Dating guitar amp transformers how to stop ie from updating webpages
The transformer does, however, have a primary inductance, which has a direct effect on the low frequency response of the transformer.
The -3d B low frequency cutoff point can be determined by the following formula: Unfortunately, when you increase the number of turns, you also increase the capacitance and leakage inductance, which then limits the high frequency performance.
It simply reflects the impedance load on the secondary back to the primary.
A transformer has a turns ratio which can be measured by putting an small AC voltage across the primary and measuring the resulting secondary voltage.
The main parameters are: (a) the reflected primary impedance for a given secondary load impedance, which must match the needs of the particular tube being used, (b) the primary inductance, which determines the low frequency response, (c) the primary leakage inductance and capacitance, which determines the high frequency response, (d) the power handling capability, which determines the necessary core size and wire size, and (e) the mechanical details, such as the mounting style (upright "X" mount, laydown "Z" mount, etc.), the lead color and length, the use of end bells, the finish, shielding, etc.
An output transformer has no impedance by itself (ignoring primary inductance/resistance for the moment, which is a different subject).
Date Code: Wide panel, narrow panel, brown, blonde, and black face amps have a date code hand-stamped on the tube chart. The first letter translates to the year and the second to the month. Example: FG=July 1956, QA=January 1967, and a reissue CG=July 1992 EIA Source-Date Codes: Electronic components such as transformers, potentiometers, speakers, and some capacitors are often stampted with a date code indicating who manufactured them and when.Large leakage inductances can cause "ringing" at sharp transitions, such as a square wave generated by an amplifier driven into clipping.The two things that determine the power handling capability of the transformer are the core size and the gauge of wire used to wind the transformer.The code follows the format: XXXYY ZZ where: XXX = a two or three (possibly four on newer amps) digit number indicating the manufacturer.(see chart below) YY = is a one or two digit code indicating the year.
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The resulting voltage ratio is the turns ratio (you can also put a small voltage across the secondary and measure the resulting primary voltage, which is usually easier, because the voltage is higher and there is not much secondary resistance to introduce measurement errors - but watch out for high voltages on the primary if the turns ratio is large! If you put 1VAC across the secondary, and measure 20VAC across the primary, you have a turns ratio of 20:1, which corresponds to an impedance ratio of 400:1.