Re: Okay, so, what am I missing here?

I try, as best as I can ;-) ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

The board is notched, but only to clear the end-plate on the box. The real issue is whether the footprint of the connector goes all the way to the edge of the board. For that to happen, we really have to cut copper when the fab shop routes the board. No big deal, I'll do that next time.

You

The layer 2 ground plane is deliberately cut out, under the connector, to control the impedance. There is a solid ground pour on layer 4, the bottom, between the connector tangs, but there's not much e-field down there so that doesn't matter much.

Yeah, I accumulate ideas and unknowns and, every once in a while, throw them onto a 4-layer board and have a few fabbed. Throw in a few test microstrips, filter layouts, connector adapters, whatever.

Somebody with time could accumulate layout bits from various people and do a layout, shear it up into sections, and distribute. People could share the fab expense.

--

John Larkin                  Highland Technology Inc
www.highlandtechnology.com   jlarkin at highlandtechnology dot com   

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
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Might actually be easier.

It is for someone who knows what you mean, but not for someone who knows close to nothing. After all, the very first response was confusion about "bias current." Well, if he doesn't know what it is then he can't calculate it, right? And it's not because he can't divide V by R. He didn't understand the jargon "bias current" and we might as well ask him to calculate the fubar ratio. What's a fubar?

Worse, actually, because he was at least somewhat familiar with "bias voltage" so instead of a completely alien term it seemed inconsistent with the limited knowledge he did have..

I think it may have meant something akin to "how do those (generic) things relate to my (specific) noisy speaker?"

I certainly don't want to get into an 'argument' over this but you're being rather 'selective' in the quotes. For "bias current" he tried to 'guess' you meant collector current (in the last stage) and answered

180 mA. As for gain, he figured he had enough. That, of course, isn't what you asked but what difference does it make? (I imagine him wondering since he probably didn't see that being related to his stated 'problem'). He answered the speaker and load question: "Load is an 8 Ohm speaker."

And after what you view as a mystery question he queried "What, specifically, are you thinking?"

Now, I can see that, to you, the phrase "what are you thinking?" might have sounded like a 'challenge' but I think he simply had no idea where you were going, what the purpose of the 'calculations' were (plus he didn't know what "bias current" meant), what the point was, and how it related to his, not necessarily correct, concept of the problem, which may not be the issues you were addressing.

Its not an uncommon problem when 'expert' speaks to 'novice' because what is so engrained that it's instinctively 'knee jerk' obvious to one, including the jargon, is 'huh?' to the other.

Maybe it'd be easier if I simply design it for them. No controversy, and maybe I gain a customer when they can't understand it O:-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

That showed a complete lack of common sense analytical ability. It isn't just a lack of knowledge. He was being closed-minded.

I actually remember the first time I heard of bias current. It was upon reading the datasheet for the LM319 comparator about 25 years ago. It took about 100 ms to realize that, where there is a voltage applied to a finite resistance, there is also a current, and it comes from the same source. The reason Dave didn't realize that is not because it was too hard for him. It's because he didn't know who you were, and assumed you didn't know what you were talking about, so he didn't even think about it.

He might not know how to calculate Thevinin equivalents (that the parallel resistance formula is applied to series resistors is not obvious) but he didn't ask how. He just assumed you were wrong. Yes, he said it nicely at first, but it was still an arrogant assumption.

--

Reply in group, but if emailing add one more
zero, and remove the last word.

BTW flipper this group is supposedly for working engineers. Persons like Dave should stay in s.e.b instead.

?-)

LOL. There ya go: lemonade from lemons.

Oh? That's the first I heard of it.

Probably a good place to ask questions.

But let's give the boy some credit. He did post a schematic, which is more on topic than a lot of what goes on around here.

And the person ripping on him was the worst offender.

See...

From: Jim Thompson Newsgroups: alt.binaries.schematics.electronic Subject: Re: Okay, so, what am I missing here? Date: Fri, 08 Jun 2012 09:48:31 -0700 Message-ID: ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

Lemonade (with Gain = 250X)...

Newsgroups: alt.binaries.schematics.electronic Subject: Re: Okay, so, what am I missing here? - Intercom_Possibility_KISS.png Date: Sat, 09 Jun 2012 14:48:07 -0700 Message-ID: ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

like

Slick. I'll remember that one for education of others.

?-)

No, it isn't.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)