Tone Burst Generator

Stanley Kelly designed and manufactured a Tone Burst Generator in 1969.

The generator acts as a synchronised switch inserted between a source of audio sinewaves and an audio amplifier or other equipment.             `

The Tone Burst Generator circuit consists of a binary counter operating a gate, in which the ON and OFF periods of the gate may be independently variable, the periods being powers of two. Provision is made to vary the phase of the onset and cessation of each tone burst, over a range of approximately ±45°. In order to test the overload recovery time of amplifiers, as required by I.E.C. regulations, the level in the OFF position can be varied.

The maximum ratio of ON and OFF levels is on the order of 40 dB. The operating frequency is from DC to approximately 40 kHz.

Specifications

• Frequency range: 1 Hz to 20 kHz
• Signal starting and stopping phase:  can be varied ± 30° approx.
• Pedestal output:  +5 Volts.
• Synchronising pulse: +5 Volts 10 µsecs.
• Counts: On and Off 2, 4, 8, 16, 32, 64, 128 cycles

In questo link sono elencati 7 modelli, di cui 7 con immagini e 1 con schemi.
Elenco delle radio e altri apparecchi della Kelly Acoustics Ltd.; Enfield