Jim Weir: help to add car radio to aviation audio panel music input

"Carl / KG6YKL" wrote in message
newsfC9e.56373$lz2.17509@fed1read07...

snip

So, what do folks out there think?

Carl,
I thought I was bad (and often obsessed) but - GEEZ - you really need
to get a life, my friend!!!!!!! 8-)........

Good luck and best regards,

Bill

Netgeek wrote:
"Matt Whiting" wrote in message
...

RST Engineering wrote:


As to the Dr. Weir, no, I dropped out of the doctoral program when I
realized that what was being taught was roughly five to seven years

behind

the stuff that I had already done. That wasn't what I wanted to waste

my

time on ... and my own company wasn't going to pay me one cent more for

a

doctorate. I'm the "dumb" one of the family; both my brothers have

their

PhD.

Dumb isn't lacking a Ph.D., it is having your own company. :-)

Matt


Amen.... (having been there).....

On the one hand:

B.S. = Bull ****
M.S. = More ****
PHD = Piled Higher and Deeper

But the truth is:

(Sung to the tune of the Mickey Mouse theme song)

M..I..T
P..H..D..
M..O..N..E..Y..!!!


Yes, but the sad part is that an MBA will get you even more money for
less upfront time investment.


Matt

As far as the circuit goes, I looked on the web for some help and came
across a site that appears to show the circuit you are talking about.
The site is:
http://hyperphysics.phy-astr.gsu.edu.../npncc.html#c3

and shows a diagram of the circuit. Is this the right one? If so, I
still need help (I'm not in the league one of the freshmen students you
refer to - sorry!) in determining the actual value of the resistors and
capacitors and transistor parts needed. I can make my way to Radio
Shack or Frys Electronics to buy the stuff and assemble it, but I just
don't have the background to determine the values. Thanks for your
help!
Brian


Click on the "to numeric examples" and it gives values and how to
determine them.


Yes, for someone who knows what it's talking about - I don't even know
where to begin. It appears they come up with numbers from who knows
where and I don't think they start with the impedance and go from there.
That's my problem - I don't want to spend another day staring at those
equations only to get frustrated if someone could just tell me where to
begin!

Brian

doubleplusungood!


Isn't that making fun of overweight people?

Not a problem. If you are trying to make the transistor impedance
converter, and you have a Rat Shack 2N2222 or PN2222 or some other garden
variety NPN transistor ... then ...

Look at the "front" of the transistor. That's the "flat" side. Hold the
transistor with the flat side towards you and the wire leads down.

From the left to right, the leads are "emitter", "base", and "collector".
Don't worry about what the words mean right now.

You also have several inputs to this little amplifier. One is the +12
battery voltage. One is airframe ground. One is the Alpine audio output.
(The Alpine needs a common ground to airframe.)

The collector of the transistor goes directly to +12 battery supply (through
a LITTLE TINY fuse).

The emitter goes to ground through a 470 ohm resistor.

There is a 47K resistor going from the collector to base. There is a 47K
resistor going from base to ground.

There is a 100 nF capacitor (0.1 uF) from the Alpine audio output to the
base of the transistor.

There is a 10 uF capacitor from the emitter of the transistor to the input
of the audio panel. This will undoubtedly be an electrolytic, so the (+)
lead of the capacitor is to the emitter of the transistor and the (-) lead
is to the audio panel.

Did that help?


Jim






Yes, for someone who knows what it's talking about - I don't even know
where to begin. It appears they come up with numbers from who knows where
and I don't think they start with the impedance and go from there. That's
my problem - I don't want to spend another day staring at those equations
only to get frustrated if someone could just tell me where to begin!

Brian

RST Engineering wrote:
Not a problem. If you are trying to make the transistor impedance
converter, and you have a Rat Shack 2N2222 or PN2222 or some other garden
variety NPN transistor ... then ...

Look at the "front" of the transistor. That's the "flat" side. Hold the
transistor with the flat side towards you and the wire leads down.

From the left to right, the leads are "emitter", "base", and "collector".
Don't worry about what the words mean right now.

You also have several inputs to this little amplifier. One is the +12
battery voltage. One is airframe ground. One is the Alpine audio output.
(The Alpine needs a common ground to airframe.)

The collector of the transistor goes directly to +12 battery supply (through
a LITTLE TINY fuse).

The emitter goes to ground through a 470 ohm resistor.

There is a 47K resistor going from the collector to base. There is a 47K
resistor going from base to ground.

There is a 100 nF capacitor (0.1 uF) from the Alpine audio output to the
base of the transistor.

There is a 10 uF capacitor from the emitter of the transistor to the input
of the audio panel. This will undoubtedly be an electrolytic, so the (+)
lead of the capacitor is to the emitter of the transistor and the (-) lead
is to the audio panel.

Did that help?

Thanks you very much!!! That is a BIG help. Thank you for taking the
time to do this. I'll let you know how it turns out!

Regards,
Brian

RST Engineering wrote:
Not a problem. If you are trying to make the transistor impedance
converter, and you have a Rat Shack 2N2222 or PN2222 or some other garden
variety NPN transistor ... then ...

