Best Site for Freeview Transmitter Info.

JohnB47

Neil_Jones said:

JohnB47 said:

Well that seemed to go OK, with most mux channels showing good quality and strength, apart from Ch45 which was poor on both. It did manage to tune to Ch45 though and the picture quality looked OK when I viewed it. Favourites and recording list is intact.

Just wondering - on a day with good weather (a bit cloudy but with some sun, no rain), why would the reception on just one mux feed be poor? It's sometimes that one channel that shows no signal, again on days when the weather is not unusually bad.  Does that suggest that there is still work to do on my aerial/amplifier?

It doesn't seem right that this should be 'normal'.

Channel 45 on Freeview is Gems TV.

This is on what is called COM5, or the Commercial Multiplex number 5.

In a nutshell this is how Freeview can have so many channels, even though there are only seven multiplexes.

Need to work out if the same problem occurs on all channels carried on COM5 or if its just one of them.  Other channels on COM5 on Freeview are (amongst others) Dave, Sky News, Challenge and 4Seven.  If it does that may suggest an aerial alignment issue, or there's some other obstacle in the way like a tree or something.

Note that the signal quality and strength doesn't necessarily mean anything, as different TVs measure this in different ways.  Probably better that you can see a stable picture.

Ah hang on. Sorry if I wasn't clear.

All along I've tried to use the word channel to mean transmitter mux channel. However, my last post implied TV channel.

I really meant any TV channel using transmitter mux channel 45 is unreliable. A pity the word channel can be used for mux and TV.

PHK

JohnB47 said:

Neil_Jones said:

JohnB47 said:

Well that seemed to go OK, with most mux channels showing good quality and strength, apart from Ch45 which was poor on both. It did manage to tune to Ch45 though and the picture quality looked OK when I viewed it. Favourites and recording list is intact.

Just wondering - on a day with good weather (a bit cloudy but with some sun, no rain), why would the reception on just one mux feed be poor? It's sometimes that one channel that shows no signal, again on days when the weather is not unusually bad.  Does that suggest that there is still work to do on my aerial/amplifier?

It doesn't seem right that this should be 'normal'.

Channel 45 on Freeview is Gems TV.

This is on what is called COM5, or the Commercial Multiplex number 5.

In a nutshell this is how Freeview can have so many channels, even though there are only seven multiplexes.

Need to work out if the same problem occurs on all channels carried on COM5 or if its just one of them.  Other channels on COM5 on Freeview are (amongst others) Dave, Sky News, Challenge and 4Seven.  If it does that may suggest an aerial alignment issue, or there's some other obstacle in the way like a tree or something.

Note that the signal quality and strength doesn't necessarily mean anything, as different TVs measure this in different ways.  Probably better that you can see a stable picture.

Ah hang on. Sorry if I wasn't clear.

All along I've tried to use the word channel to mean transmitter mux channel. However, my last post implied TV channel.

I really meant any TV channel using transmitter mux channel 45 is unreliable. A pity the word channel can be used for mux and TV.

Actually it's the other poster who got their terminology wrong. 

You correctly referred to Ch 45 the frequency the mux is on , they were confusing channel with lcn 45 being the number to be entered for TV service Gems TV

Heedtheadvice

I would not ignore the signal level info. It will not be perfect but if you find it low then manual retuning for that only might find you better reception especially if you have a choice of transmitters.

Although we are in the digital world signals from transmitter to receiver are still subject to variations from weather, tides, foliage,  poor alignment, rejection of other transmitter signals, sun spots etc. Being digital rather than quality variation they are on/off resulting in signal levels ok or not ok being pixilated or totally on off.

It might be better using some of the signals from your adjacent tx?

Neil_Jones

Yeah its confusing sometimes because the muxes usually (with a handful of exceptions) follow the same channel numbers the old analogue TV services were on, which is in the range 21-68, but that doesn't mean you'd have have access to 47 channels under that system, it was done  for a reason.

But otherwise, if your COM5 signal is on UHF channel 45, and your issue affects all the Freeview channels on that frequency, but everything else is oaky, that's either a setup or aerial issue.

PHK

Neil_Jones said:

Yeah its confusing sometimes because the muxes usually (with a handful of exceptions) follow the same channel numbers the old analogue TV services were on, which is in the range 21-68, but that doesn't mean you'd have have access to 47 channels under that system, it was done  for a reason.

