I have a satellite dish in the yard and a coax cable from there to my modem.

I can view the current state of the modem and signal in real time.
One indicator on that screen is CABLE ATTENUATION.

The way I understand, or misunderstand............is the lower the number on CA, the better or more efficiently it is operating.
Please correct me if I'm wrong.

For many months that CA reading was 14.1 and rarely fluctuated.

A few days ago it dropped to 4.8

My question is .what would cause that drop ?

Have you inspected the cable for damage?

Perhaps a new satellite is providing a better signal or the controllers here on earth were able to remotely improve the satellite performance.

Chris

Could be the frequency has been tuned or there is damage to the cable, a corroded cable will quickly degrade and change it but still service some what

Service could have been upgraded without your notice, even a solar flare can change this reading

I haven't looked for damage. The cable is only visible for about two feet from the LNB. At that point it enters a waterproof tube and runs underground until it comes up through my floor ...into a wall and then to the modem. Not really anywhere it could get damaged.

But, isn't it a GOOD thing that the CA dropped ??

I was wondering that same thing Chris but I don't know whether something like that is possible. I thought it was a reflection of cable condition

Right now it is reading 4.8 dB. Is that a measurement of noise in the cable ??

A search found this, I hope it helps you more than it did me. Still looking.
TX freq 29.5 - 30 GHz
RX freq 19.7 - 20.2 GHz

Coax cable frequencies:
RX 300-800 MHz. model TR4000N-10
RX 1000 - 1500 MHz. model RM4200N-10
TX 1800 - 2300 MHz.�

Regarding the cable:
DC resistance maximum value = 2.27 Ohms
Attenuation maximum values 9.17 dB at 1000 MHz and 14.3 dB at 2200 MHz

Using good copper core cables, properly terminated, maximum lengths.
30 m using RG59 Cable
50 m using RG 6 Cable
100 m using RG 11 Cable.

If you want to view the spectrum in the cable with a high loss coupler make sure not to short circuit the cable or allow 30V DC to the spectrum analyser.

Any measured spectrums please tell me your location and sent to eric@satsig.net

There are four beam colours and I think these refer to four different frequency usages, to minimise interference between beams:
For example:
19.7-19.95� RHCP� �29.5-29.75� LHCP
19.95-20.2� RHCP� �29.75-30� � LHCP
19.7-19.95� LHCP� �29.5-29.75� RHCP
19.95-20.2� LHCP� �29.75-30� � RHCP�

This arrangement provides 250 MHz bandwidth per beam.
Considering the receive spectrum you will probably see several steady carriers, each 27 MHz wide with bit rate 67 Mbit/s in clear sky.� �Towards beam edge locations, you should see lower level carriers in the adjacent beams.
On transmit, you may see fast transient, narrower bandwidth, bursts, whenever your site transmits.

Your receive C/N depends on the signal in the air as it arrives at your dish plus the G/T of your terminal. The G/T depends on dish gain and receive noise temperature of the LNB. 75cm dish has G/T=+17 dB/K. The C/N is hardly affected by cable length, until you go beyond the extreme maximum lengths. If you have too high DC resistance, ant thus low supply volts/amps at the dish, the transmit and receive qualities will both deteriorate.

Each additional connection adds about 5db. So the 2 connections at the modem + the length of the cable your normal reading of 14.1 sounds right. For it to change to 4.8 hmmm, did the indicator loose the tenths spot? Some kind of soft wear change maybe. Or a miraculous improvement of connections.
As long as your reception is normal just an interesting anomaly to make note of.
Hope this helps....

MJM: This is a giant weak spot in my education. It may as well be Greek. But I do know I am using RG 11 cable and the run from the dish to the modem is about 80 feet.


Bob: It certainly could be a software upgrade as that usually happens at night without my knowledge. The change was sudden and that is what got my attention. I started experiencing more frequent signal outages and that made me look at the statistics to see if anything was changing. Sure enough, things had gotten better LOL !!

white17 You mean that wasn't Greek? It sure looked like it to me.

LOL ! Very well could be !!

Ken are you using explorenet? I remember ours had that same indicator screen. What is your signal strength?

Here is an explanation of it. Cabel attenuation

No Dave, I'm using Viasat . It stinks generally ! My signal strength at the moment is 7.0 out of 10 possible.


Thank you Pete. I wish I had a better understanding of that stuff

Don't count out mice as a possibility. Water in a connector can raise cane as well.

I have thought about both of those too. Water could only get in right where it connects to the LNB at the dish.

I don't think a rodent could access the cable anywhere

Ole Blister is tired of you watching those videos!!!