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The big problem with a directional aerial over an Omni is it usually requires quite a bit more effort to get a TV picture. The thing is that the end result is nearly always better, as with so much of life, minimum effort = minimum result (and minimum satisfaction......).
So how much difference was there between the Omni aerial and the DM Log ?
I compared the signals on analogue and digital at two different locations and at different times of the day, on all tests the Log outperformed the Omni, as expected.
Although analogue is no longer available at most locations, it actually makes a better test of aerial performance because of the way the picture degrades compared to a digital signal.
Below is typical result for a reasonable signal area on analogue transmissions, this was
off Moel Y Parc transmitter. Further down is a test in a poor signal area.
Channel
BBC1
BBC2
ITV
C4 / S4C
Omni directional TV aerial
A bit grainy (worse than the Log)
A bit grainy (worse than the Log)
Grainy, fairly bad patterning and ghosting, interference lines on LHS
A bit grainy (worse than the Log)
DM Log Periodic TV aerial
Slightly grainy
Slightly grainy
Almost perfect picture ! ? !
Slightly grainy
Note that to a TV engineer there is no such thing as a perfect picture, esp on an LCD TV...
It must be admitted that to get such good pictures off an aerial (any aerial....) mounted on the roof of a canal boat, it must have been a pretty good signal area. I wouldn`t expect this to be the case at most sites. However this throws into sharp focus how poor the Omni
was, by producing such a poor ITV. I was actually quite surprised and had to keep
swapping between the two aerials to confirm that this was in fact the case.
A more rigorous test was on the digital channels in the morning mist. The Log picked up all the Freeview programmes (that I could be bothered to check) with no problems, though
it must be admitted that all digital channels can block / freeze sporadically, no matter how good the signal. That`s due to skimping (by the broadcasters) on the error correction data,
i.e. trying to cram too many channels into the available bandwidth, see digital negatives.
The Omni failed to pick up half of the digital channels or was blocking in an annoying fashion, I wouldn`t have put up with it had I actually wanted to watch the programme...
That said, it performed significantly better than this the previous night in the different
weather conditions prevailing at the time. Then it was picking up most (but not all) of the channels OK, though the signal levels / quality were about 40% lower than with the Log.
Not that I would fully trust those figures anyway, how can they be that accurate when a digital meter costs £400 plus, and the average set top box costs £25 !
We also spent a night moored up at the foot of the Bosley locks and I automatically went onto Winter Hill transmitter (to the NNW) as every one else was on it !
I subsequently discovered that Moel Y Parc transmitter (to the West) produced better results, but some examples of the pictures off Winter Hill are shown below to illustrate what one can expect to receive in a poor signal area.
Above we have BBC1 on the left and the text off ITV (i.e. none) on the right from an Omni,
and below we have the same off a DM Log (analogue is a good indication of signal quality).
Caravan / Boat Aerial Pole Installations
It`s all very well having your aerial(s) and knowing how to get the best of them, but how do you install the pole that it`ll mount on ?
Permanent installations require a bit of thought and are outside the scope of this article but there`s a picture below left of a neat method of attaching the pole to a canal boat.
Incidentally, you`re probably better not choosing white cable. It may look nice when brand
new, but it`ll start showing up the dirt and then you`ll wish you`d gone for black cable !
The above permanent install is nice and neat, though I can`t say I`m impressed by his (or her) choice of crappy Contract aerial though, especially a gold one !
Now this is a good idea, you can mount the aerial in the highest spot available without drilling into your pride and joy ! I`d have
thought a slightly stronger mount would be better though, e.g one of our straight loft kits.
Maximising Your TV Picture Quality on a Boat / Caravan
The first thing to do if you want to maximise your picture quality from your TV aerial is
to avoid using an Omni directional antenna ! Well, sort of, explanations below......
As mentioned above in my opinion, the best aerial for a caravan or canal boat is a DM Log Periodic and that is the one we use when we hire a boat.
As we have seen there are three variables to be overcome if one is to get the best
possible picture and, apart from local knowledge*, there are two ways of achieving this.
The first involves research, knowing where all the transmitters are, their frequencies and what polarity they are. All this information is readily available but requires collating and remembering, or filing somewhere.....
For locations try our Transmitter Maps or the Digital Transmitter map or Ofcom Maps or MB21`s map page or BBC maps. For frequencies/ polarities try the last two.
