On Sun, 3 Jul 2005 06:26:57 +0000 (UTC), "Reg Edwards"
wrote:

Owen,

Are you aware of programs -

Yes, of course, Reg, they and the rest of the suite are interesting...

In validating my calcualator, I have compared it to yours, Dan's
XLZIZL / TLD, Dean's TLA and Kevin's java applet. They all produce
slightly different results, one of the reasons I have tried to
document the assumptions that underly my calculator.


RJELINE2, RJELINE3, for balanced pair lines,

and COAXPAIR, COAXRATE for coaxial lines ?

These are based on exact, classical transmission line formulae and
will tell you all you could wish to know about behaviour of
transmission lines versus any complex termination from open circuit to
short circuit. No approximation of critical parameters.

However, in the coaxial case, dielectric loss is an input quantity.
;o)

Yes, I played with a model of Belden 8262, it is pasted below, and
will probably be line wrapped by a lot of news readers.

I have plugged in the dimensions from the 8262 spec sheet, and it
produces some results that are inconsistent with the specs. The
insulant diameter from the spec sheet is 4.5mm, loss/Km 13dB. (The
value for O was chosen to calibrate the DC loop resistance.) At 1GHZ,
the calculated loss was 35dB against spec of 21dB.

I played with it for a while trying to calibrate against the B8262
specs, but was unsuccessful.

Owen


N. Nominal Zo, ohms . 50.0 TERMINATION/LOAD -------------
ohms ---
D. Inner diameter, mm 0.889 R. Series Resistance
0.0
O. Outer thickness mm 0.080 X. Series Reactance
50.0
V. Velocity Factor Vf 0.6600 EQUIVALENT TERMINATION -------
ohms ---
T. Loss Factor ...... 0.000200 S. Shunt Resistance
2500000000.0
L. Line Length metres 100.000 Y. Shunt Reactance
50.0
F. Freq, kilo-Hertz . 1000.00
----------------------------- LINE CHARACTERISTICS
---------------------------
Insulant diameter 3.14 millimetres. Total Attn 10.5898
dB/kilo-m
Magnitude of Zo 51.79 ohms. Dielectric Loss 0.0275
dB/kilo-m
Angle of Zo -2.112 degrees. RF Resistance 0.1258
ohms/metre
Relative Velocity 0.6373 Inductance 0.2705
uH/metre
Electrical length 0.523 wavelengths. Capacitance 101.1476
pF/metre
DC Loop resistance 49.063 ohms/kilo-m. Conductance 0.1271
uS/metre
----------------------------- INPUT IMPEDANCE Zin
----------------------------
Series Resistance 16.51 ohms. Equivalent Shunt R 271.28
ohms
Series Reactance 64.86 ohms. Equivalent Shunt X 69.07
ohms
Magnitude of Zin 66.93 ohms. Angle of Zin 75.716
degrees
-------------------------- TRANSMISSION PERFORMANCE
--------------------------
Reflection coeff. 1.0375 Line loss when matched 1.0590
dB
Refl.coeff. angle 92.01 degrees. Actual line loss 70.8624
dB
VSWR at termination 54.296 Actual power loss in line 100.000
percent
VSWR at line input 9.696 Skin Depth 0.066 mm Q 13.5
Length = Q(1/4-wave) A(dd 1/4-wave) 3(dB) 6(0dB) =(.2%) -(.2%)
Hit N,D,O,V,T,L,F,R,X,S,Y to change data. B(egin again), E(xit
program)



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