All posts by Jonathan
Below are all of Jonathan's postings, with the most recent are at the bottom of the page.Jim F: Thanks for your attenuator suggestion. Your theory sounds very plausible, as we have two signal boosters - one on the (very high) roof aerial itself and another in the loft - that were necessary before Mendip's switchover. (We live behind a hill.)
It may be that the signal would now benefit from permanent attentuation, as we are still getting traffic interference (also boosted I presume) on some PSB channels, notably C4, but I'll try it first just for retuning. I presume that a variable attentuator would be best, esp. if it may be needed permanently. Most seem to be 20db max - would it be worth spending more on a 25db max?
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Jim F: Thanks for the further advice. Our boosters were actually for the digital signal (analogue was fine!) before Mendip itself boosted the power - on PSBs - at switchover. Of course, the problem is that they've always boosted the traffic inteference too, which used to be far worse before switchover, so I doubt the coax has deteroriated. The entire system was checked or modified three times by different professional engineers, and there was no real improvement until Mendip's switchover, and then only on PSBs. For almost 10 years, digital TV here was only watchable during the middle of the night.
After switchover, we did try taking out the loft booster but then the signal disappeared completely on all channels. The booster on the aerial itself is almost inaccessible; the roof is so high and dangerous that even experienced engineers are reluctant to go on it!
The variable attentuators on eBay seem to go up to 25db, but these cost quite a bit more than the 0-20db ones.
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Jim F: Yes, there's a masthead booster and a loft booster (just for the one receiver). I can't recall exactly what happened when we tried to remove the loft booster - I didn't do it personally, but I think we tried different ways of re-connecting it, then just let it remain.
Since switchover, I've been almost happy with the stronger PSB channels, but sometimes during afternoons - and particularly when rainy - the traffic interference will occur maybe 3-4 times an hour on Channel 4 (and the weaker multiplexes). We live on an increasingly busy crossroads and the interference can usually be linked to mopeds, passing or waiting at the junction. I haven't tried monitoring the signal strength when it happens (I rarely watch live TV).
I tried the variable attenuator (at different settings) yesterday while trying to save the Arq B channels, but the Panasonic - while finding them easily - still refuses to install them, whether on the normal full signal strength or anything lower. Maybe I'll have to try a full re-tune but I worry I'll lose the other muxes too. I think I'll ask on AV Forums to see if anyone else has trouble re Mendip and Panasonic equipment on UHF 67.
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I retuned yesterday to C49, got all its channels at full strength and quality all day, even after switching off and on again... This morning (9.20am) they have all vanished - blank screens/"no signal" - though it still claims 10 for strength and quality on the tuner for C49. Other multiplexes okay. Has the maintenance work on PSB1 resumed?
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I had to do a second (manual) retune to get C49/PSB1 back - but I've no idea why those stations (and no others) were lost overnight after they'd been accessed and stored yesterday.
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Tuesday 15 March 2011 1:35PM
Radstock
I'm trying to manually tune my Panasonic recorder (EX768) into channel 67 in order to regain the Arquiva B stations that used to be on 59. When I scan for them, all channels come up with 10 for both signal quality and strength, but after I press EXIT (as directed in the handbook) none of the stations are saved.
(This manual tuning process worked fine after the analogue switch-off - when it was necessary because the auto-tune saves only Stockland Hill channels, not Mendip, with loads of interference.)
I've tried disconnecting everything except the Scart lead for the (analogue) TV. I'm reluctant to do a complete re-tune again, in case I'm unable to save even PSB channels after I've cleared them. I have no other digital receivers to compare.
Any other suggestions, please?
Curiously, my DVR is Panasonic, bought 2010, and I live in Midsomer Norton - all similar to Andre Fournier above.