Glossary of Wireless Terms

Radio Record, Volume II, Issue 10, 21 September 1928, Page 31

Glossary of Wireless Terms

Irom week to week we give. here asection of the glossary of wireless terms from the "Listener’s Guide." | : |

OXIDE RECTIFIER.--Plates of metal having oxidous surfaces are clamped together and have the effect of only permitting current to flow through the system in one direction thus rectifying alternating currents, See ‘Bulb Recti-PACK.-See "Kit." PARALLEL.- Where current from 2 battery divides between two or more instruments and the whole current does not flow through each instrument in turn the connection is said to be shunt or parallel in contra-distinction to the second connection, which would be said to be in series, In the case of batteries where two or more are connected with all the positives and all the negatives joined together the connection is parallel so that the total voltage is the same as a single battery, Where the positive of each cell is joined to each negative so that 10 batteries of 2 volts each gives a total voltage of 20 volts for instance the connection is series. A series-parallel connection is one in which a combination of cells or batteries may be joined in parallel, and then such groups placed in series. On the other hand a combination of cells may be join: ed in series and such groups placed in parallel. It is to be noted that batteries joined in parallel must be of equal voltage. Semi-parallel connections of headphones or speakers may be carried out under certain circumstances,

PEAK.-A point in tuning at a given frequency where the most accurate setting, and consequently best results, are obtained. An efficient coil has a very pronounced "peak," or "optimum," effect, and the desired signals are lost within @ very few degrees of condenser setting on either side of that peak, See "Selectivity." PERIKON.-A. form of crystal detec: | tion in which contact is made between 4 two erystals, such as zincite and bornite. PLATE.-An alternative term for the anode of the valve. POSITIVE.-One of the terminals of an accumulator, battery, or cell. It is important in all cases and_ vital in some that the batteries should be correctly connected in relation to their poles, to the set; the point applies also to the ’phones. See also "Negative." POTENTIAL.-A_ relative quality; best explained by an example: thus, the positive terminal of a 6-volt accumulator has a positive potential of 6-volt (or 6v plus) relatively to the negative terminal -which is, of course, 6 volts negative (or 6y. minus) in regard to the positive terminal. Difference of potential between an electrically-charged cloud and the earth (or between two clouds) causes a lightning flash, or "spark," when the difference is sufficiently great to break down the insulating property of the air. Any difference in potential can be expressed in volts.