But otherwise, if your COM5 signal is on UHF channel 45, and your issue affects all the Freeview channels on that frequency, but everything else is oaky, that's either a setup or aerial issue.

If you recall the government sold off TV spectrum, so the range hasn't been 21-68 for some time now.

cerebus

There's a good chance you no longer have the correct aerial for your area as things have changed over the years since you last had your aerial installed

Do you need an amplifier to boost the signal as you are so far from the transmitter or are you supplying multiple tvs?

What's your location/how far are you away from beacon Hill?

Any chance of a pic of your aerial?

JohnB47

cerebus said:

There's a good chance you no longer have the correct aerial for your area as things have changed over the years since you last had your aerial installed

Do you need an amplifier to boost the signal as you are so far from the transmitter or are you supplying multiple tvs?

What's your location/how far are you away from beacon Hill?

Any chance of a pic of your aerial?

Thanks. Sorry, I haven't checked this thread for a while.

Beacon Hill is apparently 25 Km from my house. It feeds just one TV and HDR (both Panasonic). The amplifier was fitted when the aerial was fitted some years ago (at least 15?) and I was told then that an amplifier was needed. The amplifier became faulty about a year or two ago (a retaining strap broke and it filled with water) and was replaced by 'a better one' . I asked again if an amplifier was really needed (this was a different fitter) and he said yes. I still have my doubts but I'm not an expert.

At that time I also said I thought the aerial wasn't aligned with Beacon hill - it wasn't pointing in the same direction as most other aerials in my area. The guy did some checks and did rotate the aerial.

At that point I thought I'd done everything I could. But I'm still not getting good reception on some mux channels - mostly but not exclusively, mux 45.

I'll try posting a picture of the aerial later. It's a pity I can't take the amplifier out of the circuit, to do a test, but I'm not going up a ladder!

cerebus

JohnB47 said:

cerebus said:

There's a good chance you no longer have the correct aerial for your area as things have changed over the years since you last had your aerial installed

Do you need an amplifier to boost the signal as you are so far from the transmitter or are you supplying multiple tvs?

What's your location/how far are you away from beacon Hill?

Any chance of a pic of your aerial?

Thanks. Sorry, I haven't checked this thread for a while.

Beacon Hill is apparently 25 Km from my house. It feeds just one TV and HDR (both Panasonic). The amplifier was fitted when the aerial was fitted some years ago (at least 15?) and I was told then that an amplifier was needed. The amplifier became faulty about a year or two ago (a retaining strap broke and it filled with water) and was replaced by 'a better one' . I asked again if an amplifier was really needed (this was a different fitter) and he said yes. I still have my doubts but I'm not an expert.

At that time I also said I thought the aerial wasn't aligned with Beacon hill - it wasn't pointing in the same direction as most other aerials in my area. The guy did some checks and did rotate the aerial.

At that point I thought I'd done everything I could. But I'm still not getting good reception on some mux channels - mostly but not exclusively, mux 45.

I'll try posting a picture of the aerial later. It's a pity I can't take the amplifier out of the circuit, to do a test, but I'm not going up a ladder!

Thats pretty close! Can't see why you need an amplifier unless line of sight is compromised especially as you're only supplying one telly

With the correct aerial,  correctly aligned, pointing slightly up and with a decent drop cable (what cable has been used) at a decent height , then there should be no issues with any muxes.

For example I fitted a log periodic supplying three tellies around 25 miles from the transmitter,  with no amplifier and I get great signal on all tellies 

cerebus

Forgot to ask what circuit is your masthead amplifier supplied from?

JohnB47

Hmm. No idea about cable type - how would I tell that? The Amp is plugged into the ground floor socket ring, same as TV/HDR/Router/Firestick/Table and floor lamps. I guess you're thinking about interference. But what I'm experiencing is 'no signal'. Sometimes its just for a few seconds and the picture appears then goes again. Other times it's more long lasting, like mux 45 has actually stopped transmitting but I'm sure it's not that. I don't think mains born interference would do that. 

I still need to take that photo.

I suppose I'm right that you can't bypass the amplifier without going up to the aerial?