Frank Gilliland wrote:
Vcc
|
|
|R|
|R|
|R|
|
______|_______
| a |
_|_ _|_
\ / D1 \ / D2
_V_ _V_
| |
| |
__|__ __|__
___ ___
_ _


1. Measure voltage at point (a) with respect to ground.

2. Heat D1 with a soldering iron. Watch voltage drop.

3. Let D1 cool. Watch voltage go back up.

4. Heat D2 with a soldering iron. Watch voltage drop.

5. Let D2 cool. Watch voltage go back up.


Thus endeth electronics lesson for today.

Ok, that's just what I thought you'd draw. I claim this is useless and
won't work right. If you hook point "A" up to the base an RF device...
it'll do exactly what I described before. Either the base-emitter diode
will be on... or the other diode will be on. If the plain diode is
on... you have no current in the base of the transistor. It will be cut
off... and you have no bias at all. If the base-emitter diode is on...
you'll have some bias... but the tracking diode is off and can't do
anything. How in the world will that track anything, in either case.
Answer: It won't.

www.telstar-electronics.com

On 27 Sep 2006 15:52:43 -0700, "Telstar Electronics"
wrote in
. com:

Frank Gilliland wrote:
Vcc
|
|
|R|
|R|
|R|
|
______|_______
| a |
_|_ _|_
\ / D1 \ / D2
_V_ _V_
| |
| |
__|__ __|__
___ ___
_ _


1. Measure voltage at point (a) with respect to ground.

2. Heat D1 with a soldering iron. Watch voltage drop.

3. Let D1 cool. Watch voltage go back up.

4. Heat D2 with a soldering iron. Watch voltage drop.

5. Let D2 cool. Watch voltage go back up.


Thus endeth electronics lesson for today.

Ok, that's just what I thought you'd draw. I claim this is useless and
won't work right. If you hook point "A" up to the base an RF device...
it'll do exactly what I described before. Either the base-emitter diode
will be on... or the other diode will be on. If the plain diode is
on... you have no current in the base of the transistor. It will be cut
off... and you have no bias at all. If the base-emitter diode is on...
you'll have some bias... but the tracking diode is off and can't do
anything. How in the world will that track anything, in either case.
Answer: It won't.


Well, you just proved your foolishness by:

(1) contradicting the engineers at Motorola and other transistor
manufacturers who use diode biasing in the test circuits for nearly
every bipolar RF power transistor ever made;

(2) proving that you have never actually measured the open-base
voltage of a bipolar RF power transistor (hint: it's less than logic
would dictate);

(3) failing to understand that a bipolar transistor is a CURRENT
amplifier, not a VOLTAGE amplifier;

(4) demonstrating that your internet education didn't include the
basics of semiconductors -- specifically that the Vf/If curve has a
slope greater than zero;

(5) ignoring the fact that those "parallel" diodes which you thought
were "puzzling" were actually in series and used as temperature
sensors for a seperate bias regulator circuit; and

(6) posting your technical ignorance and inexperience in a public
forum where it can be read by any potential buyer of your amp.

So what's next from you, Brain? Some vague, Skippy-esque excuse about
how it's "part of a bigger picture"? Will you pull an Eitner and deny
the facts based on a claim of omniscience? Or will you just go back to
your same old fallacious argument that anyone who has never built a
cheap CB amp doesn't know squat?

The circuit works. If it didn't work for you then either you screwed
it up or didn't understand its function. I'm guessing both.

Frank Gilliland wrote:
Well, you just proved your foolishness by:

(1) contradicting the engineers at Motorola and other transistor
manufacturers who use diode biasing in the test circuits for nearly
every bipolar RF power transistor ever made;

(2) proving that you have never actually measured the open-base
voltage of a bipolar RF power transistor (hint: it's less than logic
would dictate);

(3) failing to understand that a bipolar transistor is a CURRENT
amplifier, not a VOLTAGE amplifier;

(4) demonstrating that your internet education didn't include the
basics of semiconductors -- specifically that the Vf/If curve has a
slope greater than zero;

(5) ignoring the fact that those "parallel" diodes which you thought
were "puzzling" were actually in series and used as temperature
sensors for a seperate bias regulator circuit; and

(6) posting your technical ignorance and inexperience in a public
forum where it can be read by any potential buyer of your amp.

