Examine for broken aerial, broken lead-in, loose connection to the set, or for any cause of a short circuit, such as other wires being across the aerial and touching it.

Weak Signals

Examine for dirty insulators, cracked insulators, dirty or loose connections, leakage of power due to rain, snow, or soot, leakage on the lead-in wire, aerial placed too low, lead-in too small in diameter.

Earth Connection. No Signals

Examine for a break, or loose connection, or broken contact with earth plate.

Weak Signal

Examine for loose or dirty connections, connection too long, or too small in diamater, or for bad connection and contact finally with the ground.

Headphones. No Signals

The quickest way to find if these are at fault is to try another pair, if such are not available then put the phones on the head, moisten a copper coin, place it in the palm of left hand, moisten the tips of finger and thumb of the left hand and with these hold one of tag ends of the headphone leads, with the right hand rub very gently the other tag end on to the surface of the copper coin which is in the palm of the left hand. A distinct rustling noise will be heard if the headphones are in good order. If no sound is heard, examine the flexible cords carefully for a break ; if such cannot be seen or found, try touching the tag ends, for an instant on to the terminals of a single dry battery. If no sound be heard, disconnect the flexible cords from each earpiece, and with two pieces of covered wire make temporary connections to the two terminals of one earpiece, touch the two ends of these wires on to the terminals of a single dry battery, a loud click should be heard, if there be no sound heard, then it will generally be found that such an earpiece has a defect in the circuit of the internal magnetising coils, probably a defective coil, and requires a new coil. Should the above, however, give a sound in the earpiece, then it will point to the fact that the flexible cord that was taken off was defective, it should be replaced with a new one, unless the break can be found and repaired. It may be found that one earpiece only is defective, in which case the flexible cord can be replaced, and the two terminals on the defective earpiece short circuited by a short length of wire, and listening be continued on one ear piece only.

Weak Signals

See that all connections are tight and clean, try an exchange with another pair, it may be that the fault is not in the headphones. If the fault is clearly in the headphones, ascertain whether both earpieces are equally loud ; if one is louder than the other, see that both caps are equally tightly screwed up ; if still one is weak, then unscrew the ebonite cap gently, lift the diaphragm carefully, examine carefully the tops of the exposed magnets for slight dirt or any foreign matter, brush any such off, replace the diaphragm and cap, if still bad try rotating the diaphragm, say through 90° and test once more. If still bad, try the effect of using thicker or thinner washers under the diaphragm. The centre of both diaphragms when tapped very lightly with a finger nail should give out the same sound ; this test must be done when each diaphragm is in its place and the cap rightly screwed up. The excellence of the working of any earpiece depends very largely upon the steel magnets in these keeping their magnetism, and if one earpiece be good and the other bad, it is easy to test whether the bad one has lost part of its magnetism, by drawing gently the diaphragm across the magnet tips, the bad one should then show much less pull than the good one, the only remedy then is a set of new magnets, or remagnetising the defective ones.

Loud Speaker. No Signal

Substitute with a pair of headphones, if these show results then try the flexible cord of the loud speaker for a broken circuit, substitute the flexible cord by two wires ; if still there is no sound then the defect will be in the loud speaker, and generally speaking it should be returned to the maker for repairs.

Weak Signals

See that all connections are tight and clean, if any adjustment be provided on the instrument for adjustment of the position of the diaphragm relative to the magnets, try the effect of moving this slowly ; if there be no improvement, then probably the magnet system is defective and it should be returned to the makers.

Crystal Sets. No Signals

Having carried out the above mentioned tests first, then examine all connections on the set, see that contact is really being made on the crystal, and that the contact spring is making contact with its holder ; make certain that the transmitting station is really working, it might be silent due to a breakdown.

Weak Signals

Probably due to a dirty or loose joint in the connections of the set, or to a bad spot being used on the crystal, or to the tuning coils being incorrectly adjusted ; any of these points can easily be checked over. Another reason may be that the transmitting station may be using less power than usual.