Look at the "front" of the transistor. That's the "flat" side. Hold the
transistor with the flat side towards you and the wire leads down.

From the left to right, the leads are "emitter", "base", and "collector".
Don't worry about what the words mean right now.

You also have several inputs to this little amplifier. One is the +12
battery voltage. One is airframe ground. One is the Alpine audio output.
(The Alpine needs a common ground to airframe.)

The collector of the transistor goes directly to +12 battery supply (through
a LITTLE TINY fuse).

The emitter goes to ground through a 470 ohm resistor.

There is a 47K resistor going from the collector to base. There is a 47K
resistor going from base to ground.

There is a 100 nF capacitor (0.1 uF) from the Alpine audio output to the
base of the transistor.

There is a 10 uF capacitor from the emitter of the transistor to the input
of the audio panel. This will undoubtedly be an electrolytic, so the (+)
lead of the capacitor is to the emitter of the transistor and the (-) lead
is to the audio panel.

Jim,

So what did you assume for the Alpine's voltage in coming up with these
numbers; 4V rms or p-p? Speaking to a friend of mine today, he's
positive it is rms.

Brian

"Carl / KG6YKL" wrote in message
newsfC9e.56373$lz2.17509@fed1read07...
RST Engineering wrote:

jury-rig solution

jury-rig is correct and is a nautical term meaning to make a temporary
repair using available materials to solve a problem.


Okay, this is way off topic but I have to know the history of this
expression. It is my understanding that the correct term is
"Jerry-rigged" or "Jerryrigged" which is based on the pejorative term
"Jerry" for Japanese, used during WWII. The way it was told to me is that
near the end of WWII Jerry (the Japanese) were badly beaten and much of
their equipment was non-operational. However the Japanese were very
resourceful at doing whatever it took to get things working. So people
started talking about "Jerry-rigging" things.


In WWII the Germans were "jerrys" while the Japanese were "nips."



Obviously the term "Jerry" is racially insensitive which probably led to
the alteration of the term. However, isn't "Jerryrigged" a complimentary
term when you consider it implies resourcefulness? Lemmonaide from
lemmons?

So, when I read Jim's post I did a quick Google search and found a
different explanation:

Most sources claim that the origin of the word jerryrig is unknown, but
William and Mary Morris, in Dictionary of Word and Phrase Origins (see my
bibliography), indicate that the term is likely a corrupted form of
juryrig, which referred to temporary rigging on a ship. Jury as used in
juryrig (which arose in the 17th century) likely comes from Old French
ajurie `help, relief.' The 'temporarily repair' sense remained with the
word juryrig, while its nautical roots faded away. The vulgar expression
to which you refer is likely patterned after juryrig and jerryrig.

To say that something is "jerryrigged" is to mix idioms a bit, because
the proper term is "jerrybuilt." A "jerrybuilder," a term dating to
19th-century England, was originally a house builder who constructed
flimsy homes from inferior materials. The "jerry" in the term may have
been a real person known for the practice, or may be a mangled form of
"jury," as in "jury-rigged." I tend to think that "jerrybuilt" arose
separately from "jury-rig" simply because their senses are slightly
different. Something that is "jury-rigged" is concocted on the spur of the
moment to meet an emergency, but something "jerrybuilt" is deliberately
constructed of inferior materials to turn a quick buck.


So, what do folks out there think?

Carl.

PS- Isn't it strange what catches your interest sometimes?

Highflyer wrote:
"Carl / KG6YKL" wrote in message
newsfC9e.56373$lz2.17509@fed1read07...

RST Engineering wrote:


jury-rig solution


jury-rig is correct and is a nautical term meaning to make a temporary
repair using available materials to solve a problem.


Okay, this is way off topic but I have to know the history of this
expression. It is my understanding that the correct term is
"Jerry-rigged" or "Jerryrigged" which is based on the pejorative term
"Jerry" for Japanese, used during WWII. The way it was told to me is that
near the end of WWII Jerry (the Japanese) were badly beaten and much of
their equipment was non-operational. However the Japanese were very
resourceful at doing whatever it took to get things working. So people
started talking about "Jerry-rigging" things.


I guess consulting a dictionary was out of the question? Anyhow, it
goes back to way before WWII. It's old nautical slang.

The term from the American Heritage Dictionary of the English Language says:
From jury-rig, jury-rigging, improved rigging on a ship, modeled on
jury-mast, temporary mast, perhaps untimely from Old French ajure, help,
from aider, to help.

The OED finds reference to jury mast as far back as the year 1616. The
first use of Jury rig is in 1788. The OED doesn't give credance to the
French derivation however, it also notes the unsupported suggestion that
it is a corruption of "injury".

There's a post in rec.aviation.ifr titled "Garmin GMA 340 Music Input"
that I found by accident while trying to find the melee I got caught up
in. In it someone is describing using transformers (from "RatShack" no
less) to impedance match a line level output to his Garmin 340 input.
Apparently it worked out for that guy. So if you haven't selected and
biased your transistors yet, check it out.