Hammond Organ

Servicing the Hammond B-3 Type Pre-Amp

AO28 Layout AO28 Schematic General Description The AO-28 tube pre-amp is found in the Hammond B-3 as well as several other models. C-3, A-100, RT-3, D-100 etc. Designed in the fifties, this pre-amp remained in production until 1975. And, it remains fully functional and serviceable today. This discussion is designed to help owners do some […]

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Servicing the Hammond B-2/C-2 Type Pre-Amp

Table of Contents AO10 Layout AO10 Schematic General Description The AO-10 tube pre-amp is found in the Hammond B-2 as well as several other models. C-2, RT-2. Designed in the forties, this pre-amp remained in production until 1948. And, it remains fully functional and serviceable today. This discussion is designed to help owners do some

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Servicing the Hammond Tone Generator

Technical Description From Service Manual Each Hammond Organ Console has a main generator within it, and in some cases, depending on the model, a chorus generator. The main generator consist of the generator proper, a shaded pole induction motor for starting, a non-self-starting synchronous motor for driving the unit after starting, and a vibrato scanner mounted on the run

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Hammond Generator Filters

General Description From the Service Manual: As a means of eliminating any vagrant harmonics that may be present, there are filters consisting of small transformers and condensers associated with certain frequencies. The transformers have a single tapped winding, and this tap is grounded, so one side, which is connected to the corresponding magnet coil through

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Tone Wheels

General Description From Service Manual. Each tone wheel is a steel disc about two inches in diameter, accurately machined with a definite number of high and low points on it’s edge. Each high point on a tone wheel is called a tooth. the number of teeth on each of these tone wheels, in conjunction with

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Hammond Synchronous Run Motor

General Description The run motor is a non-self-starting synchronous motor. Rather than delivering a constant power, it delivers a series of pulsations, one for every half cycle. That would be two pulses per cycle and 120 pulses per second with a 60 cycle current source. RPM is 1200 for 60 cycle motors. 1500 for 50 Cycle. These motors do not usually have many

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Console Start and Run Switch Wiring

General Description From Service Manual When the organ is started, the starting switch is turned on and held for about “8” seconds while the starting motor brings the system up to speed. The “run” switch is then turned on. This switch simultaneously connects the synchronous motor and introduces a resistor in series with the starting

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