Always bear in mind the over riding importance of “Line Of Sight” to the transmitter.
Even with all this info, unless it`s obvious which is the best transmitter to go for, it may well require a bit of effort and time when you actually moor up (or park up your caravan) to ensure that you really are getting the best possible signal. It is quite a satisfying achievement though !
There is another way of maximising you signal quality which avoids most of the above complication. I may not rate Omni aerials for actual reception, but they are bleedin` handy when it comes to finding the best transmitter to use your other aerial on !
How`s that then ?
Right, you moor up. You plug your Omni directional aerial in to you TV and scan right through the band, either manually or on “auto setup”. If by sheer good luck you get a picture you`re happy with, you can just stick with the Omni for your nights viewing.
If you aren`t happy with the picture, select the channel with the best signal that the Omni has just found, then plug a decent aerial in, e.g. our DM Log. Now peak it up (direction and polarity wise) on that channel. Lastly, if necessary, tune all the other stations in.
Done.
It may, or may not, be perfect, but it`s probably as good as you can get !
A cheaper, but less accurate, method of finding the strongest signal is to use one of those basic signal strength meters. Ironically the fact that a professional installer would laugh at one of those means that it`s actually very handy for finding the strongest source of TV signal, regardless of frequency. What I mean by that is using a more sophisticated type of meter (or indeed the picture on your TV) is a far more sensitive guide to the best alignment for your aerial, but you`ve got to have it tuned in to the right frequency for it to do so !
Since you don`t need to “tune in” those cheap type signal strength meters you eliminate
one of the three variables though don`t forget you still need to check which polarisation is required. So to be sure you`ve covered that particular variable you may have to go through the whole signal finding process twice, once with your aerial horizontally polarised, and again with your aerial vertically polarised.
Finally the strongest signal may not be the best quality and those cheap meters only
check for signal strength, your TV picture shows up both signal quality and signal strength !
* Having said all of the above, don`t forget the obvious, which way are the other aerials facing/polarised ? This is likely to be more accurate for the houses (as opposed to other boats or caravans) as they were probably put up by an installer with local knowledge.
Worked Example of Using an Omni to Maximise Picture Quality
As mentioned above, we spent the first night at the foot of Bosley Locks, 4m NE of Congleton. All of the other boats seemed to be on Winter Hill with their aerials pointing
NNW. Since there looked to be a reasonably clear “line of sight” in this direction I went
with it and it worked reasonably on the Log Periodic. The following morning I thought I`d experiment with the Omni and got the TV to do a search with it connected. Much to my surprise it was picking up a reasonable BBC1 on CH 52 and BBC2 on CH 45. Now I`d done
a bit of research on all the likely transmitters in this part of the world, but none had those programmes on those channels. I was intrigued. Referring to my trusty little BBC/ITC booklet “Television Transmitting Stations” (they don`t do it any more, you`ve got to print reams of A4 off the websites, such is “progress” ) I realised it must be Moel Y Parc !
I cranked the Log over to the West (Moel is the same polarity) and connected it up,
result, almost perfect pictures.
Apart from proving the usefulness of an Omni as a transmitter finder, it also underlined yet again how important “line of sight” is. Remember that Winter Hill was 34 miles away and kicks out 500kW (analogue), Moel Y Parc was 48 miles and only transmits at 100kW.
Gordon Bennet, an Omni TV aerial is smarter than I am, not good for the ego....
NOTE ! Most of the tests on this page are on analogue transmissions but that is because analogue signals show up small differences in signal strength/quality better than digital signals so the tests are actually more meaningful than those on digital transmissions.
Below is an extract from our transmitter map showing Bosley, Moel Y Parc & Winter Hill.
There are some other smaller repeater transmitters in the same area (Over Biddulph, Congleton, Langley and Macclesfield) which can be seen on the full size version of the
aforementioned map, details of the latter repeaters are (for analogue) on the relevant BBC page, or for digital see Ofcom pre DSO / post DSO or Digital UK (use the drop down menu to change the region).
Site
Ely (Nth of)
Stretham
St Neots
“Set Top” TV aerial (on the roof)
CHs 1 to 4 C5
Poor Virtually Nothing
Reasonable Poor
Very Good Reasonable
DM Log Periodic TV aerial
CHs 1 to 4 C5
Good Poor (but there ! )
Nearly Perfect Good
Nearly Perfect Nearly Perfect
In May 2009 we hired a cruiser on the River Great Ouse from Ely, which was more scenic
than you`d think by the way, though the locks were busy on the Bank Holiday Monday !
