One of the joys of getting older is the U3A. If you have not heard of this it is a sort of co-operative organisation for interest groups. You might want to web-search for the U3A in your area to discover if there is anything of interest to you.... I have recently started a U3A Aeromodelling group in our area. But that is not the point of this message.
Yesterday at 14:00 we had a meeting, in our house, of a U3A group. It is a very small group, with only three members. Anyway, one member was late and I decided to use the time until he came to fill the bird feeders in our back yard. The bird food is stored in tubs in my aeromodelling workshop/cellar. One of the feeders was not allowing the seeds to fall properly so I decided to drill out a bit of the plastic to make it more effective. I started my small pillar drill and did the job, but as I did so a high pitched noise started. I stopped the drill, but the noise continued. At first I thought it was a smoke detector, but it was not beeping, rather it was a continuous tone.
I turned off all the mains sockets I could find but the noise continued.
This is where the ageing bit comes in. Of recent years my hearing has become a lot worse, particularly in one ear. This is not a great problem to me - although Mrs Hairy Dave says that I do not hear what she says when she is telling me to do something - but is does make it harder to detect the direction to the source of a sound. Being in an enclosed cellar, the noise was bouncing around, and although it seemed to be coming from one corner, near the drill, when you went towards that corner it seemed to be coming from somewhere else. Mrs Hairy Dave came down and tried to pinpoint it. She could do no better than me. Our missing U3A group member, Chris, had by now arrived, and he was roped into the search. We still had no success.
I had to divide my time between searching for the noise and supporting the other two group members in their tasks. (Mrs Hairy Dave and Chris are learning some computer programming. They were trying to debug a programme.) The cellar is very cluttered, and I was moving things around in order to clear the offending corner. I still could not find the source of the noise. Time went on.
Then I had an inspired thought. A neighbour has a son who was due to return from school. I asked his mother if I could borrow him, and a few minutes later he came across, and it took him less than a minute to find the source. This was 90 minutes after the noise had started.
It was an old Jump Start unit. One of Machine Mart's best - a bright red plastic box containing a lead acid battery and the circuitry to jump start a car. The case was cracked, and at some point it had fallen over and some of the acid had leaked - but it was still there in case it or its battery "came in useful".
I had no idea that it contained a sound source. I can only imagine that it is intended to indicate that the battery is flat, and that the vibration from the drill caused the low voltage sensor to trip.
I got the back off it and disconnected the battery, and the noise stopped.
Why have I written this stuff here (I can imagine you asking!)?
Well ...
1. It is related to flight - birds fly, and I was intending to feed them.
2. It is aeromodelling related in that it took place in my modelling workshop.
3. It might be useful to you if you have an unidentified noise in your cellar. Jumpstart Units can make noises.
Hairy Dave
p.s. The birds did not get their food until about 17:00.
