Grounding block question

[mcap1972]

Do you loose signal strength using a grounding block?

[seahappy]

I think that would be a No ...........

[StanW]

Depending on the grounding block that you use - make sure to get the ones rated for rg6 ( if memory serves me right the plastic insert is blue) .

cp


to prevent possible signal loss issues, a ground block should be rated at 2250MHz.

[anyonomus]

Do you loose signal strength using a grounding block?



Yes you do and no you don't as seahappy mentions..

Yes u do actually loose some but not enough for it to matter unless the connections/connectors are bad/corroded or just not installed correctly or you have the wrong or inferior coax or inferior grounding block/barrel connectors
No you don't loose enough for it to change the signal unless the above is in place.
Lastly... Every time the coax is cut and connected u add a little resistance to the full length .
The coax is 52 ohms to start and every ohm added will decrease the S.
Adding connectors adds resistance.
How much??? depends on how much resistance 'U' add to the equation.
Sorry for the long winded explanation.. :)

[satchick]

Generally, you lose about 1dB per splice, with properly installed compression connectors. A 1dB drop won't even be noticeable, if you're having signal strength problems removing the ground block isn't the way to go about solving it.


The coax is 52 ohms to start and every ohm added will decrease the S.
RG6 coax has an impedance of 75ohms, and the resistance is only a couple ohms per 100ft. Impedance is like resistance for AC current; pure resistance is only used when talking about DC. The impedance of the coax doesn't change with length, and shouldn't change much with properly installed connectors.

[Terryl]

In actuality, you loose 3 dB, 1 dB per connector, and 1 dB for the ground block or "F" barrel connector.

But again 3 dB is not that much, the main concern for a satellite system coax is frequency response and center conductor type.

Legacy LNB's can work with coax that will go out to 2 GHz in frequency response, DP type LNB's need to have coax that will go out to 2.5 to 3 GHz.

The center conductor type determines the DC voltage drop at the other end, cheap coax with the copper plated center will have a higher DC voltage drop due to a higher DC resistance, the good coax with the pure copper center conductor will have less of a DC voltage drop, the types of shielding also determines the over all DC voltage drop on the system. Also the center conductors diameter will increase or decrease the DC resistance, a larger diameter center conductor will have less DC resistance.

RG-6 coax is rated at 75 ohms impedance, this is not its DC resistance, this is a calculated measurement done on the overall DC resistance, overall AC resistance, coax capacitance, coax inductance, insulator type and thickness, and distance the center conductor is from the outer shield.


So the best bet for a satellite system is, don't skimp on the coast of the coax, the better the coax the better the signal from the LNB will be.

However there are limitations, some of the standard LNB's can only be 100 to 125 feet from the receiver, DP type single satellite LNB's can go out to almost 200 feet, but you have to use good high quality coax, and it has to be rated to 3 GHz.

You may be able to go further, but you would have to use RG-11 coax, or LMR-400-75, or some heliax hard line.

We use to go several miles, but that was using fiber optic interfaces, and that was 1 LNB to 1 receiver.


Oh oh, too much coffee again, I will go away.