Anyway the boat came with a set top type aerial but a reasonably good one, a small Log
Periodic in fact. I took the opportunity to compare it to my DM Log and the results are
summarised in the table below. I`ve split the results into CHs 1 to 4 and C5 because the latter is low power and restricted in its radiation pattern, therefore receiving it requires a lot more from the aerial. I put the set top on the roof (when comparing them) and it worked
reasonably at most site because, let`s face it, it`s pretty flat and not that far from Sandy
transmitter ! In fact when we moored up at St Neots we could see the it, loud and proud on
the horizon. Even the set top (including when actually on the set top ! ) gave a very good
picture, thus explaining why some people think their Omnis are great. It`s all about signal
strength, even an Omni inside the boat would have given a good picture there....
More problematic was when we were North of Ely (and in Cambridge) though Stretham was
about mid way between the two, signal wise.
If you haven`t got a gang plank to
mount your aerial on try something like
this. It`s one of our straight loft kits
mounted on a 20" x 35" piece of 18mm plywood. I tried it when we were on the River Great Ouse and it worked fine.
It was stable enough to not blow over despite the wind requiring us to swing round on the bow then reverse off the moorings, more than once....
Make sure the feet on the corners are
“grippy” type rubber, plastic ones would
be more likely to just slide in any wind.
Use roofing bolts to attach the loft kit to the board, because their low profile heads won`t stand too proud below the board and touch the boat`s roof.
Storage tip, removing the pole from the mounting (c/w aerial) takes up far less space on the
boat (and ensures the aerial doesn`t get knocked off when going through a guillotine lock).
The BBC1 picture off the DM Log is not as good as it looks in the photo, it was a bit grainy, but it was obviously far better than off the Omni.
Similarly there are a few glitches on the ITV text, but again, it`s a different ball game
to the Omni`s non existent teletext reception.
The site was the foot of Bosley Locks and the transmitter was Winter Hill.
Note the weather, not that pleasant for going through 12 locks.....
Because the cable runs on boats/caravans are usually pretty short cable quality is not quite as important as it is with aerial installs on houses, but since the price difference is so small anyway it really is a false economy to use cheap crappy cable. “Low Loss” coaxial cable is not recommended, I`d always use decent quality satellite grade lead. It`s not so much for the difference in signal loss (which would be relatively small on the short runs), it`s more for the suppression of impulse noise which can be very annoying with digital pictures.
Finally when it comes to cable colour it is often tempting to go for white but remember that
it soon gets dirty, so I`d go for black myself !
There are many great mysteries in this world of ours, like the Mary Celeste, and why some lazy ignorant drivers put all that effort into winding down their window and throwing their fag end out
of it, when it`d actually require less effort to put it in the ashtray........
But along with these imponderables must rank why boaters or caravanners use Bacofoil X Beam type aerials like the ones in the above pictures. You see loads in use, in fact a large percentage
of the boats I see around seem to have them, but X Beam type aerials are fundamentally
unsuited to use as touring aerials. The reflectors mean they take up a lot of room, unlike a flat
Log Periodic aerial, and the “Xs” are hardly space saving either. Furthermore the X type directors are often a weak point on even the best of the X beams. But these Bacofoils (usually marketed as SLX, Philex or Labgear) must be the flimsiest aerials ever sold, in fact I`d say they`re only really suitable for use in lofts where there`s no wind, no birds and, hopefully, only small spiders....... When one remembers that touring aerials are usually put up and down every few days, and bashed about generally, the use of Bacofoils becomes even harder to understand.
Maybe the Bacofoil(s) are also used for the Sunday roast ? (think about it, I didn`t get it at first)
An alternative method of temporarily attaching an aerial to a (canal) boat is shown above.
This install involves lashing a “caravan” pole to the tiller with insulation tape. If you use decent quality tape and stretch it tight it works fine, but you do need to tie off the tiller so it doesn`t move and realign your aerial !
