There is a wide variety of aerials to choose from for youR narrowboat. Signal boosters and signal finders are also available if you struggle to find that crystal clear TV picture whilst on-board your narrow boat.
Aerials… Radio Signals
Firstly we should have a basic understanding of how radio and television transmissions actually work. Think of the signals we receive on our sets as being waves. The length of VHF and TV (UHF in the UK) waves is only a few metres.
VHF have longer waves and travel a greater distance than UHF (medium frequency waves are longer still) and that is why we can often receive radio where we can’t get a TV signal. UHF waves however have a higher energy over that shorter distance.
These waves cannot bend around corners and nor can they travel through dense material, such as steel, very easily.
Due to the nature of our inland waterway system, we find the canals following contours in the landscape and often alongside low lying, and relatively flat, river systems, hence finding a clear signal can be challenging on a narrow boat.
Transmitters and booster stations are in fixed locations, designed to supply a generally good signal to populated areas and often the canals and rivers meander gently through rural and relatively unpopulated areas.
Thus we can see that narrow boaters immediately have issues regarding reception that are not normally experienced by home-owners.
There are solutions. The ultimate is to install the latest in high speed internet and stream TV and radio via this medium. More on that below, but for most of us the requirement is simply to catch up with the news or watch the odd soap and that means installing an aerial that is compact in design, can be demounted easily and collects the best signals.
As we have seen, radio/TV waves don’t cope very well with objects in the way. The best signals are obtained when we have what is known as “line of sight” to the transmitter.
There are 2,023 TV, radio and DAB transmitters in the UK serving the fixed population and we are beholden to these for our signals on narrowboats too. How do we know if we have line of sight? There are small pocket sized devices available for less than £20 called TV signal finders. These plug in line to the aerial and when the aerial is “twiddled” around 360’ they indicate the direction of the strongest signal. More often than not the modern Free-view digital TV has built in signal meters when tuning channels, so it can be just as easy to use this if you have a helper to twiddle the aerial.
Don’t be confused by those shouts of “left a bit, back, hold it, little bit more” that can be heard early evening along the tow paths of the UK. It’s just TV tuners doing their thing on their narrow boats!
That’s all well and good but what type of aerial should we be using? The experts only recommend one type for mobile reception and that is known as the log-periodic aerial. Recommended due to their compact design, robust construction and ability to be demounted and stored relatively easily, they come in various designs and sizes.
A common and effective example are units that look like the bill of a saw fish! Designed for caravan use, they lend themselves well to the touring narrowboat and so long as they are pointed in the general direction of the transmitter work very well on our digital network. As they are designed for caravans and motorhomes they are available with modular accessories such as mounting brackets and extension poles.
The use of satellite grade co-axial cable in preference to the common low loss co-ax will also significantly improve TV reception, as will the use of quality connectors.
When mooring up in urban areas, expect a poorer signal. Often the canal is bordered by tall buildings or is set low along a river valley and even the use of 50 feet of pole (we’ve seen it)! won’t improve reception. Look at the direction that aerials point in on surrounding buildings for a good general idea of where to start pointing yours and if all else fails get the scrabble out or go to the pub.
Not what you're looking for? Try some other items within this chapter...