OTHER Splitter question

[jy2]

If I connect only two outputs of a 4 way splitter (Steren 201-244), do I get 1/2 or 1/4 strength of the original signal on each output? In other words, can a 4 way splitter serve as a 2 way splitter when only two outputs are needed?

I understand that the signal strength of each of the 4 outputs is 1/4 of that of original signal. I want to know if that holds true regardless whether an output is used.

 

[waylew]

If I connect only two outputs of a 4 way splitter (Steren 201-244), do I get 1/2 or 1/4 strength of the original signal on each output? In other words, can a 4 way splitter serve as a 2 way splitter when only two outputs are needed?

I understand that the signal strength of each of the 4 outputs is 1/4 of that of original signal. I want to know if that holds true regardless whether an output is used.

All outputs of a 4 way splitter will be the same,-7db,regardless of how many outputs are used.If you only need 2 outs use a 2 way,-3.5db.A 4 way splitter is essentially 3, 2 way splitters.

 

[cookies]

You can also use 75 Ohm terminators to block unused ports.

 

[harshness]

You can also use 75 Ohm terminators to block unused ports.

Unused ports = wasted IF signal. It is best to use the appropriate splitter.

 

[cookies]

Unused ports = wasted IF signal. It is best to use the appropriate splitter.

Just to clarify, there's no appreciable loss from using 75 Ohm terminators versus using a smaller splitter. In other words, you can have a 4-way splitter that is properly terminated on 2 outputs, and it would perform "basically" the same as a comparable 2-way splitter.
Edit: I should add that it makes no difference within reason. You only start to push the boundary when you are splitting frequencies near 2GHz by 32 ways. I can't imagine a scenario where you would be using a combination of splitters with 30 terminators and no amplification, but it's funny to think of.

 

[harshness]

Just to clarify, there's no appreciable loss from using 75 Ohm terminators versus using a smaller splitter.

To reiterate, your claim is false.

The loss is substantial and it is known from the specifications for the splitter. Using a four-way with dummy loads on all unused outputs reduces output signal on all ports by 7dB versus 3.5dB for a typical two-way splitter. In percentage terms, each output of a typical two-way splitter is approximately 44.7% of the input signal. The output of any port on a properly terminated four-way splitter is just 20% of the input signal.

Terminating resistors reduce loss due to impedance mismatch and interference from stray signal but they absolutely do not turn a four-way splitter into the equivalent of a two-way.

 

[Titanium]

Agreed, termination resistors on unused ports do not reduce signal attenuation on used ports. The loss on each port is fixed whether terminated or not.

Also, I may be stating the obvious, do not use a terminator on a power passing port. On powered ports, use a cap without termination.

 

[harshness]

On powered ports, use a cap without termination.

Good warning. That said, I note that not terminating all outputs reduces power transfer due to impedance mismatch over and above the loss of unnecessary splits. It is best to use the appropriate splitter.

 

[Brct203]

I think it should also be mentioned that using splitters on satellite systems is a bit unusual, as the communication between LNB and receiver is bi-directional (voltage-controlled polarity, 22 kHz, Diseqc) and those commands by one receiver could conflict with another receiver.

 

[harshness]

I think it should also be mentioned that using splitters on satellite systems is a bit unusual, as the communication between LNB and receiver is bi-directional (voltage-controlled polarity, 22 kHz, Diseqc) and those commands by one receiver could conflict with another receiver.

This has recently become more of a thing as the Orby TV subscription service uses only one polarity and quite a few of the Orby TV denizens here are/were using FTA antenna gear with their receivers.