Full Freeview on the Winter Hill (Bolton, England) transmitter

_{sentiment_very_satisfied}Platinum

1:56 PM

: Well done. Is you surname Bean by any chance? Are you looking for an award?

Sunday, 8 December 2013

Barry
11:18 AM
Chorley

I was hoping for any clues as to why the BBCA mux is not receivable on an indoor (43db ) whereas the other Mux's are fine.

Is the array for BBCA lower down the for instance?

Barry's 4 posts

_{sentiment_very_satisfied}Platinum

3:41 PM

: With knowledge of your location why on earth do you think this might be a weaker ???!!!

The terrain plot suggests you have clear line-of-sight at 7.6 miles. The is 100kW on all !

Your problem could be that the signal is too strong and that "the right angle" is one where the strength is a little lower.

As for an that has 43dB , I doubt there is such a thing. The claim is presumably one put there by marketeers and applies to a device which combines an antenna and (which as a whole is referred to as an "aerial").

If this has a variable amplifier then I would start by turning it down to minimum and work from there.

Providing it is sited in a room with good , which is preferably with as few a walls in the way in the direction of the transmitter as possible, then something like this should be suitable:

SLx Indoor Digital Aerial ANR310 UHF DAB Fully Flexible Caravan Motorhome | eBay

I have one of these and received television before , when the transmission was lower than now. I am 25 miles from with a relatively clear signal path (the top of the tower being visible above the horizon from a nearby railway bridge) and the signals were radiated at 20kW.

Barry
3:57 PM

The only mux that is a problem is BBCA. It would seem that there is line of sight to the . I am at a loss as to why the one mux is being received at a lower level than all the rest.
I have tried the amp at minimum and another indoor with a lower claimed .

Barry's 4 posts

jb38

_{sentiment_very_satisfied}Platinum

5:26 PM

: Purely with reference to your question regarding the TX , the PSB transmission aerials (panels) are always located at the top of the mast and as such can sometimes be received in a not too distant location at a "slightly" lower strength than that of the other transmitters radiating from lower down the mast, the "over the head" effect being totally dependant on the terrain, and of course with the reverse situation sometimes being the case if the receiving aerial is located on high ground.

jb38's 7,179 posts

_{sentiment_very_satisfied}Platinum

6:40 PM

: Different frequencies travel differently which explains why all signals broadcast from the same place and at the same can be received at different levels.

As jb38 says, you could potentially be affected by the "umbrella effect". This is where the high power focuses the beam further away - which is towards its horizon. This is opposed to focusing on the ground closer to it.

If you can then use the . This may provide more stable anyway.

MikeP

_{sentiment_very_satisfied}Platinum

8:57 PM

Most main sites use 'trapezoid slot' aerials which are positioned around the cylindrical sleeve (weather protection) so radiate equally in all directions. A typical array has a number of such slots around the circumference and stacked in a slightly staggered pattern to ensure equal radiation in all directions. Each slot aerial radiates *all* the signals for *all* the multiplexes so there is not significant difference in radiate pattern or density.
It does differ on the smaller 'repeater' or ' light' transmitters as they are required to me more directional.

MikeP's 3,056 posts

_{sentiment_very_satisfied}Platinum

9:19 PM

MikeP: That's interesting because the heights given for PSB and COM channels of some of the high- transmitters are different where they are all at the same power, e.g. . The latter is usually slightly lower down.

I'd read into this that there are two different arrays, perhaps with the latter having the beam tilted lower than the latter. (I note that all six of 's are 726m. 's are all the same.)

The main transmitters where the COMs run at half power to the PSBs generally have all six muxes at the same height which would suggest that they all use the same array, presumably because the additional cost of a second array isn't seen as worthwhile and that reducing the power is a more economical way of reducing the coverage footprint (so as to reuse the channels).

Monday, 9 December 2013

Ste
1:35 PM
Prescot

L35 8PT.

Hello.

I'm experiencing an odd problem on only.

On HD, there's an occasional black flash on the , almost as if someone walked in front of the camera. Sound is uninterrupted.

There can be no problem for a while, then these flashes will occur several times a minute.

Any clues as to where to look?

Thanks.

Ste's 5 posts

Briantist

_{sentiment_very_satisfied}Owner

3:31 PM

Ste: I would have a look at the Freeview intermittent interference | Freeview Interference | ukfree.tv - 11 years of independent, free digital TV advice page first.