Signal Loss when Sunny

**garym71** · 21-06-2009

I have a 70cm Raven Gemini dish with 3 LNBs on (my setup can be seen HERE). In the mornings when it's sunny the signal level on some channels drops low enough that we completely lose the signal on those channels.

As the sun moves round later in the day the problem disappears so the key factor appears to be the location of the sun. At the time when we lose the signals the sun is in the south-east directly above where the dish is pointing. If clouds come across and cover the sun then the signal comes back again. When the clouds move away again exposing the sun the signal gets lost again. If there is no clouds in the sky at all then we won't be able to get a signal until at least mid-day when the sun has moved far enough round to the south, away from the azimuth of the dish.

This doesn't happen on all channels, just some of them. On those channels the signal strength is usually ~70% when we're receiving a good signal but when the sun is above the dish this drops below 50% thus causing the signal to be lost completely.

Is this a "known" problem when the sun is above the dish (is do, why does it happen?) and is there anything I could do to try and prevent this happening so we can watch those channels reliably on sunny mornings?

Thanks.

**rolfw** · 21-06-2009

Does it happen on all three satellites? The skew on 19 and 13 East looks to be too much, perhaps this is a problem, unless of course the LNBs are pre skewed.

**satelliteman** · 21-06-2009

Those MTi LNb's are at a 45° angle when skewed at zero Rolf.

**rolfw** · 21-06-2009

Thought that might have been the case, they are also crap in my experience, stopped using them a long time ago.

So perhaps they ought to be a little more skewed then.

**satelliteman** · 21-06-2009

Yes, identifying what satellite/s the fault appears on would be useful.
Could be the LNb/s itself that's failing; there cheap enough to at least try and see.

***Huevos*** · 21-06-2009

We suffer the sun effect here twice a year for a couple of weeks (on 28 east). Doesn't make any difference if it is cloudy (cloud would effect radio noise from the sun the same amount as wanted signal, so the overall C/N ratio would be the same). It lasts about 15 minutes on the worst days. That means the sun is less than 2 degrees from the dish axis when the effect starts to occur.

In your location at this time of year the sun doesn't come within 30 degrees of 28E, 19E and 13E so there is no way that radio noise from the sun is the cause. The only other possibility I can think of, related to the sun, is that dish deforms when hot. I've never heard of this though.

**Analoguesat** · 21-06-2009

Sounds like the heat from the sun is pushing the internal oscillators out of tolerance. Swap the affected lnb's for some decent ones.

**garym71** · 22-06-2009

Thanks for the replies

The skew is pretty much spot on and as already mentioned, the single output MTI LNBs always look a bit odd because with zero skew the F-connector socket comes out at a 45 degree angle.

We mainly watch the Russian channels on 13.0E (single ouput LNB) so I'm not sure about the channels coming in on the other single output LBN pointed at 19.2E as we don't regularly watch anything on that one to be honest. The quad output LNB at 28.2E is also used to feed our Sky+ box and we NEVER have any loss of picture on with any channel on that no matter what the time of day is or if the sun is in/out. The strange thing is that it is only 2 of the Russian channels on 13.0E that completely lose their signals while the others remain fine (although still with a lower percentage quality, just not enough for the signal to be lost).

I'm willing to try swapping the MTI LNB's for some better quality ones to see if this resolves the problem. Any recommendations on the best ones to get?

**satelliteman** · 22-06-2009

A long list, Inverto or Invacom have good reports.

**rolfw** · 22-06-2009

Get a couple of Inverto LNBs, cheap and perform well.

***Huevos*** · 22-06-2009

Inverto Black Ultra.

**garym71** · 22-06-2009

I'm glad you the Invertos have been mentioned because I was doing a bit a research last night and they do seem to get good reviews. They also do a range with a black casing which would be perfect for my all black setup

I think I'll try a couple of the Black Ultra (IDLB-SINL40-ULTRA-OPP) ones as the general concenus seems to be that they're pretty good. The only downside is that they still don't appear to be any UK sellers for these so I'll have to get them from Europe.

Thanks again for your input

**HB13DISH** · 22-06-2009

Originally Posted by garym71

I'm glad you the Invertos have been mentioned because I was doing a bit a research last night and they do seem to get good reviews. They also do a range with a black casing which would be perfect for my all black setup

I think I'll try a couple of the Black Ultra (IDLB-SINL40-ULTRA-OPP) ones as the general concenus seems to be that they're pretty good. The only downside is that they still don't appear to be any UK sellers for these so I'll have to get them from Europe.

Thanks again for your input

If you can't buy it in the UK, it is available from hm-sat.de at 19.90 Euro
Are you sure you want a single output?
Shipment cost is a bit high last time I checked.
_http://www.hm-sat-shop.de

**Analoguesat** · 22-06-2009

I like MTI Blulines

Cheap cheerful and work fine for strong signals off the European sats.