When you hand the boat back you just cut the tape off, no damage whatsoever. Whilst
cruising you can detach the top section or two (picture above left) and just clip
it back on when you moor up. The picture below right is a DM log Periodic (vertically
polarised ! ) on Skipton transmitter, with a perfect picture incidentally. We don`t
actually watch that much TV whilst boating (that`s hardly the reason one spends all
that dosh on a narrowboat is it ! ) but there are certain programmes -
Incidentally I`ve also seen tillers used for attaching other things, e.g. a clothes drier !
Caravan / Boat aerial pole clamp
This is quite a neat way to attach an aerial pole to a caravan or boat. The clamps can even be stuck on using adhesive pads which is good for those who don`t want to drill into their pride and joy, though it must be admitted that bolting, screwing or riveting the bracket(s) on would be rather stronger.The use of one, two or three clamps obviously increases the strength of the installation.
The capacity of the clamp is 25mm / 1” and they are a good complement to the 4 piece caravan pole.
Some people find wrapping tape round the pole, where it is actually clamped, helps hold it more firmly when there is a strong wind about trying to realign your aerial.
Tony Brooks of TB Training sent in this picture of his aerial pole mounting and very neat it is to.
The pole is actually held vertical by a cord running from the top
of the pole down to the front of the boat.
Unfortunately most narrow boats don`t
have a cratch board fitted but the general idea of the install
could be applied to mountings in other locations.
A couple of contrasting contraptions.
The one on the left is neat and strong
and it`s a reminder that simple U bolts
or V bolts can sometimes suffice.
Not so sure about the one on the right.
It may not involve drilling into the boat but
it looks a bit of a mess and has one other drawback which is not immediately evident.
Any idea ?
The wooden clothes peg will eventually rot.
Bet you didn`t think of that did you ?
Lateral thinking.
That`s what won us the war* ......
Incidentally that “pole” looks suspiciously
like part of an aerial cradle to me.
The Through Bracket on the right is a neat and quite strong, for a short pole anyway. It is equally suitable for use with the “caravan” pole (9ft 4in) at least if clamped fairly near the aerial.
These clamps only take a 1” pole, such as the aforementioned
caravan pole, or we also stock a
3ft x 1” pole specially for it.
A refinement on the use of a loft kit is to replace the nuts with wing nuts, this makes it much more convenient to dismantle your aerial from its mounting without having to drag out a spanner.
But we all know cheap wing nuts are prone to stripping so use decent ones ! These die cast M6 wing nuts also enable the use of a spanner to increase the torque if so desired.
nuts in
use on an
aerial mounting
We are more than willing to give advice to those actually purchasing from us.
Could those only seeking information please just find the answer somewhere on this site,
or ring an aerial installer local to them, or call the reception advice phone numbers.
TV Aerials For Boats and Caravans
Subjects are listed on this page in the following order :
The particular problems of Boat / Caravan TV reception
Aerial recommendations for Boat / Caravan TV reception (including Cable)
Maximising your TV picture quality on a Boat / Caravan (including a worked example)
How high to mount your aerial.......
Mounting Aerials : On Boats On Caravans
The fact a large aerial is out of the question is probably a blessing in disguise, because it
is highly doubtful that the mounting for it (on a boat or caravan) would be strong enough to withstand a strong wind anyway ! On the subject of bracketry and poles, that`s another problem, because aerials should be mounted as high as possible (particularly in poor reception locations) and it`s doubtful that the average boat owner / caravan owner wants a 20ft mast bolted to the side of their pride and joy. That said, a lot have satellite dishes, and they`re hardly aesthetically pleasing either, especially on a canal boat......
Actually all of the above is only the start of it, the biggest problem is that getting the best signal involves juggling with not one, not two, but three variables :
1 The direction of the transmitter is the most obvious variable, your aerial must be
pointing at it (unless you`re right next to a main transmitter ! ) or your picture will be poor.
2 The tuning of the transmitter(s) which you`re trying to receive. Even if you`re right next
to Emley Moor your screen will be just a snowstorm if your set is not tuned into it !
3 The third variable is often overlooked, and that is the polarity of the transmitter(s).
Get the wrong polarity and you could be losing up to 90% (or more) of your signal.
See Maximising Picture Quality
Aerial Recommendations for Boat / Caravan TV reception
It is possible to eliminate two of the variables mentioned above, namely direction
and polarity considerations, by using an omnidirectional or “Omni” aerial. The problem
with this strategy is that (apart from in strong signal areas), how can I put this,
Omni`s are crap. The gain of an Omni is negative. An Omni FM aerial`s gain is -
Furthermore an Omni`s beam width (to eliminate unwanted signals), is, well, 360° !
