K7ITM wrote:
Those sources also don't tell me anything about
"velocity factor" as far as I can tell.

What RF engineers call "velocity factor" is related to the phase
constant in the complex propagation constant embedded in any
transmission line equation in any decent textbook. Do your
sources tell you anything about the complex propagation constant?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

K7ITM wrote:

Those sources also don't tell me anything about
"velocity factor" as far as I can tell.


What RF engineers call "velocity factor" is related to the phase
constant in the complex propagation constant embedded in any
transmission line equation in any decent textbook. Do your
sources tell you anything about the complex propagation constant?

Complex propagation constant is ? = ? +j? :

Whe

? is the attenuation in Nepers/wavelength

? is the phase shift in Radians/wavelength

Did I pass ??????????

Dave wrote:

Complex propagation constant is ? = ? +j? :
? is the attenuation in Nepers/wavelength
? is the phase shift in Radians/wavelength
Did I pass ??????????

If I remember correctly, SQRT(Z*Y) results in a
dimensionless quantity.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

Dave wrote:

Complex propagation constant is ? = ? +j? :
? is the attenuation in Nepers/wavelength
? is the phase shift in Radians/wavelength
Did I pass ??????????


If I remember correctly, SQRT(Z*Y) results in a
dimensionless quantity.

Alpha and Beta got transformed into ? and j?. Gamma also got transformed
into ?.

What kind of bait are you throwing out about SQRT[Z*Y] ?

Dave wrote:
Alpha and Beta got transformed into ? and j?. Gamma also got transformed
into ?.

Now it makes more sense. :-) What is scarey is that some
browsers may display Greek characters correctly and some
may not.

What kind of bait are you throwing out about SQRT[Z*Y] ?

Z is the distributed series impedance and Y is the distributed
shunt admittance. The equation for the propagation constant
is gamma = alpha + j*beta = SQRT(Z*Y). Doesn't multiplying
an impedance by an admittance result in a dimensionless
quantity?
--
73, Cecil http://www.qsl.net/w5dxp

SQRT[Z*Y] = SQRT [[Z11 + jZ12]*[Y11 + jY12]] = Z11*Y11 - Z12*Y12
+jZ12*Y11 +jY12*Z11 [I think I got all the terms correct.]

So, the attenuation constant is still a complex number and it is
dimensionless.

In the transmission line equations the attenuation constant is
multiplied by line length yielding an expression in Nepers
[dimensionless] and radians [dimensionless].
Cecil Moore wrote:

Dave wrote:

Alpha and Beta got transformed into ? and j?. Gamma also got
transformed into ?.


Now it makes more sense. :-) What is scarey is that some
browsers may display Greek characters correctly and some
may not.

What kind of bait are you throwing out about SQRT[Z*Y] ?


Z is the distributed series impedance and Y is the distributed
shunt admittance. The equation for the propagation constant
is gamma = alpha + j*beta = SQRT(Z*Y). Doesn't multiplying
an impedance by an admittance result in a dimensionless
quantity?

Dave wrote:
So, the attenuation constant is still a complex number and it is
dimensionless.

The attenuation constant is a real number, not a complex number.
--
73, Cecil http://www.qsl.net/w5dxp

Presumably you meant "propagation constant" (which is anything but
constant for real lines). In any event it is most certainly is not
dimensionless. If it were and you multiplied it by a length, your
result would have units of length. Oh, and I think you left the sqrt
off the right side of the equation. I guess Z11 is resistance per unit
length, Z22 is the radian frequency times the inductance per unit
length, etc?? Sigh.

Cheers,
Tom

Opps!

ALPHA and BETA got transformed into ? and j?




Dave wrote:

Cecil Moore wrote:

K7ITM wrote:

Those sources also don't tell me anything about
"velocity factor" as far as I can tell.



What RF engineers call "velocity factor" is related to the phase
constant in the complex propagation constant embedded in any
transmission line equation in any decent textbook. Do your
sources tell you anything about the complex propagation constant?


Complex propagation constant is ? = ? +j? :

Whe

? is the attenuation in Nepers/wavelength

? is the phase shift in Radians/wavelength

Did I pass ??????????