Weak satellite signal

Forums › Freeview (DVB-T/DVB-S) › Weak satellite signal

amphibem

138 posts

Master Geek

#31405 16-Mar-2009 22:07

So after my earlier post here I have managed to run satellite into my room using a total run of about 30m with 3 inline connectors (2 of which are splitters with nothing else on them). I have managed to find channels in MediaPortal after a bit of fiddling around but I can only get TVNZ channels, and although they scan in the play like a slideshow. So I am thinking the signal is too weak, due to the cable run and/or the number of connectors.

So what I want to know, what is the easiest and cheapest way to fix this; amplify or shorten the cable run. Noting that shortning the cable run involves crawling under the house and cuting into the satellite cable and splitting closer to the dish, which could probably cut the cable length by about 10m. The earliest point I could put amplification in (assuming closer to dish is better, and it needs a power source, and such an amplifier exists) would be about 10m from the dish.

So to sum up, I know there is a signal getting from space to my computer but it is too weak. Will reducing the cable run to 20m and cutting back to one inline connector likely fix my problem, or is there a better way such as amplification.

Cheers

Desktop: 5200 X2 - 3GB - 320GB - Nvidia 8600GT - Vista Home Premium - PVR150 - MediaPortal 1.0
My HTPC Blog - HTPCnz, the Home Theatre PC Resource

Jaxson

8172 posts

Uber Geek
+1 received by user: 1332

Trusted

#201557 17-Mar-2009 09:14

First I'd look at removing the splitters along the way temporarily to see if that improves things. Use a threaded rod type connector (assuming you've used f connectors) like http://www.freeviewshop.co.nz/type-inline-adaptor-femalefemale-p-107.html

Getting some channels but not all on sat often means the skew of your lnb is not perfect. A simple sat meter is not enough to tune this, you have to go by the quality value on the htpc or stb. One one of the mux's there is a signal on both the H and V alignments, so the signal meter will always show a signal, even though you only want one of the two available.

If you want to know if moving closer will help things, how about move your htpc or stb to one of the closer points where you put a splitter. All basic things you can try before spending money.

amphibem

138 posts

Master Geek

#201597 17-Mar-2009 12:35

Jaxson: First I'd look at removing the splitters along the way temporarily to see if that improves things. Use a threaded rod type connector (assuming you've used f connectors) like http://www.freeviewshop.co.nz/type-inline-adaptor-femalefemale-p-107.html

Getting some channels but not all on sat often means the skew of your lnb is not perfect. A simple sat meter is not enough to tune this, you have to go by the quality value on the htpc or stb. One one of the mux's there is a signal on both the H and V alignments, so the signal meter will always show a signal, even though you only want one of the two available.

If you want to know if moving closer will help things, how about move your htpc or stb to one of the closer points where you put a splitter. All basic things you can try before spending money.

Thanks for that. Going to move the tuner closer (eliminate 7m of cable) tonight see what happens, then look at replacing splitters with inline connectors. See how it goes from there.

Desktop: 5200 X2 - 3GB - 320GB - Nvidia 8600GT - Vista Home Premium - PVR150 - MediaPortal 1.0
My HTPC Blog - HTPCnz, the Home Theatre PC Resource

richms

29097 posts

Uber Geek
+1 received by user: 10206

Trusted

Lifetime subscriber

#201638 17-Mar-2009 15:17

splitters with nothing on the other leg are a huge problem, they either need to be really close to the LNB or distribution amp, or really close to the recievers so that the standing waves they get in the cable are less likly to corrupt the data coming thru. One in the middle will make all sorts of crap happen as the signals bounce back and forth along the cable.

$2 shops have the thru connectors normally, not great quality but a hell of a lot better then the mismatch of an unloaded splitter port.

Richard rich.ms

Jaxson

8172 posts

Uber Geek
+1 received by user: 1332

Trusted

#201648 17-Mar-2009 15:54

Good point, that's what the end plugs were for isn't it?
Might pay to cap them off if need be, assuming the splitter really needs to be there in the first place.
http://www.freeviewshop.co.nz/type-terminator-plug-p-106.html

Also the skew is really worth a look if you're getting just one mux ok.

amphibem

138 posts

Master Geek

#201671 17-Mar-2009 17:17

OK so I just tried with the last 7m cable (and splitter attaching it) removed and got the same result, so I don't think line length is the problem. So as I understand that leaves two possibilites:

1. Skewed dish. How do I go about testing this from my computer (or can I?). From:

Jaxson:A simple sat meter is not enough to tune this, you have to go by the quality value on the htpc or stb.

