Proper Electrical resistance of cable 2 way splitter. Made by Antronix P/N CMC2002H.?

Question

I was having many functional issues with my Comcast high speed internet connection. I removed the splitter(Freq. range 5-1000Mhz. -3.5db)
that feeds one DVD/VCR and the desk top. Connection now direct too wall outlet. Now my connection is great. Question is whats the proper elec. resistance of splitter in question. I measured infinte/open resistance with a fluke 189 through the splitter, if that true how did connection work at all period. Or is DVD/VCR effecting the cable line? I'm I measuring splitter properly?

Answer 1

That splitter is what the radio frequency (RF) people call a band-pass device. A good one should be open at DC (as measured by an ohm meter), and only couple (conduct) when the RF signal of a frequency within its designed pass band is applied.

To test such splitter, RF people don’t measure its resistance. They measure its “insertion loss” which is the RF power coming out at either of its two output ports when a known RF power of frequencies within its pass band is applied at the input port. An ideal two-way splitter should have what they call a “3 dB insertion loss” (50% power, not voltage, reduction) between the input and any one of the two outputs because the input power is divided into two output branches. You need what RF folks call a Network Analyzer to do the insertion loss test.

By the way, in an RF design labs, in addition to how close to 3 dB the splitter’s insertion loss is, other performance metrics to tell which splitter is better may include: (1) gain flatness: for all frequencies in the pass band the insertion loss should be the same; (2) constant group delay: to provide no phase jitters to an RF signal that carries digital info in its phase and not in its amplitude or frequencies--group delay is defined as the negative of the first derivative of the phase vs. frequency; (3) input return loss: the fraction of the input power that bounces back at the input port; (4) output return loss or directivity: the ability to gracefully absorb any RF that travels on the reverse direction into one of the two output ports so that if you open the other end of a cable that connects to the first output port no flickering would appear on, say, your TV connected to the second output port; and (5) characteristic impedance flatness: the 75 ohm that you may see on the labels is the resistor value that if used to connect the end of the cable to ground no RF signal will reflect backwards--this value should be flat for all frequencies in the pass band looking into any one of the three ports.

Answer 2

Two very good technical answers that are indeed correct. Now how about a simple one? Get what is called a "T" connector. It is a simple device that has a center conductor, and the outside shell. Connect the cable from the wall to one connector port of the "T", and connect the other 2 ports, one to the computer, and one to the DVD/VCR. There is no, or extremely little insertion loss using such a device. If you want a "splitter" then you need one that is going to give the same signal level at the output ports as what is delivered to it. This would be an active, or powered splitter.

Answer 3

A splitter is not a purelyy resistive device. It is either an active or passive type device which is made up of components to split the signal from the source at X power level to two (or more) secondary signals at equal power levels. usually these devices reqiure a given priamary (source) impedance and a given secondary impedance to work correctly. If there is an imbalance the devcie may not produce an acceptable signal level to the secondary device. Or it is just plain broken. Get another one. But using a ohm meter will not tell you a whole lot about the device working or not. You would need a known signal source and a spectrum anaylzer to know if it was actually working or not.

Answer 4

All you % is a Ethernet change. you are able to connect the change to the Cable Modem, and then connect as many ethernet contraptions (computers, laptops, ethernet printers etc) to the change, based upon how many outgoing ethernet ports your change has. in case you think of you won't be able to locate the money for a router/change, think of back, are you able to locate the money for to not have one? could be definite, in case you do not % to connect the two computers. yet differently out, is you are able to connect the own workstation to the cable modem immediately and the workstation wirelessly, if the cable modem enables you to try this.