RADIO NOTES
(Written for the Guardian). By “Screen Grid.”
From the Ellesmere Guardian, Volume LI, Issue 39, 19 May 1933, Page 3.
Those screws that simply won’t go into their holes on the baseboard are a source of constant irritation to the constructor. They will fall all over the place, stick under the wiring, lose themselves under components—in fact, do anything except “go home.” Several cures present themselves. Perhaps the easiest is a judicious use of soap on the end of the screwdriver. Screws and slotted terminal nuts can be dealt with easily in this way, so long as you remember to clean the scrap off afterwards. When you have a component with a thin, flat base, it is a good plan to prick holes in the baseboard first, and then hold the component a quarter of an inch or so from the baseboard. This will steady the screws until they have got a grip in the holes. A third method is to use a piece of cardboard bent at one end with a slot in it to take the screw.
Useful Dial Indicator: A very useful and effective dial indicator can be made from an old bone or whitewood knitting needle. A hole is drilled in the panel above the tuning dial or in the most suitable position, and this should be slightly smaller in diameter than the needle. A small section of the needle about the thickness of the panel is cut off and tapped into the panel hole. If preferred, an ink mark can be put on the indicator. White bone looks particularly attractive against a black or mahogany panel.
If your aerial is attached to a tree, run it through a pulley, but do not tie it. Instead, put a heavy weight on the end. You will see the logic of this when the tree sways in the wind.
Keep in mind this important fact— tuning a radio for extremely long distance needs patience and an exquisitely light wrist. Many people in search for elusive DX rotate the dial far too quickly. This applies both to broad cast and short wave. But with so much entertainment offering from Australian and New Zealand stations the writer, for one, does not do much in the way of looking for foreigners.
Incidentally, many enthusiasts are commenting on the splendid reception we have had lately. At night the air is full of “the good stuff.”
Looking back over the years— since 1919 —the writer has found that every old enthusiast’s evolution has been the same. First, a glimpse of a crystal set which in 1919 seldom worked, then a crystal set of one’s very own. Then a one-valve squealer, followed by a two or three of the same evil kidney. Then a battery short-waver, and as a final glory, an all-electric broadcast set! Those people who buy radios today have entertainment all the time. In the very old days when we heard Australia we were proud men for weeks—even though we knew our best friends doubted our truthful tongues.
Radio waves travel at 186,000 miles per second—just a few miles per hour faster than a rumour.
You will often hear short-wave telephony stations that sound like a gurgle. You cannot make head or tail of what is being said. You needn’t blame your receiver, as the transmission is probably being inverted to keep the conversation private. With some of the radio telephony quite good entertainment can be received in listening to both parties’ conversation.
When you are doing a little experimenting you often find that you are short of a valve base. With the shops closed and being unable to borrow one, you may be compelled to drop an interesting experiment just when you are enjoying it most. Should this happen to you, remember that quite a passable temporary valve base can be made out of four very large solder lugs. The shaft of some of these lugs is rounded to close over a wire before soldering. This is the type to use. They make quite a rigid job for a temporary measure.
When you are fitting a switch into a radio circuit, see that it makes a good firm contact and that the contacts are bright and clean. Otherwise you will strike trouble.
Many people have wondered how an aeroplane can use a wireless aerial. An aeroplane aerial is on a reel, and it is lowered out by means of this reel through the floor where an aperture is built in for the purpose. At the end of the aerial is an appliance known as a fishtail, which swings the aerial clear behind the machine, and which stops it from lashing. Incidentally, on one Trans-Atlantic flight, the pilot realised his danger by the fact that the fishtail smacked the water. Owing to physical exhaustion, he had no idea he was so low.
Incidentally, the best radio traditions of the sea where the wireless operator and the captain are the last to leave are also maintained in the air. Fortunately, in percentage with the number of miles flown, the number of air accidents are very rare, and when one does happen the radio operator is on duty until the last moment. In the Dole flight to Hawaii some years ago the heroic operator tapped out the last farewell messages as the machine hurtled from a great height into the sea.
The efficiency of portable radios for emergency purposes has been proved beyond doubt in New Zealand. Readers will be interested to learn that there is a thoroughly organised body equipped to deal with any type of emergency requiring radio assistance.
Battery set owners are well advised to check over occasionally the “C” battery. When the voltage of this drops the tone falls off and there is added consumption in the “B” battery.
You may notice if you have vernier dials on your radio for some time that there is a bit of play in tuning. You may overcome this by tightening up the screws on the dial and especially the screw that contains the condenser shaft. If, however, they are the old type of vernier dial, it will pay you to fit on some of the latest types, as in addition to looking better, they work better.
Should you notice evaporation in your storage batteries, fill them just above the plates with pure distilled water. Remember that the actual chemical properties of the mixture do not evaporate, so there is no need except when the battery is being overhauled to put in new “dope.” At the same time, on no account use other than pure distilled water, as ordinary water contains a definite amount of mineral properties that are fatal to the battery. The simplest way to obtain distilled water is, of course, to buy 3d worth from your service station. If, however, you put out an earthenware basin during a good rain storm, you will be able to secure a fair amount. Use nothing but an earthenware basin, as the water if it comes in contact with any metal naturally ceases to be distilled.
