[grantp]

Hi,

I'm in the East Midlands near J24 of the M1. The existing aerial on the house is pointing towards Nottingham. It must be about 25 years old.

Just got a DIGIHOME 915 STB. It picks up UHF channels 29 and 39 fine but nothing else. Reading around I gather this may not be entirely surprising but given our proximity to some large towns and cities I am slightly surprised. The results of what it does pick up are fine and the signal strength seems to be good and better. I have re-run the Initial setup a few times, tried adding channels and tried searching manually as well. No luck. No ITV. Doesn't worry me much as I view rarely but the wife is particualarly put out as all she wanted ot for was one of the channels it doesn't pick up!

I am assuming a new aerial is the most likely fix for the problem but any additional advice, especially if it relates to experiences in my local area would be welcome.

That said I can't get the DIGIHOME unit to fire up the VCR (Panasonic) using the timer. I'll create a separate post for that problem but I'm just wondering if that might indicate a problem with the STB.

Grateful for any input.


Grant

[albertd]

Originally Posted by grantp

I'm in the East Midlands near J24 of the M1. The existing aerial on the house is pointing towards Nottingham. It must be about 25 years old.

Just got a DIGIHOME 915 STB. It picks up UHF channels 29 and 39 fine but nothing else.

The digital transmitter northwest of Nottingham (about 10 miles away) is quite low powered (only 40 watts), and most of the Mux are on high numbered UHF channels, unlike the analogue.

As you have such an old aerial, it is almost sure to be a Group A, which only provides good service up to about Channel 37.

Your most likely solution would be a good vertically polarised wideband aerial mounted as high on the roof as possible. Alternatively, depending upon the terrain, you might be better of with an aerial (also wideband but horizontal) directed east towards the Waltham transmitter.

[grantp]

Originally Posted by albertd

The digital transmitter northwest of Nottingham (about 10 miles away) is quite low powered (only 40 watts), and most of the Mux are on high numbered UHF channels, unlike the analogue.

As you have such an old aerial, it is almost sure to be a Group A, which only provides good service up to about Channel 37.

Your most likely solution would be a good vertically polarised wideband aerial mounted as high on the roof as possible. Alternatively, depending upon the terrain, you might be better of with an aerial (also wideband but horizontal) directed east towards the Waltham transmitter.

Hi Albert,

Thanks for the response. What you have said seems to reflect the way the aerials around here are pointing - some to the North(ish) and the rest to the East - which I seem to recall is the Waltham transmitter.

So as a quick check I could try re-directing the aerial to see what happens (thinking about it I'm not sure it is 25 years old - we had one blow down some years ago - but it certainly is not new.)

On the other hand I suspect loosening the brackets to be able to turn it may be more of a challenge than it is worth.

I'll have to check with the neighbours to see who they used to fit their aerials.

Thanks again.


Grant

[Nigel Goodwin]

If you move to Waltham, bear in mind you need a wideband aerial, as one multiplex is out of band - we have a few customers on Waltham, and when installing IDTV's they are always missing a multiplex.

[grantp]

Originally Posted by Nigel Goodwin

If you move to Waltham, bear in mind you need a wideband aerial, as one multiplex is out of band - we have a few customers on Waltham, and when installing IDTV's they are always missing a multiplex.

Thanks Nigel,

It sounds like I am stuffed as far as using the existing aerial is concerned no matter which way it points.

Hmm. I wonder if my next-door-neighbour's son-in-law is still in the aerial fitting game ...


Grant

[albertd]

Originally Posted by Nigel Goodwin

If you move to Waltham, bear in mind you need a wideband aerial, as one multiplex is out of band

Grant - As I said, wideband is also needed for Nottingham (Ch 29-67). Don't forget about the polarisation as well, it is very important. Vertical for Nottingham, horizontal for Waltham. If you are not sure what I mean, have a look at this:

http://myweb.tiscali.co.uk/albertd/Horiz_Vert.jpg

The top one is horizontally polarised, the bottom one is vertically.

[Ray Cathode]

If you are doing it yourself you can put up two aerials with two downleads?

