On Mon, 11 Oct 2004 23:54:00 GMT, "Joe Rocci" wrote:

Steve,

If the inductor was not there to hold the zero-crossings of the input sine
wave at zero volts, then the whole waveform would sink toward a lower DC
voltage because it is capacitively coupled. You can prove this to yourself
by taking a large capacitor and driving a diode that is connected to ground.
The test can easily be done with audio frequencies if you don't have RF
equipment. You could also simulate it on a program like SPICE.

If the choke were removed from the circuit, this input DC shift would
reverse bias the BE junction, preventing the abiltiy of the waveform to
drive current into the BE junction. No base current = no collector current =
no gain.

BTW, I was almost sure your original post said this was a multiplier
circuit. Did the word "multiplier" not appear in it anywhere? Hmmm...


Thanks for the explanation, Joe, but no. I never said anythink about
multiplicaiton.

steve
--

Fat, sugar, salt, beer: the four essentials for a healthy diet.

Thanks for the explanation, Joe, but no. I never said anythink about
multiplicaiton

Steve,
Can you send me a copy of the original post? When these things happen, I
like to see where my crazy notions came from.

Joe
W3JDR

On Wed, 13 Oct 2004 22:58:47 GMT, "Joe Rocci" wrote:

Thanks for the explanation, Joe, but no. I never said anythink about
multiplicaiton

Steve,
Can you send me a copy of the original post? When these things happen, I
like to see where my crazy notions came from.

Here it is in its entirety....

Hi everyone,

Below you will find my attempt to show in text-form, a circuit
fragment from a 145Mhz amplifier:


--------------capacitor-------------------------------transistor base
|
|
I
|
coil
|
|
|
|
------------------------------------------------------------GND

The cap's value is 1nF; the inductor's is 0.4uH.
The cap (I assume) is to couple one amplifier stage into the next
(50ohm source/load) with minimal attenuation of the desired VHF
signal. But like what's the purpose of this inductor to ground??
--

Fat, sugar, salt, beer: the four essentials for a healthy diet.

Thanks for re-posting that Steve. I don't know where I got the crazy idea
that this was a multiplier stage....maybe I'm confusing this with a
different thread.

Thanks
Joe
W3JDR

Steve Evans wrote in message
...
On Wed, 13 Oct 2004 22:58:47 GMT, "Joe Rocci" wrote:

Thanks for the explanation, Joe, but no. I never said anythink about
multiplicaiton

Steve,
Can you send me a copy of the original post? When these things happen, I
like to see where my crazy notions came from.

Here it is in its entirety....

Hi everyone,

Below you will find my attempt to show in text-form, a circuit
fragment from a 145Mhz amplifier:


--------------capacitor-------------------------------transistor base
|
|
I
|
coil
|
|
|
|
------------------------------------------------------------GND

The cap's value is 1nF; the inductor's is 0.4uH.
The cap (I assume) is to couple one amplifier stage into the next
(50ohm source/load) with minimal attenuation of the desired VHF
signal. But like what's the purpose of this inductor to ground??
--

Fat, sugar, salt, beer: the four essentials for a healthy diet.