Common Issues With Digital TV Signals

Jan 18, 2021

Why does my Digital TV keep losing signal?

You are watching TV enjoying your programme and you notice the picture seems to freeze and a message appears in the middle of the screen saying, ‘weak or poor signal’- then it appears to right itself for a while.  Do you notice this on all channels or just on some channels? Does it do it for a while, and then everything seems fine? Then at other times it seems to play up often, like your TV is having bad day!  As experts for TV Aerials Manchester we know why this happens and more importantly how do I Fix it?

Well let’s consider some possible reasons for this phenomenon and what is the most likely culprit.  Intermittent faults are the most annoying and can sometimes be the hardest to diagnose. Especially if you are not an expert when it comes to Digital TV.  Thankfully we have sophisticated signal measuring equipment. This helps us get to the bottom of these types of problems pretty quickly. But, let me share my years of experience with you. I’ll explain why you are perhaps getting the ‘weak or poor signal’ message accompanied by freezing or pixilation from time to time.

TV signals fluctuate

TV signals from your nearest tv transmitter are not constant but fluctuate. There are usual atmospheric causes and reasons for this happening. The good news is that for most of us these do not affect our TV enjoyment one jot. Digital TV signals do have a more cliff like roll off. Compared to Analogue which is more of a gently sloping hill. Generally speaking most of us (especially those of us with Digital TV Aerials/Antennas) receive well above the acceptable safe threshold for reliable tv reception. Hence, we do not notice when the signals fluctuate as they never actually fall below that safe threshold. 

However, if you are on the edge of that safe threshold, say just before the cliffs edge, then when there is a fluctuation in the signal level you soon know about it, hence the intermittent problem of a weak or poor signal and the freezing or pixelating that goes along with it.  I suppose it’s a bit like having some missing slates and a hole in your roof, you only know about it when it rains 😉

The only way you can determine if this is the reason you are getting the ‘weak signal’ message periodically is to call a qualified Engineer to run some tests. We offer a FREE no obligation survey and quote, so if you are experiencing these issues by all means give us a call and we’ll be sure to get to the bottom of it for you.

Water ingress 

Let’s look at another common reason for why your TV might keep losing signal from time to time- water ingress. This is quite easy to spot, even for the non- Digital TV expert may be able to diagnose this one. Have you noticed that you get the ‘weak or poor signal’ message when it rains? If so, then you well may be having an issue with water ingress. How does this happen? When the TV aerial is sited on your chimney stack for example as is quite common. The TV Aerial is exposed to all the elements. Ordinarily TV Aerials/Antennas are designed for outdoor installation and are weather sealed. Yet over time a few things can happen that can compromise the sealing on your TV Aerial/Antenna. This can allow small amounts of water to ingress. Let’s consider some.

What a nice perch!  

Next time you are out and about walking around the streets in your area take a look up at the roofline of the house and see if you can spot perched happy on top of some TV Aerials/Antennas birds.  Birds love perching on top of TV Aerials, why I don’t know for sure, my guess is it’s just convenient.  However as convenient as it is for those birds to perch on top of your TV Aerial, over time this can cause problems for your TV Aerial, namely every time the bird launches itself off from the TV Aerial/Antenna the Aerial flexes considerably and over time- usually a few years, the waterproof seals that connect the coaxial cable to the TV Aerial/Antenna may start to work lose and, in some cases, come off altogether.

I have seen this so many times when inspecting a TV Aerial that is having issues.  What’s the solution? Well invariably once water has got inside the TV Aerial/Antenna, it is a new TV Aerial I am afraid.  However, if Birds are prone to Land or your TV Aerial, we have the solution when fitting your new TV Aerial, and that is bird spikes! 

Do Bird Spikes Work?

These cleverly designed spikes affix to the boom arm of your TV Aerial/Antenna and deter birds from landing and launching off your TV Aerial, thus not shortening the life of the Aerial. A TV Aerial Engineer will know if you are having an issue with birds as there are lots of tell tales signs- like bird poo and lots of it.