[grantp]

Originally Posted by albertd

http://myweb.tiscali.co.uk/albertd/Horiz_Vert.jpg

The top one is horizontally polarised, the bottom one is vertically.

Thanks Albert. Very useful. I am sort of aware of the needs but not which source requires which orientation.

I'll be looking at the neighbours aerials now and working out who just has to be using cable!


Grant

[grantp]

Originally Posted by Ray Cathode

If you are doing it yourself you can put up two aerials with two downleads?

That thought occurred to me a couple of hours ago.

The aerial cable is routed into the loft and then splits into 3 (I think - didn't do it myself). One heads to the ground floor, the other two to upstairs bedrooms.

The aerial fitting is mounted on the barge boards at the side of the house. It can get a bit windy there. Not sure the extra resistance of 2 aerials would be a good idea. Especially having lost one before in some gales.

Chap across the road had a large aerial set attached to his chimney stack. 2 metal bands around the stack fitted fairly recently. One broke a few weeks ago and the rig leaned badly until he had it removed while a team was on site fitting new soffits and facias last week. He's on cable so didn't need the aerials any more.

Hmm. Wonder what happened to them ....

Good thought though and worth considering.

Thanks.


Grant

[Sam Radford.]

Originally Posted by grantp

The aerial fitting is mounted on the barge boards at the side of the house.

A cowboy installation. Aerial brackets should be bolted only to bricks or concrete.

[Digi Man]

OP- Have you tried turning the aerial to the west, to see if you can get Sutton Coldfield (West Midlands)?

I live not to far away from where you're living and can get a great reception from Sutton Coldfield.

[grantp]

Originally Posted by Sam Radford.

A cowboy installation. Aerial brackets should be bolted only to bricks or concrete.

I tend to agree though it has always been this way and after the loss was replace in the same fashion.

I think the problem is that the fitters hope to go through the bargeboards into the wall. Not that the walls are that good, this house having been built in the late 70s.

When we had the woodwork replaced a few years ago the bracket was refitted but in pretty much the same way. The reason is that it is the highest point of the roof and at the end of the house. The roof juts out over the wall by about a foot (for those who still use imperial units) and to mount to the (rather dodgy?) wall would mean a large step out bracket and a longer mounting pole to gain the height. My guess is that the loading on that would be as bad as fitting through the bargeboards into the structure (probably a wooden joist) behind. And whilst it would be fixed to brick that in itself may not mean much in this house!

Thanks for the input though. I may ask for something different if I get someone in to change the thing.


Grant

[grantp]

Originally Posted by Digi Man

OP- Have you tried turning the aerial to the west, to see if you can get Sutton Coldfield (West Midlands)?

I live not to far away from where you're living and can get a great reception from Sutton Coldfield.

Hi Digi Man,

No, not tried any changes yet as this only became an issue a couple of days ago following on from Mothers Day last weekend ...

I have heard suggestions about changing to Sutton Coldfield back in the past but as far as I recall no one around here has done so. That said I will scan the skyline tomorrow and see if what I say is true.

I think we may be in a slightly adverse position for SC (slightly on the down slope on the northern side of a small rise) whereas we are relatively beneficially placed for Kimberley (?) or Waltham. I think.

Does SC require vertical or horizontal positioning?


Grant

[Nigel Goodwin]

Originally Posted by grantp

Does SC require vertical or horizontal positioning?

Horizontal, as a rule main stations are horizontal, and relays are vertical - although there are a very small number of horizontal relays.

[SimonBlackham]

Try punching your postcode (and setting DX) into Wolfbane and you will see lots of info in a table relating to the transmitters within DX range - replace the tvd with tva in the address and you will get analogue info.

My digital reception and My Analogue reception ... just bring these up and change to your postcode.

[grantp]

Originally Posted by SimonBlackham

Try punching your postcode (and setting DX) into Wolfbane and you will see lots of info in a table relating to the transmitters within DX range - replace the tvd with tva in the address and you will get analogue info.
.

Simon,

Many thanks - very useful indeed and helps me to understand what the issues are. I'm beginning to understand a little about this technology having previously ignored it (mainly) on the basis that I could find myself becoming obsessed ... Hmm.

