DIY Satellite Dish Install

[gman76]

Hello All,

Having never dabbled in the world of satellite tv, I thought I would change over to Freesat & install the dish myself.

Set up is as follows: 40cm Raven Mk4 minidish, Zinwell Sky branded Quad LNB, just under 20m shotgun cable to one room, twin run of RG6 to second room, all terminated with Labgear shielded grid F outlets, Humax HDR-1000s on the shotgun cable run. All purchased new.

I "pretuned" the Humax on an existing Sky dish at a different address & had a picture straight away when connected to my dish, using the signal strength meters on the Humax, I aligned the dish to the "sweet spot" & was happy with my work, both tuners showing 90% strength/100% quality.

I used dishpointer website for the direction, a neighboring dish for elevation & the LNB skew is set on position 3.

However, I am experiencing a problem. The signal randomly drops out completely, preceded by a very brief picture & sound break up, during this time, the signal strength meters report no signal on both tuners. The signal does not return on its own.

This evening I was watching ITV1HD (119), signal drops out, change channel to ITV4+1 (118), still no signal, change to S4 (120), signal returns on all channels. This sequence was repeatable.

The issue is much more prevalent just after switching the decoder on.

Owing to the channel change fix, I'm thinking the LNB is at fault?

Or does this sound like a simple dish alignment issue?

Opinions much appreciated!
Thanks in advance.

 

[Lucid]

Try the other two outputs on the LNB first.

 

[gman76]

Cheers Chris, I will do that soon (away for a while now) and report back.

Thanks again for the input.

 

[Sam Gangee]

More tips: http://www.satcure.co.uk/tech/no_satellite_signal.htm

 

[gman76]

Just a quick follow-up:

I had some spare time after all, so I connected the decoder to the other 2 lnb outputs (in the other room) and left it in standby while at work. That night it behaved itself impeccably for an hour or so. I then moved it to the problem room, where it also behaved for the whole evening.

The weather conditions were similar to when the signal has dropped out.

Although this is inconclusive, I still think it's a hardware problem, rather than dish alignment or signal loss in the long cable run. Largely due to the fact that the signal does not return unless the channel is changed. If I hot plug the dish feed, the signal returns immediately.

So, I'm going to order a new lnb, as the original did come from eBay (new) and could be dodgy!

I'll let you know how it goes soon.

 

[Sam Gangee]

I just noticed that you are using RG6 cable. This is generally unsuitable for anything other than very short indoor runs. Despite its low cost, BskyB won't use it - so that must tell you something!

See http://www.satcure.co.uk/accs/RG6_cable.htm

 

[gman76]

Hi Sam,

No, the long run is labgear shotgun from screwfix (not very good), do you think it could be down to cable impedance/volt drop rather than signal loss?

 

[Sam Gangee]

Well, what do you make of this comment about resistance?

"This fact makes the use of RG6 generally risky for LNB connections!"

 

[gman76]

Well, owing to the amount of work involved in replacing the cable - I hate that comment with a passion!

Note for later - do your homework!

 

[Sam Gangee]

Hopefully, it's not the cause of your problem. I never penny-pinch on cable *because* it's a PITB to replace. I'm careful with the connections - use silicone grease on bare copper - and paint the cable to protect it from sunlight.

 

[gman76]

Yes, I hope it's not the cause of the problem. I propose to check the voltage at the wall plate during the fault condition (13 and 18v I believe) lnb under load.

 

[Sam Gangee]

I don't see how you can measure the voltage at the wall plate unless it's the wrong type of plate that has wires exposed (unscreened).
See http://www.satcure.co.uk/tech/wall_plates.htm

 

[gman76]

Yes, they are fully screened, I intend to hook a small gauge insulated wire into the centre pole and carefully close the clamp back down.

 

[Sam Gangee]

That's fine. For a moment you had me worried!

 

[gman76]

We'll, I popped home this afternoon and typically did not get the dropped signal problem. I measured the voltages at the wall plate anyway - 13.2 & 17.8VDC stable.

I also looked into & checked the cable, it is a solid copper centre core. So I am reasonably confident that the cable is not the issue.

Swap out the lnb next do you think?

Many thanks for the input so far BTW.