Adding Birds spikes to the boom arm of the TV Aerial/Antenna does not in any way impact your signal. They aren’t even visible in most cases from the ground. So, if you are having a new TV Aerial installed it certainly makes sense. Talk to your TV Aerial engineer about whether it’s worth fitting some spikes on the TV Aerial while he is up there. It doesn’t really cost much more to add them at the time of the installation. More importantly, it could extend the life of your TV Aerial.

 You have the wrong type of TV Aerial!

This is another reason why you are losing TV signal; the problem is simply that the TV Aerial you have may have been fitted prior to the Digital Switchover. Therefore, be an Analogue TV Aerial.

While an Analogue TV Aerial will receive Digital TV signals, it struggles to do so. Let me explain. Analogue TV Aerials are designed and tuned to a narrow band transmission. Simply put less information being sent over the airways. Remember when we had just the 4 TV channels?  You get the idea. Then in 1997 channel 5 was launched and we had 5 channels. At that time many with the Analogue aerials couldn’t get a reliable reception of channel 5. The picture was grainy. Hence, the TV Aerial Industry started producing ‘Wideband’ TV Aerials. These are also know at the time as ‘Channel 5 Aerials’. Soon, out came the riggers fitting these new ‘Wideband’ analogue TV Aerials capable of receiving a good picture on channel 5. 

The Launch of Freeview

Then in 2002 Freeview launched on the brand-new Digital TV platform and analogue’s days were numbered. Again, even those with the new ‘Wideband ‘TV Aerials struggled with receiving a reliable good quality reception of the new Digital Freeview service and the TV Aerial industry again started making these brand new ‘Digital TV Aerials/Antennas and again out came the riggers.

If the old analogue TV Aerial struggled receiving the one extra TV channel, channel 5, then think how much more so will an old analogue TV Aerials struggle, receiving upwards of 100 channels on the new Freeview platform?  Hence the reason why your TV may keep losing signal, is your TV Aerial may be an old analogue Aerial?

Are you in a black spot?  

This is yet another reason why you may keep losing signal. It could be that where you are is a ‘signal blackspot.’  Signal ‘blackspots’ are areas around the UK where there is simply too much distance between you and the nearest TV transmitter. Or, you live in a Hilly or mountainous part of the UK where the line of sight to the nearest TV transmitter is compromised, in either case a visit by a qualified TV Aerial Engineer will ascertain the problem and solutions. What are those solutions? Let’s discuss that in the next section.

How do I fix a bad Digital TV signal?

Again, there’s not one simple answer but let us look at a couple of problem and their fixes. Let’s say you are in a ‘Blackspot’ and you are getting the message on screen ‘Weak or poor signal’. So, you call a TV Aerial Engineer like ourselves. After carrying out a survey he informs you that your TV Aerial is not getting enough signal as you are in a ‘black spot’. While there may be nothing physically wrong with your TV Aerial, it just cannot make up for the low signal being received.

There are three solutions:  1) A High Gain Digital TV Aerial that is 50 Element or above. 2) A taller mast 12-15ft, this will also require a suitable cradle bracket for the chimney or T&K bracket if it is to be gable end mounted or 3) A masthead amplifier installed to your existing TV Aerial to help boost the level of signal received, or in extreme cases do all three, perhaps this blackspot is particularly bad!  One or all three of these should solve your poor signal issues if it’s just a matter of low signal, but what if its interference? Let’s look at that next.

Is the problem interreference? What can interfere with a Digital TV Signal?

We discussed how birds, fluctuating signal. Also, how blackspots and water can cause you to get the ‘poor or weak signal’ message. Plus, along with that the annoying freezing picture problem. Let’s consider another reason for poor signal reception- interference.

