be done by clipping, automatic gain
control, or both.

Compression -- a term usually applied to audio conditioning where the
amplification of a signal is varied inversely to it's input level. One
of the most common types of audio compressor is called "constant
volume amplifier".

But the problem here is that the term 'compression' has beed adopted
by voodoo techs as a euphamism for 'clipping', making it sound as if
the distortion-causing effect is not only benign, but sometimes
preferred. It is neither.


But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....


That would be nothing more than a kludge. The fault is in the design.
The response isn't even close to linear. That may be due to the bias
class, the bias regulator, the choice of active device, or just crappy
engineering overall. I suspect it's a little of everything.

On Wed, 06 Oct 2004 21:26:31 GMT, "Marty B."
wrote in :

YOU GUESS ARE SO SMART, WHAT THE **** YOU DOING ON CB ?


Sorry, I didn't know CB was reserved for illiterate morons.

On Wed, 06 Oct 2004 21:26:31 GMT, "Marty B."
wrote:

YOU GUESS ARE SO SMART, WHAT THE **** YOU DOING ON CB ?


So in other words, only dummies should use CB? I'm sure there are a
few people who would take offense to (and some who would resemble)
that comment.

Dave
"Sandbagger"
http://home.ptd.net/~n3cvj

On Wed, 06 Oct 2004 11:47:29 -0700, Frank Gilliland
wrote:

On Wed, 06 Oct 2004 07:19:53 -0400, Dave Hall
wrote in :

snip
Geeze! Why don't you tell him what you REALLY think. ;-)

Actually the term "compression" refers to the condition where a
normally linear device, starts to lose that linearity. If the gain of
your amp is 10 db, then 5 watts in should give 50 watts out. 10 watts
in should give 100 watts out. If 15 watts in only results in 120 watts
out, you are now "in compression". You call that clipping, but
compression is also a valid term for this condition. We use this term
all the time where I work. Granted the amps I work with are not as
powerful, they are still governed by the same characteristics.
Usually once "compression" is reached the incidents of second order
harmonic generation increases disproportionately with the output,
usually at a 2:1 ratio.


Let's try and clarify a few terms here.....

Clipping -- distortion that occurs on the top of a waveform due to the
signal exceeding the limitations of the circuit.

No argument.


Limiting -- the result of intentionally preventing a signal from
exceeding a given level. This can be done by clipping, automatic gain
control, or both.

Also correct.



Compression -- a term usually applied to audio conditioning where the
amplification of a signal is varied inversely to it's input level. One
of the most common types of audio compressor is called "constant
volume amplifier".

That is but one type of compression. For a more detailed discussion of
RF amplifier compression, please refer to the following related link:

http://cp.literature.agilent.com/lit...5965-7710E.pdf

Generally speaking, amplifier compression occurs when the inpututput
power ratio no longer increases db for db.


But the problem here is that the term 'compression' has been adopted
by voodoo techs as a euphamism for 'clipping', making it sound as if
the distortion-causing effect is not only benign, but sometimes
preferred. It is neither.

After reading the link, you might want to revise your definition.
There are a bunch of very talented engineers here who would be a bit
insulted to find out that you refer to them as "voodoo techs".


But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....


That would be nothing more than a kludge. The fault is in the design.
The response isn't even close to linear. That may be due to the bias
class, the bias regulator, the choice of active device, or just crappy
engineering overall. I suspect it's a little of everything.

Usually, if it is a push-pull design, device matching plays an
important part. Bias is also important, as is impedance matching. But
even a "good" design should have a follow-up low pass filter to
minimize any harmonic content.

Dave
"Sandbagger"
http://home.ptd.net/~n3cvj

On Thu, 07 Oct 2004 07:06:26 -0400, Dave Hall
wrote in :

On Wed, 06 Oct 2004 11:47:29 -0700, Frank Gilliland
wrote:

snip
Compression -- a term usually applied to audio conditioning where the
amplification of a signal is varied inversely to it's input level. One
of the most common types of audio compressor is called "constant
volume amplifier".

That is but one type of compression. For a more detailed discussion of
RF amplifier compression, please refer to the following related link:

http://cp.literature.agilent.com/lit...5965-7710E.pdf

Generally speaking, amplifier compression occurs when the inpututput
power ratio no longer increases db for db.


You should know me by now -- I just -have- to disagree. The use of the
term 'compression region' is really a misnomer. It's properly
described as a nonlinear region. The reason is that different devices
behave differently, and while a few devices (some transistors, a few
tubes, incandescent lightbulbs) have nonlinear characteristics similar
to compression, the fact is that nothing is being 'compressed', and
the vast majority of other devices have nonlinear regions that do not
resemble compression. And whether that nonlinear region is gradual or
sharp, it's still clipping because it's a limitation of the device. It
also causes distortion that is characteristic of clipping. And yes,
saturation is within the nonlinear region.

I'll give him this one. This may be a matter of semantics, like noting
the difference between 'weight' and 'mass'. I had these things drilled
into my brain by my profs for the simple reason that using the wrong
term can cause a misunderstanding. And that's what I believe is
happening when people substitute the term 'compression' for when the
transistor has exceeded the limits of linearity and subsequently
clips, be it hard or soft.

But no matter what you call it, the result is distortion.


But the problem here is that the term 'compression' has been adopted
by voodoo techs as a euphamism for 'clipping', making it sound as if
the distortion-causing effect is not only benign, but sometimes
preferred. It is neither.

After reading the link, you might want to revise your definition.
There are a bunch of very talented engineers here who would be a bit
insulted to find out that you refer to them as "voodoo techs".


I'll stick with my definition. And while I may take issue with some of
the more liberal definitions used by engineers these days, I should
point out that I worked for HP (Agilent) several years ago and I'm not
a big fan of their engineering department.


But you are right about one thing. a -33dbc harmonic rating from a
single carrier signal is pretty poor. Perhaps a chebychev lowpass
filter on the output will fix it up.....


That would be nothing more than a kludge. The fault is in the design.
The response isn't even close to linear. That may be due to the bias
class, the bias regulator, the choice of active device, or just crappy
engineering overall. I suspect it's a little of everything.

Usually, if it is a push-pull design, device matching plays an
important part. Bias is also important, as is impedance matching. But
even a "good" design should have a follow-up low pass filter to
minimize any harmonic content.


Absolutely. But even filters have limitations. Assuming Brian's amp
has 350 watt noise figures in the neighborhood of -18 to -24 dB (not
unrealistic), it would take a mighty stout filter to clean it up!