RG6 Cable

mike-s wrote:

Gdetrailer wrote:

mike-s wrote:

Tom_M wrote:

mike-s wrote:
But if you really want to waste your money, you want hardline or LMR-600.

LMR-600 is 50 ohm and can not be used. RG-11 is quite a bit thicker than RG-6. RG-6 will work fine.

You don't know what you're talking about.

Mike-s, YOU don't know what YOU are talking about.

LMR-600 SPECS states that it IS 50 ohm (FIFTY OHM) coax.

So what? You claimed it "can not be used", which is completely and utterly false. Get a clue.

I never claimed that RG59 OR LMR-600 "can't be used", I DID SAY that IT IS NOT RECOMMENDED, GET IT RIGHT AND DON'T SNIP OUT MY TEXT TO READ THE WAY YOU WANT IT TO.

Using the WRONG AND NOT RECOMMENDED COAX WILL DEGRADE THE SIGNAL STRENGTH AND QUALITY.

So, if you want to be stupid and use the wrong coax, that IS your prerogative to do so and live with your poor choice.

Don't tell folks to make the same mistakes as you did.

You obviously have never delt with satellite IF frequencies, the LMB does a block conversion of the frequencies it sees, that block conversion results in a INTERMEDIATE FREQUENCY or IF which is sent to the sat receiver box.

Making things even more interesting is the LNBs are MULTIPLEXED on the coax, meaning there is Horizontal, Vertical for EACH LNB multiplexed on to the coax..

That means that the coax MUST handle frequencies from 1 to 2 GIGAHERTZ with as little of loss possible RG59 performs TERRIBLY at 1-2 GIGAHERTZ.



Signal loss comparison..

From HERE

Signal Loss

While shielding techniques keep external signal from affecting our signals, there is always some signal loss over the length of any cable. Here’s the breakdown of signal loss (attenuation) in decibels for 100 ft. of cable. Just remember, the longer your cable runs are, the more signal loss you will experience. That’s why it’s best to keep your installation lengths as short as possible.
RG 59 Signal Loss (in dB) per 100 ft:

Loss at 50 MHz: 2.4 dB
Loss at 100 MHz: 3.4 dB
Loss at 400 MHz: 7.0 dB
Loss at 900 MHz: 11.1 dB
Loss at 1000 MHz: 12.0 dB

RG 6 Signal Loss (in dB) per 100 ft:

Loss at 50 MHz: 1.5 dB
Loss at 100 MHz: 2.0 dB
Loss at 400 MHz: 4.3 dB
Loss at 900 MHz: 6.8 dB
Loss at 1000 MHz: 7.0 dB


At the sat IF frequencies of 1 GIGAHERTZ you could use 10 ft of RG59 for 1.2 DB loss
20ft of RG 59 2.4DB, 30ft would be 3.6DB (half of the signal).

10ft of RG6 is .7 DB, 20ft is 1.4 DB, 30ft is 2.1 DB, 40 ft is 2.8 DB, 50 ft is 3.5 DB (half signal).

I don't understand why ANYONE wants to throw out signal, your sat receiver will ALWAYS WORK BEST WITH THE MAX INPUT SIGNAL AS POSSIBLE.

Using RG59 while IS possible to do FOR SHORT distances, it IS NOT RECOMMENDED.

Using any 50 ohm coax is ALSO NOT RECOMMENDED since it WILL have considerable impedance mismatch resulting in poor performance.

IF you WANT the best possible stable operation it IS BEST to HEED the manufacturers RECOMMENDATIONS instead of deciding the you the "JR arm chair engineer" know best.. :S