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 the inland waterways. 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.
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.
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.