Possible? SBS on 60 cm dish with 10600 MHz Sky LNB?

Forums › Freeview (DVB-T/DVB-S) › Possible? SBS on 60 cm dish with 10600 MHz Sky LNB?

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Topic # 83474 17-May-2011 13:23

A friend has an unused Sky installation, and I have an unused basic satellite decoder. While she has access to Freeview via UHF, I thought it was worth a try to see if we could get SBS for her as well. The decoder is a Satlink 2800 and worked fine for FV/SBS on my 90 cm dish with my dual output LNB.

There is no label on her LNB - it was oval and "double throated". I guessed it was probably 11300 MHz, or if not that, then 10750 MHz. I tried both of those to no avail.

I repointed the dish by compass and eyeball and shouting, but no good.

Next, I got a sat meter and repointed that way - I was definitely pointing at something (and of course proved that power was reaching the meter), but still no signal.

I tightened the bolts and got off the roof, but thought I'd try just one more thing. I had it in the back of my mind, rightly or wrongly, that some Sky LNBs were 10600 LO. I gave that a go and presto! Freeview reception, but no SBS. At least I could be confident I'd found Optus D1 though.

Next time, with the aid of some wireless intercoms with her watching signal levels on the TV display and relaying them, I tweaked the dish alignment, focus, and skew, trying to optimise the level for SBS - no joy.

I gave up again, having only made things worse as there is now no DVB-S FV reception either. That's no big deal of course as she has UHF.

So, my current thinking is:
- the 10600 LNB can't handle V polarisation (there's no other box holding it in H),
- it's old and weak, or
- the dish is just too small to do the job.

There's probably a budget for a new LNB at around $20 or so, but a bigger dish isn't worth the cost for the additional benefit she'd receive from two more channels that could disappear any day (good though they are).

Any thoughts?

1 | 2

6739 posts

Uber Geek
+1 received by user: 593

Trusted

Reply # 470099 17-May-2011 13:41

Ah, post got lost......

Skew, go back and patiently adjust this.

LNB is probably the problem, the dual/oval ones are failing now and the different frequency hints at that being a problem.

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470112 17-May-2011 14:17

Thanks Jaxson.

So - with all bits working and correctly oriented, a 60 cm dish should bring in enough signal for SBS, is that right?

(Cable run isn't very long - maybe 15 m)

Are you thinking it was a 10750 LNB that has drifted? I thought there were some that were intentionally 10600 - is that not the case?

Would it work to optimise everything except skew using one of the FV transponders first, and then tweak the skew for SBS?

nitrotech

1233 posts

Uber Geek
+1 received by user: 154

Reply # 470115 17-May-2011 14:26

Yep a 60cm dish will pick it up (in some places in NZ anyway) - remember that SBS is the opposite pol to freeview so if you've got a single pol LNB you'll need to skew by 90 degrees to pickup SBS.

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470117 17-May-2011 14:30

Yeah - I wondered about whether that was a possibility - that the LNB that is there is single polarisation only and rotation being an option.

Did Sky ever install single-pol LNBs? This one is about 5 years old, my friend says. I looked twice but couldn't see any label on it unfortunately.

Jaxson

6739 posts

Uber Geek
+1 received by user: 593

Trusted

Reply # 470118 17-May-2011 14:31

xarqi: Thanks Jaxson.

So - with all bits working and correctly oriented, a 60 cm dish should bring in enough signal for SBS, is that right?

Are you thinking it was a 10750 LNB that has drifted?

Would it work to optimise everything except skew using one of the FV transponders first, and then tweak the skew for SBS?

Yes to all these questions.

Tweak away with the freeview transponders. Freeview is much stronger so if you can't get that then you have bigger problems than SBS.

The skew needs to be spot on for SBS given it is so weak.

I'd be budgeting on a new LNB, keeping that at the back of your mind.

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470119 17-May-2011 14:36

OK - thanks people. I have an action plan.

Next time - back on the roof and align and tweak based on FV transponder.
Try tweaking skew a little to see if I can get SBS.
Try tweaking skew a LOT (90 degrees) to see if I can get SBS even if I lose FV.
Try a new LNB.
Give up.

nitrotech

1233 posts

Uber Geek
+1 received by user: 154

Reply # 470132 17-May-2011 15:05

xarqi: OK - thanks people. I have an action plan.

Next time - back on the roof and align and tweak based on FV transponder.
Try tweaking skew a little to see if I can get SBS.
Try tweaking skew a LOT (90 degrees) to see if I can get SBS even if I lose FV.
Try a new LNB.
Give up.

You won't get SBS tweaking a little - SBS is a full 90 degrees different to freeview (h pol) UNLESS you are searching V pol.

