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Here's a nice piece of aviation artwork which you might enjoy. Click on the thumbnail for a larger view. If you would like to use this as a eurofighter2.jpg (93935 bytes) background picture on your desktop, then right-click on the large picture and choose Set as Wallpaper from the drop-down menu that appears. It will then automatically be saved as a file named Internet Explorer Wallpaper.bmp in your Windows folder and come up on your desktop. This procedure applies to Internet Explorer 5 and Windows 98, and I guess there is a similar option available in other browsers. If you already have a background image previously saved from the web in this way and do not want to lose it, then before you save this picture, go into your Windows folder, right-click on the file called 'Internet Explorer Wallpaper.bmp', choose rename from the drop-down list, then type a suitable new name for your existing picture file - make sure you add the file extension .bmp - and press return

After you've set the new picture as a wallpaper image, it's not a bad idea to rename this new file immediately as well, then you're ready to save any other pictures you fancy for your wallpaper collection. If you go into Control Panel from your desktop (Start/Settings/Control Panel) and choose Display, the re-named files will also appear amongst your list of available wallpapers on the Background tab of the Display  Properties dialog box.

about the picture . . .

The picture is a painting by Wilfred Hardy, GAvA, entitled 21st Century Team. It depicts a Eurofighter FGA1 in the colours of No 74 Squadron operating with an E-3D Sentry AEW1 of No 8 Squadron. As also stated on the home page, it is reproduced by kind permission of The Royal Air Force Benevolent Fund Enterprises and comes from the cover of their book Brace by Wire to Fly-by-Wire.

 

clear decal sheets

On ModelFlight #10, I referred to some impressive decals I had seen on a static model which had been produced on a PC, printed on ordinary paper and then photocopied on to clear decal sheets that had been purchased from Hannants. This UK company specialises in the supply of decals for the plastic modeller, and looking at their web-based catalogue I found Xtradecal Clear Decal sheets, A4 size, 3.25 (EU) or 2.77 (Export). http://www.hannants.co.uk 

 

ON BOARD NICAD MONITORS REPRODUCED BY KIND PERMISSION OF MACGREGOR INDUSTRIES LTD FROM THEIR 'MODELLERS GUIDE 2000'
The majority of unexplained failures of radio systems are caused by receiver battery supply problems. Most of these failures can be avoided if an on-board battery monitor such as the Cyclops Tri-Colour Rx Monitor, obtainable from your model shop under part numbers FDL006-009, is used in the model. The monitor will give an early warning of all of the problems mentioned below. We strongly recommend that you use this monitor.

The 'Cyclops' comes in straight, right-angle and 6V types

Reverse charge cell failure
NiCad battery cells are fairly robust and while they will stand quite a lot of abuse, they can be very rapidly destroyed by reverse charging. Cells damaged by reverse charge do not always fail immediately and it may take five or six charge/discharge cycles before the cell finally fails. Apart from connecting a charger with a reversed polarity, there are other ways in which battery cells can be reverse charged.

Battery discharge below 4V
When NiCad cells are connected in series, such as in a receiver battery pack, the individual cells in the pack need to have more or less the same capacity so that they all discharge at the same rate. Inevitably, the match is never perfect and if discharge is carried on too long, one of the cells will become discharged to zero volts. During any further discharge, the remaining cells will force electricity through the flat cell and reverse charge it. Normally it is considered safe to gently discharge a four-cell NiCad pack to 4 volts since at that level no individual cell is likely to be completely discharged.

JR's NEB480 monitor doubles as a lost model alarm

Excessive current from a low capacity battery
If powerful or numerous servos are used, the instantaneous current from the receiver NiCad can be many amperes. All batteries have an internal resistance that causes the terminal voltage to fall when heavy currents are drawn. NiCad cells have a

relatively low internal resistance but at the current levels drawn by the more powerful of today's servos, with a partly discharged battery, the voltage drop caused by the internal resistance can actually be greater than the cell voltage and this can cause an effective reverse charge.

Black Wire Corrosion
The black corrosion of connecting wires is caused by the corrosive gases given off by NiCad cells when they are overcharged. Initially, the corrosion of the wires is not important in itself and the problem arises from the accompanying corrosion of the connector pins and the switch harness switch contacts. The corrosion causes a high resistance contact that prevents the passage of the electricity to the receiver. When this corrosion is present, it can lead to very intermittent operation with the system working after the connections are moved, say when checking, and then failing after a few flights as the corrosion builds up again.

 

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