Cable Length Openbox S10 to LNB?

[hondoharry]

Using an Openbox S10 and a multiswitch what would be the maximum distance cable run?

And if you wanted more, is there a solution?

[Terryl]

This all depends on the type(s) of LNB(s) used, and the switch used.

With standard LNB(s) and Diseqc switches, a coax of about 100 to 150 feet from the STB to the switch could be used, at long lenghts RG-6 quad coax with a pure copper center conductor should be used.

With legacy +13/+18 volt switching then around 100 feet.

With Dish DPP LNB's and a DPP powered switch you can go out to 250 feet if the DPP switch is located somewhere within 50 to 100 feet of the LNB's.

Any further then that and you would need RG-11 or LDF400-75 coax.

With a single LNB looking at one satellite going to 1 receiver you could go several miles using fiber optic cable and LNB to receiver interfaces, but that gets very expensive.

[hondoharry]

Let's say with a Universal/linear LNB on 125W and a powered multiswitch, no diseqc's, you're saying the maximum distance to an Openbox S10 is around 150 ft or 100 ft? I believe this sat/LNB combo uses the 13/18 volt switching. Does it matter where in the run the multiswitch is located?

Excuse my ignorance, but I'm trying to learn. Is the maximum cable run limited by Signal or Quality? I understood signal is voltage needed for the 13/18v switching. Quality is the data from the satellite. Apart from better cable, if the limitation is caused by voltage, aren't there in line boosters that help voltage? Are there powered amplifiers for say 500 ft?

[Terryl]

Using a standard linear LNB (New type) you could get out to about 150 feet using RG-6 quad, (one solid run, no splices) the switch would not be needed on a single LNB.


"S" is not the voltage on the LNB but the signal strength of the IF signal from the LNB to the recivers input, the IF signal is what is left over once the 11250 or 10750 LNB frequency is deducted from the transponders freqency.

Example:

A TP frequency on a linear satellite at 12090 MHz is sent down to the dish, the LNB receives this and mixes the 10750 MHz LO frequency with it, a second lower IF frequency is created, this IF frequency is at 1340 MHz, it is this lower frequency that is sent down the coax to the receiver.

The RF level of this IF frequency is what the receiver uses for the "S" indication, it can be as low as 25 to 30% and still work fine on most receivers.

The "Q" is the data Quality of the decoded signal AFTER the FEC code does it's work to get rid of all incorrect data bits or fills in the missing data bits, the more FEC code that is used to correct the signal the lower the "Q" indication will be.

Some receivers will work just fine with a "Q" of around 30%, others may need more.


There may be amplifiers listed for use in satellite systems but we called them noise generators in engineering, and they have to be DC powered, so when the satellite receiver switches from one linear polarity to the other the DC voltage will go up and down, they are not much good.



So,
If you have a linear, standard or old style LNB that uses the +14 and +18 volt switching, and the run of coax is going to be over 100 feet, then an externally (no DC power inserter on the receivers coax is used, it has its own separate coax for this) DC powered legacy or standard switch could be used to run the LNB's further down the line.

EMP has switches that have an AC line input with an internal AC to DC follower power supply, these switches follow the DC switching voltage from the receiver, if a DC voltage of 12.5 to 15 volts is received from the STB then the switch uses the +13 volt input from the linear, standard or legacy LNB, if 16.5 to 19 volts is detected then the switch uses the +18 volt input from the LNB.

[Terryl]

That got quite long.

Now for the location of the switch, it should be mounted as close to the LNBs as possible, but some do not come with a weather proof container or cover, these then have to be mounted under the roof eves or in the attic/basement/crawl space out of the weather.

I would say 75 to 100 feet from the LNB on a DPP DC powered type switch, 25 to 50 feet max on a legacy or standard Diseqc switch, this depending of the quality and type of coax used.

And all switches should be grounded to prevent switching problems from stray signals.


One other contributing factor that most ignore is the 22 KHz Diseqc signals that go from the receiver to the switch/LNB's, if the coax is of poor quality in the shielding or is very cheap, this signal will degrade to a point that it can't properly control the switch, and you get switching problems.

This is why you should never skip on the cost of the coax used in a satellite system when the run of coax is going to be over 75 feet or more, it's like using a long soaker hose to fill a swimming pool, you may get some water at the other end but not much.

[hondoharry]

Let's say with a Universal/linear LNB on 125W and a powered multiswitch, no diseqc's, you're saying the maximum distance to an Openbox S10 is around 150 ft or 100 ft? I believe this sat/LNB combo uses the 14/18 volt switching, correct?. Does it matter where in the run the multiswitch is located?

[Terryl]

Why would you need the multiswitch in this setup???

A single standard linear LNB would not need it.

And yes the +14/+18 volt switching is used.

Using good quality RG-6 quad coax with the pure copper center conductor, you can go right from the receiver directly out to the LNB at around 100 to 150 feet and it should work fine.

[hondoharry]

Why would you need the multiswitch in this setup???

The multiswitch is because they want to run cable from the one LNB to 4 or more receivers, maybe 8. If all 8 receivers are 150 ft from the LNB, where is the best place to put the multiswitch? If a 2X8 multiswitch powered by 18v DC is at the end of 150 ft. from the LNB would you get another 150 ft to the 8 receivers? Think sharing an antenna with neighbors. How far away can the neighbor be?

[Terryl]

Well the maximum length from the LNB to an externally powered switch for a standard linear LNB, would be around 50 to 75 feet, then the receivers could be around 100 to 125 feet Max...

Take a look at this line of switches.


http://www.emp-centauri.cz/products.php?page=products&id_kateg=5&id_pkateg=11

And this calculator for their line of switches.

http://www.emp-centauri.cz/index_.php?page=calc&calc=1

[Terryl]

The multiswitch is because they want to run cable from the one LNB to 4 or more receivers, maybe 8. If all 8 receivers are 150 ft from the LNB, where is the best place to put the multiswitch? If a 2X8 multiswitch powered by 18v DC is at the end of 150 ft. from the LNB would you get another 150 ft to the 8 receivers? Think sharing an antenna with neighbors. How far away can the neighbor be?

If you mount the dish half way in-be-tween you two then the switch would be right at the dish, with runs to both of you of up to 150 feet.

If further then you could use RG-11 coax, you can go a bit further, somewhere up to 200 to 225 feet from the switch.

And using the calculator for thier switch and using all RG-11 coax I come up with about 80 feet from the LNB to the EMP switch, and 300 feet to the receivers, all using RG-11 coax.