So what's next from you, Brain? Some vague, Skippy-esque excuse about
how it's "part of a bigger picture"? Will you pull an Eitner and deny
the facts based on a claim of omniscience? Or will you just go back to
your same old fallacious argument that anyone who has never built a
cheap CB amp doesn't know squat?

The circuit works. If it didn't work for you then either you screwed
it up or didn't understand its function. I'm guessing both.

Well... I have no plans to argue with you on this further. However, I
am surprised that you don't understand a concept so basic as the
inherent problem of paralleling two silicon diodes together. It's
interesting the rest of the electronics world has labeled that as
taboo. There's the "electronic world"... and then there's the
"electronic world according to Frank"... LOL

www.telstar-electronics.com

On 28 Sep 2006 02:50:18 -0700, "Telstar Electronics"
wrote in
om:


Frank Gilliland wrote:
Well, you just proved your foolishness by:

(1) contradicting the engineers at Motorola and other transistor
manufacturers who use diode biasing in the test circuits for nearly
every bipolar RF power transistor ever made;

(2) proving that you have never actually measured the open-base
voltage of a bipolar RF power transistor (hint: it's less than logic
would dictate);

(3) failing to understand that a bipolar transistor is a CURRENT
amplifier, not a VOLTAGE amplifier;

(4) demonstrating that your internet education didn't include the
basics of semiconductors -- specifically that the Vf/If curve has a
slope greater than zero;

(5) ignoring the fact that those "parallel" diodes which you thought
were "puzzling" were actually in series and used as temperature
sensors for a seperate bias regulator circuit; and

(6) posting your technical ignorance and inexperience in a public
forum where it can be read by any potential buyer of your amp.

So what's next from you, Brain? Some vague, Skippy-esque excuse about
how it's "part of a bigger picture"? Will you pull an Eitner and deny
the facts based on a claim of omniscience? Or will you just go back to
your same old fallacious argument that anyone who has never built a
cheap CB amp doesn't know squat?

The circuit works. If it didn't work for you then either you screwed
it up or didn't understand its function. I'm guessing both.

Well... I have no plans to argue with you on this further.


That's because you don't understand half of what I said.


However, I
am surprised that you don't understand a concept so basic as the
inherent problem of paralleling two silicon diodes together. It's
interesting the rest of the electronics world has labeled that as
taboo.


It's not "taboo" in any book. It's only a problem if your intention is
for them to share the current equally, in which case all you need is
some form of current equalization. If they are -not- intended to share
the current equally (as in the circuit I described earlier) then it is
not a problem at all but a benefit. This happens often in electronics,
when a component, with undesireable characteristics when used in one
circuit, can be used to advantage in another. In fact, that's how the
zener diode was "invented". Did you miss that class, too?


There's the "electronic world"... and then there's the
"electronic world according to Frank"... LOL


Make all the excuses you want, Brian -- it doesn't change the fact
that you are an internet-educated hack.

Frank Gilliland wrote:
It's not "taboo" in any book. It's only a problem if your intention is
for them to share the current equally, in which case all you need is
some form of current equalization. If they are -not- intended to share
the current equally (as in the circuit I described earlier) then it is
not a problem at all but a benefit. This happens often in electronics,
when a component, with undesireable characteristics when used in one
circuit, can be used to advantage in another. In fact, that's how the
zener diode was "invented". Did you miss that class, too?

Make all the excuses you want, Brian -- it doesn't change the fact
that you are an internet-educated hack.


Easy Frank... it's only a newsgroup.

www.telstar-electronics.com

On 28 Sep 2006 08:34:36 -0700, "Telstar Electronics"
wrote in
.com:

snip
Easy Frank... it's only a newsgroup.

www.telstar-electronics.com


It's ironic how you patronize to avoid the facts while still laboring
under the delusion that your advertising gimmick is working to your
benefit. Have you ever thought about going into politics?