Recent content by soltice_9

C should remain constant in both equations If f increases by factor of 2, X decreases by factor of 2 ... so C remains constant. Also, R is negligible in comparison to X at high frequency so it can be ignore... so C remains constant. Oh, I forgot to mention that all of the capacitance...

Oh I found something from the Manual. These are the equations that the machine use to calculate C: 1 / (2*pi*f*X) X / [2*pi*f *(R^2 + X^2)] So C decrease with frequency ... according to the machine... I'm going to go research on these 2 equations ... Thanks again Berkeman

It's ... HP 4191a impedance analyzer I'll proceed to do Cat5 cable testing tomorrow on the machine. Thank you for your help!

But my guess is that ... the machine will still tell me that C decreases with increasing frequency ... which is not correct.

I twisted the 2 Insulated Conductors together ... and hook them up to the 1st metal post ... and the foil to the 2nd metal post ... Ok, tomorrow ... I'll hook the 1st Insulated Conductor to the 1st metal post... and the 2nd Insulated Conductor to the 2nd metal post ... and don't do anything...

Hi Berkeman, It is a very old Impedance Analyzer. Although I didn't try it out, but the machine can tell me |Z|, |G|, L, and C. And it is a 1.2 meter cable. The test rig consists of 2 metal posts ... so I connected the Insulated Conductor to the 1st metal post, and the Drain (Conductor...

Thank you Berkeman. I going to take a look at my setup again. I must be doing something wrong for the machine to tell me that C varies with frequency.

Also, when someone ask for the Capacitance/meter ... does he/she have to specify the frequency too?

I have to confess that the test was done on another cable that is not Cat 5. It was just a trial test. However, it consists of Foil Twisted Pairs like the Cat 5 I bought. I got like 430 pF over 1.2 meter at 1 MHz. So, what exactly are these losses? Why do I get like 45 pF over 1.2 meter at...

I finally get to measure the capacitance between the insulated conductor and the drain (no insulation). The capacitance decreases with increasing frequency (1 Mhz increasing to 250 Mhz). I'm using an Impedance Analyzer. Is this inline with expectations? Oh, we're using STP because it's what's...

Thank you MATLABdude! I bought only 1 set of twisted-pair. It has 2 insulated conductor and 1 drain (no insulation) with a foil around the three. It appears to be 20 gauge! This thing is bigger than the average Cat-5. So I've been unsuccessful in crimping it into the RJ45 connectors I...

Hi, I'm having trouble producing 22 AWG polypropylene cable. I keep on getting "missing insulation" and "reduced insulation". The Extruder Head I'm using is quite old and I'm not sure that it is "centered". But a mechanical engineer told me not to worry, it doesn't mater if the Head is...

Hi, I'm having trouble producing 22 AWG polypropylene cable. I keep on getting "missing insulation" and "reduced insulation". The Extruder Head I'm using is quite old and I'm not sure that it is "centered". But a mechanical engineer told me not to worry, it doesn't mater if the Head is...

Hi, I've just bought 15,000 meters of Foil Twisted Pair cable (2 PVC insulated conductors and a Drain wire with Aluminum Foil around them) and I'm trying figure out if it will be good enough for Cat 5. How should I test it without having to chop it down to smaller pieces? The test...