Amp Design Concept -- Preliminary
 

"Telstar Electronics" wrote in message
s.com...
I have to agree that 50 ohm striplines are useless in an amp like this,
it
is only important that the output impedance of the driver stages match
the
driven stage.

Matching is always important for maximum power transfer. Why do you
think it's any less important in an amp such as this???


Well, this one sucks. It's advertised ratings are fictional.

Amp Design Concept -- Preliminary
 

U-Know-Who wrote:
Well, this one sucks. It's advertised ratings are fictional.

You know who is the only fictional thing here...

www.telstar-electronics.com

Amp Design Concept -- Preliminary
 

On a sunny day (25 Sep 2006 16:32:49 -0700) it happened "Telstar Electronics"
wrote in
m:

I have to agree that 50 ohm striplines are useless in an amp like this, it
is only important that the output impedance of the driver stages match the
driven stage.

Matching is always important for maximum power transfer. Why do you
think it's any less important in an amp such as this???


OK, I will now explain, as this is the second time you ask, and you
fail to see some basic concepts.

OK, lets assume you _have_ a perfect 50 Ohm PCB track.

No lets also assume you _have_ a perfect 50 Ohm source impedance to drive it.

What would we need to f*ck this up 100% by means of the 'impedance mismatch'
you are so worried about?

Simple, here is an example:

A
50 Ohm Generator ------------------------------------ B
||
|| end open (not terminated) PCB track of 50 Ohm impedance.
T ||
||__ GND


So _HOW_LONG_ should track T need to be to form a short for say 10 meters wavelength?
If it was to be a short, the reflected wave from the non terminated (open) end would
have to arrive in the exact opposite amplitude back in A, to 'nullify' the signal in
conductor B, resulting in 0V signal in B.


. .

Amp Design Concept -- Preliminary
 

Jan Panteltje wrote:
So you asked before 'when does this issue become important?'.
It becomes important when the designer thinks a significant enough effect is present.
This will normally be when we work with wavelengths that are closer to the PCB track length,
As you want no harmonics ;-) this should not be a big issue in the case of your amp.

I agree that this effect becomes more pronounced at higher
frequencies... but it's always good practice to incorporate it if
possible.

www.telstar-electronics.com

Amp Design Concept -- Preliminary
 

On a sunny day (26 Sep 2006 04:38:57 -0700) it happened "Telstar Electronics"
wrote in
.com:

Jan Panteltje wrote:
So you asked before 'when does this issue become important?'.
It becomes important when the designer thinks a significant enough effect is present.
This will normally be when we work with wavelengths that are closer to the PCB track length,
As you want no harmonics ;-) this should not be a big issue in the case of your amp.

I agree that this effect becomes more pronounced at higher
frequencies... but it's always good practice to incorporate it if
possible.

www.telstar-electronics.com

I sincerely hope you did read, or are going to read, that tutorial.
http://www.tpub.com/content/neets/14...s/14183_51.htm
Also I expected some remark, but anyways;
Look ma, no math:
http://www.allaboutcircuits.com/vol_2/chpt_13/6.html

It is interesting stuff, once you start designing for GHz range, or
fast digital logic, a must.
But it will help you with the CB antennas and cables too.

I would not lose sleep over you PCB track impedances in that amp,
just make sure the Pi filter matches that amp to 50 Ohms, else any
reflections will be from the coax back to the amp, not from any PCB traces.

Amp Design Concept -- Preliminary
 

Jan Panteltje wrote:
I would not lose sleep over you PCB track impedances in that amp,

Never intended to... it's just good design practice.

www.telstar-electronics.com

Amp Design Concept -- Preliminary
 

On a sunny day (26 Sep 2006 04:54:13 -0700) it happened "Telstar Electronics"
wrote in
. com:

Jan Panteltje wrote:
I would not lose sleep over you PCB track impedances in that amp,

Never intended to... it's just good design practice.

No it is madness.
quote
A genius is somebody who knows what NOT to pay attention to.
end quote

Amp Design Concept -- Preliminary
 

Jan Panteltje wrote:
A genius is somebody who knows what NOT to pay attention to.

Then maybe I'll just start ignoring you... LOL

www.telstar-electronics.com

Amp Design Concept -- Preliminary
 

On a sunny day (26 Sep 2006 06:06:20 -0700) it happened "Telstar Electronics"
wrote in
. com:

Jan Panteltje wrote:
A genius is somebody who knows what NOT to pay attention to.

Then maybe I'll just start ignoring you... LOL

www.telstar-electronics.com


Yo ureall yare of you rocker now are you?
VERY extensive help and explanations I have given you.
You do not learn.
You have no electronics eduction obviously.
Yo udo not WANT to learn.

And you are wrong many times, if not nearly always,
And then yo ustart insulting those who want to teach you?
Go to hell idiot.
And take your crap spam about that amp with you.

Amp Design Concept -- Preliminary
 

Jan Panteltje wrote:
Yo ureall yare of you rocker now are you?
VERY extensive help and explanations I have given you.
You do not learn.
You have no electronics eduction obviously.
Yo udo not WANT to learn.

And you are wrong many times, if not nearly always,
And then yo ustart insulting those who want to teach you?
Go to hell idiot.
And take your crap spam about that amp with you.


I say again... if you are so smart... then where is your amplifier?
Produce your design and photos to substantiate. Oh, you can't... just
as I thought. It seems we have numerous back-seat drivers on this NG
that profess great knowledge in amplifier design. I say welcome all amp
gods... but produce your design. If you can't, then you have no
business claiming to be a deity.

www.telstar-electronics.com