If you get a good picture off an Omni TV aerial it`s because you`re in a good signal area,
I reckon that a coat hanger* would work just as well, in fact it may well work better.
The fact is that in a poor signal area an Omni aerial is about as much use
as an Italian Kamikaze squadron.
* A metal one obviously !
I have always said that Omni directional TV aerials can`t be any good, but that was a theoretical position until we hired a boat which came with one fitted. Much to the annoyance of my wife, I was able to experiment as to the differences between an Omni and the aerial I recommend for touring, a DM Log Periodic. I`m a fan of Log Periodic aerials and this model is well suited to the role of touring. It`s reasonably compact (3ft 6in long) bearing in mind that you never get anything for nothing, remember, all things being equal, a smaller aerial will give you less gain / signal. As of August 2010 we also stock a shorter version of this aerial, the DM18 Log, so called because it only has 18 elements compared to the 26 of the “standard” DM Log. The DM18 is only 2ft 6in long but, unfortunately, you will obviously pay for that with slightly less gain, about 1 to 2dB less, so unless you`re certain you need a shorter aerial I`d go for the standard version.
The DM Log is pretty strongly made and because it`s nearly all metal in construction it`s eminently fixable if it gets damaged, as any touring aerial is bound to be...... Furthermore, Log aerials are flat, thus making storage much easier and lowering the risk of the antenna being damaged.
At a conservative estimate the gain* of the DM Log would be about 6 to 7 dB and since we use it as a control aerial for all our antenna testing its relative gain to all our other aerials can be seen on the relevant graphs. Now it must be admitted that 7 dBd is not "high gain", but since all high gain aerials are large, and as such are unsuitable for boats or caravans anyway, I wouldn`t worry about that too much, particularly as we`ve just discovered that an Omni has minus 3dB of gain. So, compared with an Omni, a DM is high gain !
On the subject of which, we sometimes get asked if a Log40 would be a better choice (for a boat/caravan aerial) than a DM Log because its gain is a bit higher. Well yes and no would be my answer. You do get a bit more signal out of a Log40, but on the other hand the DM Log is 10in shorter, it has a tilting clamp, and, most importantly, it`s more easily fixable if it gets damaged. Whilst testing an aerial I once bent some of the alloy rod type elements on it, but when I tried to straighten them some just broke off !
So, basically, I`d always recommend the DM Log, and only the DM Log.
See customer feedback using a DM Log on a canal boat.
* Take aerial manufacturers gain figures with a pinch of salt......
The DM Log can just about be seen to the left of my wife and my parents as they finish their wine outside in the dusk, the aerial is more clearly seen in the reflection on the water !
This is one of my favourite pictures and if it doesn`t put you in the mood for boating,
then nothing will......
If you`ve found this site informative and, hopefully, interesting as well,
please help us increase the number of people reading it.
I`m actually a boater not a caravanner (my parents in law are ! ) but I don`t see why the “board method” shouldn`t work on the roof of a caravan, certainly one with a flat(ish) roof.
Neat removable way of attaching an aerial pole to another vertical tube. These are particularly well suited to bolt an
aerial pole onto a caravan jockey wheel, as shown right.
It is possible to use just one “double clamp” and push the bottom end of the pole into the earth, but if parked on hard standing then you need two, as is shown in the picture.
Whilst it is preferable to support any aerial pole further up, bolting a 9ft caravan pole to the jockey wheel was actually a
bit sturdier than I expected.
The Particular Problems of Boat / Caravan TV Reception
Since any aerial used for reception on a boat or caravan is usually required to work at different locations it is a given that a wideband aerial is required, with all the inherent disadvantages that this can bring in poor signal locations, compared with a grouped aerial. Much as I dislike wideband aerials (wideband Yagis anyway) it must be admitted that the requirement for one is the least of the problems for a boater, or caravanner. Many sites are in poor locations, especially for boaters as waterways tend to be in valleys.....
See Importance of Line of Sight.
Furthermore space, for storage of the aerial, is usually at a premium on a boat or in a caravan, so an aerial of large physical size is problematic. Unfortunately, as a general rule, larger aerials give more gain (i.e. more signal) and smaller aerials give less gain. Just using an aerial amplifier to “boost” the signal from a low gain antenna is unlikely to be effective. I certainly found this to be my general experience, particularly when used with an Omni directional aerial.
