Odd reception problem

fsphil

Hi all!

After the sudden and unexpected relocation of my BBC ariel into my back garden during a storm earlier in the year, I thought I'd replace the whole lot - new cable, taller pole and some nice big aerials. I finally got them up last week but not all is what I expected.

The new RTE aerial is bringing in a fantastic picture without a booster - my freeview box even shows a good DVB signal from Clermont Carn, though oddly finds no channels.

Divis is another matter. It's awful. BBC2 analogue is unwatchable, and the BBC's digital mux is missing completely. BBC 1 analogue is quite good, just a touch of ghosting, Ch. 4 ain't great but watchable. In all it's a fair bit worse than the old aerial. It's in the same location, it's the proper group and the cable has been swapped. To test the aerial itself I swapped it with the one for RTE, and despite being for the wrong group it pulled in exactly the same kind of signal. I even tried an attenuator to make sure the signal wasn't *too* strong.

All I can think of is that something's changed between the old aerial falling down and the new one going up. Some new building somewhere? I've a clear path to the horizon in the direction of both transmitters.

Or perhaps the aerials are just not all that good. Here's the BBC one: http://cpc.farnell.com/jsp/search/productdetail.jsp?SKU=AP00994

I'll probably head down to Argos tomorrow and pick up a cheapy one to try. Anyone any better ideas?

Foggy43

I take it you have a Group A for Divis and a Group CD for Clemount Carn. I wonder did the installer combine the aerials properly. I think it is called a Grp. A Grp. CD Diplexer. Open to correction on this.

Rick_

For the Freeview part, check to see if the DTT box is set to scan for encrypted channels, as even though the channels are free, they have been flagged as encrypted. CH 53 is the only one you'll need to bother scanning though as the channels on CH 57 and CH 60 are all encrypted apart from a few radio channels.

I am having some problems with Divis my self but everything in my set-up seems fine, My analogue picture is OK for all 5 analogue channels as it was before but now when the aerial is plugged into the booster and then the DTT receiver I only get a handfull of channels, without the booster I get everything apart from the MUX that has UTV and Channel 4 etc. on it. It always needed the booster before, so I wonder why there is a sudden change...?

RTE trial comes in fine though with a mostly stable picture, I havn't experienced any real noticable break up or sound drops yet. But my RTE analogue picture is practically perfect for all 4 channels, so even if I couldn't get the trial, all I'm really missing out on is the widescreen pictures.

fsphil

Foggy43 wrote: »

I take it you have a Group A for Divis and a Group CD for Clemount Carn. I wonder did the installer combine the aerials properly. I think it is called a Grp. A Grp. CD Diplexer. Open to correction on this.

Group K for Divis (it covers channels 21-48 I believe). It replaces a cheepy wideband I got from Argus years ago.

The installer better have installed the combiner properly, because I was the installer and I'd be very angry with myself if I didn't I tested both aerials directly with a TV in the attic, nothing between them but the cable. No better.

Paddy C wrote: »

For the Freeview part, check to see if the DTT box is set to scan for encrypted channels, as even though the channels are free, they have been flagged as encrypted. CH 53 is the only one you'll need to bother scanning though as the channels on CH 57 and CH 60 are all encrypted apart from a few radio channels.

Good thinking! It skips anything marked as encrypted. I've a USB DVB receiver somewhere, must dig that out.

Paddy C wrote: »

I am having some problems with Divis my self but everything in my set-up seems fine, My analogue picture is OK for all 5 analogue channels as it was before but now when the aerial is plugged into the booster and then the DTT receiver I only get a handfull of channels, without the booster I get everything apart from the MUX that has UTV and Channel 4 etc. on it. It always needed the booster before, so I wonder why there is a sudden change...?

Hm.. I never considered changes at the transmitter itself. They may have moved the antenna on the mast - I'll see if anyone else in the area has had problems.

fsphil

I got the cheapy wideband from Argus last week and tried getting a signal in the attic, but failed. I just can't get Mux 1 no matter what I do. All the others are weak with the exception of a very strong Mux C.

I also got a new DVB-T receiver (from Lidl) and as a curiosity I pointed the aerial towards Clermont Carn and was surprised to find channels from all four muxes with a really healthy signal strength and quality - despite my neighbours house being in the way! Which just adds to my confusion with the Divis problem At least I get RTE in widescreen now.

Rick_

Where abouts are you fsphil?

fsphil

Ah, forgot to mention that! I'm in Cookstown, Co. Tyrone.