LNB problems

Paul came with me today to a job about fifty miles from home. On the way he was telling me about his analyser, which had a faulty battery. After ten minutes the low battery warning would come on. He mentioned that just before the battery finally dies the satellite tuning drifts about 10MHz. I vaguely remembered that peculiarity from the days when that analyser was mine. Then we were distracted by an unmarked police car (a dark blue Volvo estate with blue bulbs inside the reversing lights) pulling some hapless idiot sales rep who’d recently passed us at about 110mph. We cheered as we passed.

Anyway we got to the job, which was at a huge industrial factory-type place. It was actually a food warehouse and they were so scared of terrorists getting in and contaminating the food that security was very high. It took ages to get through the site induction as well, and getting onto the roof was a navigational and diplomatic nightmare, but eventually we were on top of this enormous building – just to fix a bog-standard Sky dish!

Paul lined the dish up and then decided to check the Bit Error Rate (or Ratio if you’re posh) on a few sample muxes. “Your analyser’s the same as mine,” he said. “It’s gone off tune. The battery must be flat.” Now I knew that the battery was at least three hours away from flat and as far as I knew the machine doesn’t drift when the battery runs down, it just announces its plight and switches off in an orderly matter.

I looked at the spectrum display and all the muxes were about 10MHz low frequency. I could check the BER but only after manual tuning. The presets for Astra didn’t coincide with the muxes. “Well it’s either the analyser, the LNB, or maybe the solar panels on Astra are packing up” I said.

“Ha ha!” said Paul between gritted teeth. I switched to low band and the muxes were all OK, so I knew it wasn’t the analyser, because it simply superimposes a different channel set when you change band or satellites. The sun was shining brightly so I thought “Well, even if the solar panels on the satellite aren’t very good I should think they’d work OK on a lovely day like this. So it must be the LNB.”

“It must be the LNB” I said aloud.

“Why were you looking at the sky?”

“Err, just thinking. Go get another LNB. You’ll have to rob the spare Sky dish.” So off he trotted. I rarely use domestic Sky dishes so I’d put two in the van, just in case we dropped the first one. Lucky I did.

It was going to take him ages to get down to the van and back, so I cleared up the mess we’d made and then made a few pointless phone calls. Finally the replacement LNB arrived and was fitted, and I said “That’s OK now. Hang on, I’ll just check everything . . . bugger! BUGGER! There’s no low band!”

“There isn’t another dish in the van” said Paul. “Have you got any loose LNBs?

“Yes. I’ve got two quads, two quatros, four single output, but none of them will fit on a minidish.”

“Bugger.”

So I went down to the van that time, racking my brains as to whether I’d got a Sky LNB anywhere. At the van I opened the box containing one of the single output ones, and found that the manufacturers had changed the design, and an adaptor was now included so the LNB would fit onto a minidish. Hurray! The day was saved. I wouldn’t have to go round that God-forsaken town trying to buy an LNB. The third LNB worked fine.