Since the aerial is being put up and taken down regularly it needs to be pretty strong as well, I`ve seen some which are literally falling apart, though, somewhat surprisingly, they`d probably still give a decent picture in good reception areas.
Speaking of the latter, it is important to understand that the range of possible signal strengths available in this country is HUGE, see article on this subject.
* well that plus the Royal Navy and the English Channel......
You can use a satellite rather than an aerial to receive your signals, though you`ll usually require a separate satellite set top box in order to do so, but what are the relative merits of satellite v aerial ?
Basically it`s swings and roundabouts. There are places where a satellite will work perfectly and an aerial will only give a poor signal, but on the other hand, there are places (e.g. with trees or buildings in the way) where an aerial will work and a satellite won`t work at all.
Setting up an aerial is usually much easier than a satellite, particularly if there are any houses around, you just point your aerial in the same direction and polarity as theirs, retune your TV, and that`s it, no meter, no fine tuning the dish, nothing. As the analogue is switched off the digital signal will be greatly increased in power so less problems should be experienced finding a signal, but on the other hand the “old” analogue signal is more reliable in poor signal areas, albeit at poorer picture quality, than the digital one, so again, plusses and minuses. I accept that there are times when it`s not that simple to get a decent signal from your TV aerial (for those see the article above) but we regularly get people buying aerials because they find setting up a dish too much hassle. I personally find them too much trouble so we don`t even sell satellite stuff for boats/caravans, but that`s not saying some people won`t find it a viable alternative.
Bear in mind that satellite tuners do tend to increase the current draw from your battery, particularly if it`s a set top box in addition to the TV.
When it comes to satellites, the size of the dish has an important bearing on ease of
setting up and the reliability of the received signal. Basically a smaller dish will have a wider acceptance angle than a larger dish. This is good and bad. It`s good because it`s easier to aim it at the satellite and therefore quicker to set up. This may explain how come aerial installers use £300 meters to set up a domestic installation (and take time doing so) when some caravanners/boaters can, apparently, do it in 5 to 10 minutes with a £30 meter ! Furthermore the wider acceptance angle also means that there`s less chance of the signal going off due to movement (e.g. of a boat at its moorings), though this would not normally be a problem in a caravan, unless you`re in an earthquake zone, or your suspension is soft and there are hurricanes about, or someone you wouldn`t want sitting next to you on a plane*
is vigorously moving around round inside your caravan.
The down side of a small dish is the quality of the signal can never be as high as with a large dish, for the same reason that an Omni directional TV aerial cannot ever give as
much signal (or gain) as a directional one. Less signal from your dish means that there`s
a greater chance that bad weather will affect your reception, so, at the end of the day,
you pays your money, and you takes your choice.
* staturewise
How high to mount your aerial ? Well that`s a big question.......
Generally speaking the higher the better, at least that`s the usually case with aerials.
But not always.
In the past we`d done tests on aerial heights for installations mounted on roofs, but what about at the kind of height the average boat or caravan owner would have his antenna ?
Whilst checking up on the accuracy of testing aerials at 6ft (it is accurate by the way.....) I also compared the signal at the test site at 6ft and 12ft, which is about the sort of heights that boaters and caravanners use.
I measured the received signal off three transmitters : Emley Moor, Bilsdale & Belmont.
The transmitters were in three different directions, and there was "line of sight" to all of them.
The results are fascinating.
An increase of 4.1dB (which is signal rise off Emley Moor) for raising the aerial only 6ft is huge.
To put it into context that`s not far off the increase in signal you`d get by swapping a little 3ft 6in DM Log for a big 5ft 3in DY14WB ! Even the 2.3dB increase off Bilsdale is a significant improvement.
However.....
Off Belmont there was actually a huge 4.8dB decrease ! Why this should be when there was nothing between the aerial and the transmitter (albeit 65 miles away), well your guess is as good as mine. It`s a perfect example of RF being a black art.
Note the spread of results, the averages can give a misleading impression (as is the case so often). Some signals off Belmont wouldn`t be that much different, but one in particular was 8dB down. Now that is massive amount, but, of course, even with that reduction, the TV may still work perfectly if the signal strength was high enough, which at this location it would be.