Co-incidentally I have just been browsing a technical commentary source for photo colour reproduction and printing articles and found the the two most recent articles deal with HDTV matters - though with a US perspective.

Hmm ... some more.

I'm not sure the rest of the family would be so worried about the finer points of quality though. Simple and few buttons to press seem to be the primary criteria. And I don't suppose the digital programs have any improved content ...

Right - aerial required it seems so something to try to sort out tomorrow.

Thanks all.



Grant

[SimonBlackham]

Obsession is only one of the major diseases dealt with by this forum...

[Pop Roberts]

Originally Posted by grantp

Right - aerial required it seems so something to try to sort out tomorrow.

Whilst you are replacing the aerial fit new low-loss double-screened satellite grade cable. That will also help you get a better signal.

Pop

[grantp]

Originally Posted by SimonBlackham

Obsession is only one of the major diseases dealt with by this forum...

When you say "dealt with" which way should I take that - encouraged or eradicated ?

Grant

[grantp]

Originally Posted by Pop Roberts

Whilst you are replacing the aerial fit new low-loss double-screened satellite grade cable. That will also help you get a better signal.

Pop

Sounds like sensible advice Pop. Thanks.

I assume you mean all the way to the wall socket - an possibly beyond to the STB?

Currently we have a splitter where the cable enters the loft which takes feed off to 2 bedrooms. I assume if I leave those links as they are (low spec kit on the end of the links) it would not degrade the main signal?

Then again I am bearing in mind that the primary user does not seem to be too fussy about quality and in some ways it would be less aggro for me to keep it that way!

I very rarely watch so I don't feel a need to be too critical about the results.


Grant

[albertd]

Originally Posted by grantp

Currently we have a splitter where the cable enters the loft which takes feed off to 2 bedrooms.

Do you mean a plain splitter or a distribution amplifier with two outputs? If it is a plain splitter, that could be part of your problem as it will reduce the signal to both destinations.

[grantp]

Plain Splitter.

Most of the time only one output is in use and at the time the extra links werer installed a few years ago we didn't notice any difference in quality - maybe it was bad already.

I think at the moment it is not a signal strength problem . the 'missing' channels are just not there at all - not even a hint of them if I scan manually. Given that the other links are rarely used (Uni hols sometimes) I'm inclined not to try to get power to that end of the loft just yet and see what happens with an aerial and direction change first .

I'm prepared to re-consider though. Would the splitter alone, but with only one feed in use, degrade an incoming signal enough to cause a complete loss of some frequencies?


Grant

[Nigel Goodwin]

Originally Posted by grantp

I'm prepared to re-consider though. Would the splitter alone, but with only one feed in use, degrade an incoming signal enough to cause a complete loss of some frequencies?

It will certainly degrade it - disconnect it and try it!.

[albertd]

Originally Posted by grantp

I'm inclined not to try to get power to that end of the loft just yet...

If you use a multioutput masthead amp instead of the splitter, you do not have to, because the power for the amp is sent via the coax from one of the viewing points.

[grantp]

Hmm,

New aerial (Televes 45 job iirc - quite large and with head amp) installed on a new mast. New cable into the house as far as the loft where is uses what was there. (at the moment) .

Now pointing at Waltham rather than Nottingham.

First split is 2 way, from which the oldish cable runs down th internal wall to the TV socket. Nor changed as we ran out of time and in any case got quite a good signal - at least we did on digital. Analogue also good except for BBC1 and ITV1 - both of which are average and probably slightly worse than they were.

Second split is a 4 way (1 in 3 out) device with clamped cables.

Only 2 cables out. The first one we have tried has a fairly average picture - but then it's not much of a TV attached either.

Teh weak point seems now to be the TV. Taking the Digihome signal there is some ghosting in the backgraound (noticable on dark screens) which I have established as being elements of whatever analogue channel the TV is tuned to. Take the cable out and the ghosting goes away.

It's not bad but I may get comments from management .... any ideas about fixing or is a new TV (This one is some years old now) the only sensible way to fix it?

Thanks for everything offered so far. Very interesting indeed.

Grant