Just as you cannot see TV signals, you also cannot see interference. But you can see the effects of it- freezing picture, popping audio and the ‘weak or poor signal message’ on the TV screen. Again, if you call a qualified TV Aerial Engineer, he will be able to tell you pretty quickly. He can tell if the problem is interreference and not a dodgy TV Aerial.

How does a TV Aerial Engineer know if it is interreference?

A spectrum analyser. A spectrum analyser does exactly what it says on the tin. It analyses the entire spectrum or bandwidth not just for TV Aerial signals but also Co Channel interreference. Put simply, this is when you have competing signals on the same or close frequencies.

These can come from outside sources like overhead power lines or mobile phone masts. Interference is also found inside the home from. Thermostats in lofts (say if the TV Aerial is loft mounted) or WIFI boosters or routers. So, how do you know where the interference is coming from?  This is where a qualified Digital TV Engineer is a must. He will be able to interpret the data his Field meter gives him and know where the ‘spike’ is on the spectrum. Thus identify the culprit. A lesser qualified engineer who does not carry a Spectrum Analyser or know how to use one, simply will not be able to solve this puzzle. Believe me, sometimes it really is like trying to solve a puzzle.

The good news is, there are solutions and work arounds once the interreference is identified.

Will a signal Booster improve my Digital TV signal?

Again, this is a yes and no answer. Yes, if it is simply a matter of low signal being received say in a ‘black spot’ area, yes, a signal booster (amplifier) can help make a difference. If the problems is a Co Channel interference issue as discussed above. Then no, a booster will not improve your TV signal. Because, the booster (amplifier) will boost or amplify the interference at the same as amplifying the TV signal. Do you see the problem?

A general rule of thumb. It is better to avoid amplifiers and booster where possible. Achieving a high strength clean head end signal is always more preferable over an amplified signal, why? Because TV signal amplifiers and booster add their own interference or noise into the mix. So, if you have two TV point signals both reading a healthy 55dB at the socket? One comes clean from the TV aerial with no booster involved. The other comes via a booster or amplifier. The one direct from the TV Aerial will be a cleaner, better-quality signal, as there will be much less noise in that signal. Hence, we have always used TV Aerial signal boosters as a last resort. They can be very useful and help get you over that hump, but they are not always ideal.

How do I boost my TV signal?

Providing you have optimised the signal at the head end and done your best to get a clean strong signal. However, if you are still just below the acceptable threshold, then fit a booster or Amplifier. This can be the thing that helps getting you over the hump and a signal level that will ensure trouble free viewing.

So, you have a few choices but in the interest of keeping this simple lets look at 3 options. None of these options includes boosting the signal at the TV point, we have all seen those types of boosters in B&Q – the plug and play – stick your coaxial cable in the booster and a fly lead out to the TV- those type of boosters are simply put, a waste of time avoid them.

The Correct Way to Boost a Digital Signal

If boosting a signal always boost at the head end (closest to the TV Aerial/Antenna). So, you have 1) A MHA- masthead amplifier with variable gain 2). A set back Amp with variable gain and 3). A setback amplifier without a variable gain. What is the difference between a MHA and a setback type of amplifier? How you power them. They really do the same thing effectively. The MHA amplifiers comes as a 2-piece kit- splitter box and 12v power supply. For reasons that you can power the amplifier remotely. This is if there isn’t a power supply in the loft space where the amplifier needs to go. Or you are fitting an outdoor TV Aerial/Antenna, in which case you will need to power the MHA from inside the house. How do you set these up? Please see this video: 

When choosing between the variable gain and the non-variable gain, simply ascertain how far off the signal level is. If it’s only 10dB off your target, I suggest always use a non-variable gain type. If you are lower than that, then a variable gain MHA or set back amplifier will be needed. There are some variable amplifiers that boost the levels by +10dB and some that boost the signal by +25dB.  We always keep a selection for every eventuality. 

For help from a professional engineer contact us on the number below.


TV Aerials Manchester, 22 Lever Street, Manchester. M1 1EA Tel: 0161 883 1945