Ring Automotive Air Compressor RAC900


This post is about the Ring Automotive Air Compressor RAC900 which is an excellent pump for inflating anything with a Schrader valve, (e.g. car tyres, bicycle tyres, etc.) or balls, airbeds, etc. (3 attachments are supplied). It has to be powered by a 12 volt (30 amp peak) supply such as a car battery (not provided). So to use it with a car the bonnet must be opened and the battery cover removed to expose the battery terminals for connection. I don’t think it would be safe to connect it to a cigar lighter socket. It does come with an inline 30 amp fuse.


A few weeks ago I passed a friend in the street who was inflating his car tyres on his driveway with a Ring Automotive Air Compressor RAC900. He was very eager to show me his new tyre pump which was powered from his car battery. He explained how it had the following advantages over other tyre pumps:

  • It inflated tyres very quickly.
  • It had a built-in pressure gauge.
  • It was very well-engineered.
  • It came with a long yellow curly plastic pipe to reach all tyres on a car.
  • It was very quiet compared to other 12 volt air compressors I have heard.
  • It was Made in England, Leeds in fact.

Continue reading “Ring Automotive Air Compressor RAC900”

My Casio Databank Watch is DEAD

My Old Casio Databank Watch

Casio Databank Watch

I bought this Casio Databank Watch (ABOVE or LEFT) in 1995 and although it has had several batteries and replacement straps it has lasted 18 years until this week when I noticed the digits had all gone off.

A week before I noticed it had reset to a date in 1990. I don’t know why. I altered the date and time to correct it then, but now when I take out the battery and put it back the illuminating light stays on and some peculiar digits display or I get no digits.

There is an AC (All Clear) button inside but operating it has little effect. This is something I have noticed before when I have changed the battery but I have usually got it to reset. This time it is proving really awkward and I feel it is time to change it for a new one.

This is the second model I had. The first had a real bulb in it to light it up. and was bought right back in the 1970’s and lasted until I got the second model. The second model had an electroluminescent back-light that glowed green.

When they first came out it was suggested they might not last for many years but in fact it has lasted all this time and outlasted the electronics of the watch.

Maybe it has succumbed to a Tin Whisker somewhere.

My New Casio Databank Watch

Casio Databank WatchI have now bought a replacement Casio Databank Watch (ABOVE or LEFT). This is available from: Timeshop4You.

Casio Databank Watch
Casio DBC-3

These watches are available in slightly different models and from other shops. See Google’s list here.

So far I am happy with it although it has an amber coloured LED back-light. This emanates from the bottom left corner. It’s reminiscent of the old pea grain filament bulb that I had in my very first Databank watch.

The electroluminescent type in the second model gave a very even green glow which I preferred


Tin Whiskers in a Wireless Thermostat Receiver

Tin Whiskers are a crystalline growth made of the element tin.

Tin whiskers often form on lead free solder used to fix components to circuit boards since lead was banned.

They are in the form of a very thin straight hair with one end attached to the tin from which they are formed. In my case they have grown on a piece of tin plated steel used to screen electronic components which are part of a central heating wireless thermostat radio receiver. This receiver has developed an intermittent problem and doesn’t switch on my central heating when it should. I suspect there is an electrical fault which may be caused by a tin whisker growing inside the component screening box until it touched some electrical connection.

Since I have not completely dismantled the item to find out for sure I don’t know if that is correct but as you can see from the pictures the Tin Whiskers that I have found on the outside of the screening box (see featured image) are up to 2mm long. Although I already knew about Tin Whiskers these are the first I have seen in 50 years of handling electrical or electronic devices. I have used a USB connected microscope to photograph them but I have had a lot of difficulty. They are so thin they are hardly visible with a watchmakers eyeglass with 10x magnification. Continue reading “Tin Whiskers in a Wireless Thermostat Receiver”

Keeping Birds Off TV Aerials


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.


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


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.

Continue reading “Terrestrial Freeview TV Aerial Direction”

Netricity Powerline 500M Ethernet Bridge Adapter Failed After 13 Months


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 turned full on. So DON’T LEAVE BATH TAPS RUNNING WHEN YOU LEAVE THE BATHROOM. You may be distracted and forget about them. Continue reading “Should You Worry About Your Bath Overflowing?”