**garym71** · 25-06-2009

@HB13DISH - As I have a fairly simplistic setup for practical rather than experimental use, I have no plans to expand to additional boxes thus the reason I only need single output LNB's pointing at 13.0E and 19.2E.

@Analoguesat - Thanks for the advice on the MTI Bluelines. However, as I already seem to have had some issues with the MTI LNBs (athough be it the cheaper models), I've decided to just change brand completely and go for the Invertos this time. The Invertos get mostly good reviews so I think I would be very unlucky if I ended up with a worse setup than I already have from LNBs that cost more.

I emailed Satcure to see if they could get me any of the Inverto Black Ultra (IDLB-SINL40-ULTRA-OPP) LNBs but they replied saying it would only be profitable for them to buy those LNB's in bulk quantities of 100 at a time and they didn't think there would be enough demand for them to justify stocking that many units which meant unfortunately they couldn't help me.

I have therefore now ordered a couple of them from German supplier satshop.tv which worked out at 11 Euros cheaper than hm-sat.de after the VAT and delivery charges had been added. They should be with me by the weekend.

I will post an update with the results once I've got them fitted them

**garym71** · 14-07-2009

Just a quick update...

Be aware of ordering anything from satshop.tv. I received the LNBs two weeks ago but one of them was not what I'd ordered. I've sent 3 emails to satshop.tv over the past week and a half (both via direct email and also using their web based contact form) but have received absolutely nothing back, not even acknowledgement of my problem. All I've received is an automated email asking me to leave a review about the products I purchased. I don't think so...not until I've at least received the correct goods. Very poor customer service indeed and the fact they are in another country doesn't really help.

Thankfully I paid by PayPal so I guess I'll give them another week and if I still receive no correspondence back from them I will have no option but to raise a dispute with PayPal over the issue

Has anyone else had any dealings with this company?

**garym71** · 10-10-2009

Well nearly 4 months later after a load of grief with satshop.tv, I finally purchased some new Inverto Black LNBs from a UK supplier instead. I fitted them last weekend and difference they have made is almost unbelievable.

Where I was previously only ever getting 70% on a good day with the MTI LNBs and no signal (~22%) with the sun directly above the dish, I am now getting 90% with the Inverto Black LNBs on the same channels with no signal loss or reduction in the signal percentage whatsoever with the sun directly above the dish. So by simply changing the LNBs for better quality ones my problem has been solved.

Thanks to the other members on here for pointing me in the right direction

With regards to satshop.tv supplying me with an incorrect LNB, I was never able to get this resolved even with months of trying so I eventually just decided to cut my losses and give up. PayPal weren't interested in helping me and much to my disappointment neither were Barclaycard whose credit card I used to pay for the goods through PayPal. In the end I just decided to purchase a different model of Inverto LNB instead that was readily available from a supplier in the UK. This is unfortunately why it's taken so long to get my signal problem sorted out but at least it's fixed at long last

***Tivù*** · 10-10-2009

Well thanks for coming back to us with the outcome.

All in all, a decent result, despite the small holes in the pockets!

**satelliteman** · 10-10-2009

Yes, nice result garym71

***Vipersan*** · 10-10-2009

A very 'unhelpful' reply from me is warranted I think

I can honestly say I have _NEVER_ seen this 'sun effect' thing ..
But then ...

I live in Manchester..
Now where's that light switch

**zoro25** · 10-10-2009

Originally Posted by garym71

I finally purchased some new Inverto Black LNBs from a UK supplier instead.

Thanks to the other members on here for pointing me in the right direction

I'm also on the look out for an inverto black LNB but can't seem to find any UK suppliers,

Can you please pass on the site you got your one from.

***Vipersan*** · 10-10-2009

Southern Satellite stock duo's and quads ...
just checked their Ebay

shop with a search for
'inverto black lnb'
rgds

**satelliteman** · 10-10-2009

You can find southernsat here also.

**garym71** · 10-10-2009

Yep, I got my Inverto Black Quad LNB from Southern Satellites on Ebay

. They only seem to do the Premium range though and not the Ultra range so if it's the Ultras you want then you will still have to look at getting those from Germany unfortunately.

***Huevos*** · 10-10-2009

Originally Posted by garym71

Yep, I got my Inverto Black Quad LNB from Southern Satellites on Ebay. They only seem to do the Premium range though and not the Ultra range so if it's the Ultras you want then you will still have to look at getting those from Germany unfortunately.

The Premium is just a good LNB, the Ultra is the absolutely best fringe reception LNB. There's probably nothing on the market that touches it in this capacity.

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Signal Loss when Sunny Information exchange on LNBs, Single satellite, motorised and multi-satellite systems. DiSEqC switches, positioners, motors, actuators, dish-alignment etc.

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