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https://www.satsig.net/cgi-bin/yabb/YaBB.pl VSAT technology and installation >> iDirect Forum: hubs and terminals >> SCPC in numerous Remotes https://www.satsig.net/cgi-bin/yabb/YaBB.pl?num=1224847019 Message started by smlt_vsat on Oct 24^th, 2008 at 12:16pm

Title: SCPC in numerous Remotes
Post by smlt_vsat on Oct 24^th, 2008 at 12:16pm

Hi

Some of remotes sites are showing scpc errors . it apperas and dissapears.

What may me the possible reasons

Title: Re: SCPC in numerous Remotes
Post by Dr_Sat on Oct 24^th, 2008 at 1:21pm

HI, one of the main reason is bad grounding/earthing.
check your Neutral -Ground voltages, should be Less than 3 volts. let me know if it helps.

Title: Re: SCPC in numerous Remotes
Post by TDMAMike on Oct 24^th, 2008 at 5:40pm

Downstream SCPC errors?

How many remotes are reporting errors in the entire network (example 5 of 25, etc)

How errors per remote (1245 errors, etc?) ?

Do the errors change remotes or are they persistent on the same remotes every time?

Title: Re: SCPC in numerous Remotes
Post by Eric Johnston on Oct 24^th, 2008 at 7:17pm

If you are at the hub make a list of all the sites and for each site collect the normal outlink Eb/No and BER readings.

Consider that list. �Are the sites affected by errors the ones with the lowest normal Eb/No ?. �The worst sites will be the most sensitive to local rain or to a rain fade at your hub uplink which will degrade the outlink to all sites. � �Identify the worst remote site and get it fixed. �Repeat the hit list each week or so, until you get all remote sites operating with a good rain fade margin.

If your stats show the Eb/No of a particular remote site decreasing gradually over the weeks tell them and try to resolve before failure/errors occur.

Have one remote site as a monitoring reference and closely plot its Eb/No and investigate short breaks etc which may be uplink related.

Best regards, Eric.

Title: Re: SCPC in numerous Remotes
Post by BalkanTelecom on Apr 24^th, 2009 at 11:12am

Hi,

I dont know if your problem still continues. Just a few words about scpc errors on iDirect platform:

If you see scpc errors at multiple sites in the network, then it is possibly because of downlink carrier related. Overdriven of Hub TX equipment (HPA, upnoverter i.e.) or transponder. Crosspol effect because of the other carrier(s) at the opposite pol maybe the other reason. In these cases, the modems which have lower rx snr values receive the delta scpc errors more.

Have a nice day.