I suggest:

1) Make sure you get freeview

2) Skew LNB another 90degrees

3) Do a seach on the SBS sat freq - if nothing then make small adjustments to skew

Should work fine

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470137 17-May-2011 15:19

The idea of tweaking a little was if the LNB was in fact capable of V-pol operation, but as per Jaxson's post, precise skew setting being needed. That would be marginally preferable as it would be a more standard installation then, and the few services on satellite Freeview that are not on terrestrial FV could be accessed.

Failing that, tweaking a lot may make a single-pol LNB do the job. Can anyone confirm whether Sky ever installed single-pol LNBs?

Gilco2

1493 posts

Uber Geek
+1 received by user: 124

Subscriber

Reply # 470147 17-May-2011 15:44

Hi yep you will get it. I have a 60cm dish with freeview and 10750 lnb and I get all freeview and SBS. Because I have the Ultraplus F-9000HD I also get the SBS HD. This is at Papamoa

HTPC Intel Pentium G3258 cpu, Gigabyte H97n-wifi motherboard, , 8GB DDR3 ram, onboard graphics. Hauppuage HVR 5500 tuner, Silverstone LC16M case, Windows 10 pro 64 bit using Nextpvr and Kodi

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470149 17-May-2011 15:52

Good to know. Looks like the dish will do the job then. It's in pretty good nick and the line of sight to Optus D1 is unobstructed.

I'm almost tempted to order up a new LNB right now, but I'll have one more go at it with what's there first. It may not be for several days, but I'll report back on progress.

Brunzy

699 posts

Ultimate Geek
+1 received by user: 75

Trusted

Reply # 470231 17-May-2011 19:42

xarqi: OK - thanks people. I have an action plan.

Next time - back on the roof and align and tweak based on FV transponder.
Try tweaking skew a little to see if I can get SBS.
Try tweaking skew a LOT (90 degrees) to see if I can get SBS even if I lose FV.
Try a new LNB.
Give up.............Hire a pro

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 470234 17-May-2011 19:51

Brunzy:
xarqi: OK - thanks people. I have an action plan.

Next time - back on the roof and align and tweak based on FV transponder.
Try tweaking skew a little to see if I can get SBS.
Try tweaking skew a LOT (90 degrees) to see if I can get SBS even if I lose FV.
Try a new LNB.
Give up.............Hire a pro

Hire a pro?
Maybe you didn't get the memo.
The plan here is to use what bits are available to pick up SBS if possible. It may be worth spending $20 on an LNB, but that's about it.

Know any pros who'll do the job for $10?
I'm guessing not, but if you did, I wouldn't want to hire any professional with such a low sense of self-worth anyway.

kiwisat

147 posts

Master Geek
+1 received by user: 2

Reply # 473159 23-May-2011 20:33

Unfortunately, the Satlink 2800 has one the weakest tuners on the market. I have been selling a 45 cm dish for 4 years now, and whereas the Satlink 2700 performed very well with the small dish, the Satlink 2800 struggled. As part of the installation instructions I supply with the dish are tuning details for SBS, quite do-able on a 45 cm dish with a good LNB (I supply an MTI 11300 Mhz, 0.2 db), which then ensures a perfect alignment with D1 for all freeview and/or sky signal. With respect to the old dying Sky LNB, replace it with something decent, and try any other freeview receiver on the dish.

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 473183 23-May-2011 21:35

Thanks for that information! If SBS is feasible with a 45 cm dish and a decent LNB and tuner, a 60 cm dish, giving about 80% greater capture area may allow even the comparatively weak tuner in the 2800 to do the job.

I haven't got back to my friend's yet to have another go, so I have no news. It'll be worth it to try a new, cheap LNB, but not a different receiver. It's only because I had a spare that might do the job essentially for free that it was worth trying at all. Since she has Freeview via UHF, it's not really worthwhile spending anything on a new receiver or dish.

xarqi

727 posts

Ultimate Geek
+1 received by user: 7

Reply # 473744 24-May-2011 23:09

I went ahead and got a new LNB since I think the case is strong that the existing one is knackered. I think I may have a problem though. The one I got, like most, has a 40 mm throat diameter, but I have a sinking feeling that when I get up on the roof of my friend's house to install it, I'm going to find that the bracket there is 22 mm.

What would my options be?
Can I bend the existing one to fit?
Can I remove the existing bracket and use a bit of good old #8 wire instead?
... and, if push comes to shove...
Who sells cheap 40 mm brackets that will go on a Sky dish? I can't see any on TradeMe.

(Nothing's ever simple, is it?)

Edit:
Grrrrrr!
I had a better look at TradeMe and found that the person from whom I bought the LNB also has brackets for $8. I could have saved an extra courier charge. Maybe I'd better buy some connectors too.

Still open to other ideas though.

1 | 2