When you quality value you mean signal strength? What is the easist way to get this reading with MP or other software?

2. Interfence from splitter. The splitter is there so that the occupants in the main house have the satellite avaliable should they want to get Freeview themselves. So I could replace the splitter (which is under the house) with an inline connector but would then have to crawl back under if they wanted to use their satellite. It would be good to avoid this possible, so if I cap the end of the cable running of the other end of the splitter (the end which terminates in their house) will that have the desired effect?

I will try and find some inline connectors and terminators in town tommorow (I live in Hawera, not a lot of places which sell such things) and try to fix issue 2 tommorrow night.

Greatly appreciate your guys help, keep it coming!

Desktop: 5200 X2 - 3GB - 320GB - Nvidia 8600GT - Vista Home Premium - PVR150 - MediaPortal 1.0
My HTPC Blog - HTPCnz, the Home Theatre PC Resource

richms

29097 posts

Uber Geek
+1 received by user: 10206

Trusted

Lifetime subscriber

#201678 17-Mar-2009 17:40

Oh dear, an unused cable off a splitter port is even worse if that splitter is not right at the source, definatly put a 75 ohm terminator on the end of it. You will see a drop in signal levels but the quality will be higher since some of what you are seeing is the reflection off the unterminated cable end.

IMO its best to whach an amplifier at any splitter when you think you will be seeing cables unterminated off it since the amp is now the souce of the signal, it will lower the amount of crap bouncing around in the cables.

Richard rich.ms

Geekzone

Want to support Geekzone and browse the site without the ads? Subscribe to Geekzone now (monthly, annual and lifetime options).

mjb

996 posts

Ultimate Geek
+1 received by user: 67

Trusted

#201681 17-Mar-2009 17:46

How old is the LNB on the dish?

contentsofsignaturemaysettleduringshipping

amphibem

138 posts

Master Geek

#201693 17-Mar-2009 18:08

mjb: How old is the LNB on the dish?

It can't be very old because it uses 10750MHz as the LOF. Although it doesn't look like either of the Sky ones shown here it would appear to be a variation on the new one, 2 LNB's with one cover over the whole thing (it looks like an eleipse, not a circle).

I also know it was used as recently as November last year which I wouldn't think was long enough for major water damage to occour.

Desktop: 5200 X2 - 3GB - 320GB - Nvidia 8600GT - Vista Home Premium - PVR150 - MediaPortal 1.0
My HTPC Blog - HTPCnz, the Home Theatre PC Resource

mjb

996 posts

Ultimate Geek
+1 received by user: 67

Trusted

#201776 17-Mar-2009 22:35

Sweet as, you can most likely rule that out then. Yeah, next option is to try realigning the dish using signal strength on a receiver.

The other thing you can do is rule out your cable entirely by using a shorter fly lead from the LNB to your receiver. I appreciate that this may not be physically possible, but worth it if you can do it.

contentsofsignaturemaysettleduringshipping

amphibem

138 posts

Master Geek

#201823 18-Mar-2009 07:01

mjb:The other thing you can do is rule out your cable entirely by using a shorter fly lead from the LNB to your receiver. I appreciate that this may not be physically possible, but worth it if you can do it.

Depending on how the cable is attached to the dish I could do that because the dish is attached to side of the house just out my backdoor. I will keep that in mind as my last option!

Desktop: 5200 X2 - 3GB - 320GB - Nvidia 8600GT - Vista Home Premium - PVR150 - MediaPortal 1.0
My HTPC Blog - HTPCnz, the Home Theatre PC Resource

cyril7

9073 posts

Uber Geek
+1 received by user: 2499

ID Verified

Trusted

Subscriber

#201828 18-Mar-2009 07:23

Sounds to me like its either the dish is out of alignment, which if no one has touched it since the LNB was upgraded is unlikely, they rearly move unless youve have a very large storm, or you have a bad connector termination, what connectors did you use, how well did you do the job.

A 30m run with 2 or 3 splitters is 15-20dB of loss which is well inside the budget for line losses, if you have no terminations on some ports then the splitter losses will be slightly less than advertised, however if you dont need them then use female F barrels.

Cyril

AliExpress

Shop now on AliExpress (affiliate link).

mjb

996 posts

Ultimate Geek
+1 received by user: 67

Trusted

#201844 18-Mar-2009 08:51

amphibem: Depending on how the cable is attached to the dish I could do that because the dish is attached to side of the house just out my backdoor. I will keep that in mind as my last option!

They're usually just an F connector inside a rubber boot to protect from the weather. It's possible that that connection itself is the issue, although unlikely.

contentsofsignaturemaysettleduringshipping