Keeping Birds Off TV Aerials

Introduction

In my previous post “Freeview Aerial Direction” you may have noticed something unusual about my Yagi TV antenna/aerial. Yes, amongst the array of directors in front of the dipole and on the reflector at the back there are some Zip Ties (Cable Ties – often used for anchoring a cable to something else). In this case their purpose is to prevent birds from landing on my aerial. The problem I have is that when they take off they tend to deposit their droppings on my solar panels and so reduce their efficiency. So this post describes a simple method of keeping birds off TV aerials.

My Method For Keeping Birds Off TV Aerials

I asked my aerial erector if he could do something about it. He told me I could pay for some specific spikes to be fitted to my aerial or he would happily attach some zip ties for no extra cost if I had them to hand. I gave him a bunch and the result is shown in the featured image. In between the directors they are fixed to square tubing so they don’t rotate under gravity to point downwards. On the reflector where some round bar is used they are left long and threaded through to stop them moving out of place. Being plastic (an electrical insulator) they have no effect on the signal.

Zip ties are commonly available in DIY and electrical stores. I used black ones because they are usually more resistant to UV (ultra-violet) light.

Addendum

It’s now April 2014 and I have to advise that a wood pigeon has been seen perched in the centre of my aerial. It neatly fitted itself between two zip ties. If I could do it again I would increase the number if zip ties and have them closer together.

Terrestrial Freeview TV Aerial Direction

Introduction

In November 2012 I had my terrestrial TV aerial relocated to another corner of my chimney stack so that it doesn’t overhang my solar panels. Birds were perching on it and making a mess on them. Consequently I needed to check my TV aerial direction to be sure it points to the transmitter.

The aerial engineer (Martin Downing) worked until it was dusk when he re-attached my aerial to the chimney stack. That left him little time to adjust my TV aerial direction. I could see from the ground that the initial direction didn’t align with the aerials of my neighbours. I checked the TV picture and on some channels I got interference on my digital Freeview signal causing blocking (corrupt squares of varying sizes) on the picture. So I asked him to rotate it until it matched the other aerials nearby. The picture has been good since.

In this article I show how terrestrial TV aerial direction is accurately set using a compass instead of measuring the signal strength.

I accept that measuring signal strength at the aerial is the best method especially when an aerial is pointing towards an obstruction such as a building or electricity pylon.

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Netricity Powerline 500M Ethernet Bridge Adapter Failed After 13 Months

Introduction

Panic set in last night when I couldn’t access the Internet. Eventually I tried my laptop after checking the lights on my Home Hub and reset it a few times. That worked O.K. and in the end I deduced my power-line network had failed. It turned out that a Netricity Powerline 500M Ethernet Bridge Adapter Failed. The one connected to the PC had green lights on it suggesting it was hunting for the other adapter. The one at the router had some red lights on it. I unplugged it and went to bed. When I got up and tried it this morning the lights on the faulty one wouldn’t light  in any colour. So that was the end of my Netricity (economically priced) power-line network. I had kept the receipt but, guess what, it was 13 months old so out of guarantee by one month, typical.

Getting A Replacement

So by 09:10 I was in the local technology store, Maplin – where I got the original from, to get a replacement. I had looked one up before I went. I settled on a Delovo “dLAN 500AVplus” having previously been happy with the 500Mbps technology of the Netricity devices. Here is the Devolo website.

Well I am happy again now and to some degree the working Netricity adapter is compatible with the Delovo adapters. However I can’t seem to control it from the Delovo Cockpit. One of the benefits of the new adapter is the mains socket reappears on the front so that it can be used for something else. The manufacturer recommends plugging the router or PC into this because they have built in a filter (HF I presume) to reduce interference.

Here is the new adapter below:

Devolo 500Mbps Powerline Adapter
Devolo 500Mbps Power-line Adapter

Should You Worry About Your Bath Overflowing?

“Me, worry about my bath overflowing? Its got an overflow pipe.”

“Oh! Has it?”

Why you DO NEED to worry about your bath overflowing?

I know someone who has had a bad experience with a bath overflowing, but it wasn’t their bath overflowing. It was in a flat two floors above. Interestingly the flat in between on the floor immediately below the bath didn’t get wet. How can that happen?

Well lets start with the overflowing bath. The person, whose bath it was, admitted it had overflowed but not very much. I suspect this means that the water did actually run over the rim of the bath. That means it rose above the bath overflow outlet (assuming there was one.) On my bath, water would start to go down the overflow pipe when it is within 8cm of the top of the bath. The top of my bath is 8cm above the bottom of the overflow. So if it is full to the point where it will overflow the rim of the bath the head of water pushing out through the overflow will be 0.08m whereas the head of water from the water level in my header tank in the loft is 2m. Alternative forms of hot water provision can be at mains pressure which usually has a lot more than 2m head. My point is that the tap’s pipe diameter and overflow pipe diameter are similar but the input pressure is a lot higher than the output pressure. Consequently baths can fill faster than they can overflow. So eventually a system with no faults may eventually overflow the rim of the bath if the taps are full on. So DON’T LEAVE BATH TAPS RUNNING WHEN YOU LEAVE THE BATHROOM. You could forget to turn them off. Continue reading “Should You Worry About Your Bath Overflowing?”

Changing A Mains Isolation Switch Neon Indicator

Intoduction

You may notice how the indicator light in your mains sockets and switches dims with time and wonder why. These lights are usually small neon bulbs which glow when a small alternating current of 1 or 2mA passes through them. These bulbs are filled with neon gas which glows red when a current passes through it. There is no filament and no heating element. Neon is an inert gas which glows with an orangey red colour in these bulbs. If the current is too high or the electrodes are made of an unsuitable metal the metal evaporates from the surface of the electrodes and condenses on the inside of the glass bulb, making it opaque, so the light output dims as the glass gets covered.

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Changing a Watch Battery

Introduction

My wife’s wrist watch stopped working the other day. Usual problem – flat battery. So I popped onto the Internet and ordered four, from JewelleryForAll on the Amazon Marketplace, @ 45p each with free p+p. They arrived on 14th Jan 2012. A little late I thought since they were ordered on 3rd Jan 2012, but never mind they were cheap enough.

The Battery I Ordered

The new watch battery came in a package like this: Packaged Cell

When extracted it looks like this on the +ve side, the side which faces up in the watch. The colour is of course silver but this image allows the engraved text to be seen: +ve side of cell

This shows the -ve side, the side which faces down in the watch: -ve side of cell
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Gyroscopes & Cameras Help Bike Riding Robots

Watch This Video of Bike Riding Robots

Watch Murata Girl and Murata Boy. They use stabilizing gyroscopes and camera technology. These are bike riding robots which perform some amazing riding skills without falling off their bikes. Murata Girl is the one on the monocycle.