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| Model 89A Equasonne | ||||||||||||
| Download schematics for the 89A model. Selector RF Amplifier Power converter Speaker Tubes Service Notes (for related 931 model) |
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| The model 89A (manufactured 19??) uses the same RF amplifier unit and selector unit as the 930, but differs in its power converter. The model 89A converter incorporates a pair of 281 half wave rectifier tubes rather than a single 280 full wave rectifier tube. The 89A differs from the Model 89, in that it included an electrodynamic speaker. The Model 89 came with a speaker jack for an external speaker. The cabinet very closely resembles the more common 930 and 931, but unlike these other models where the chassis is accesed through the back, the 89A has a hinged top for easier access to the chassis. To the best of my knowledge there was no DC version of the 89A. |
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| The restored and reassembled chassis of my 930 Equasonne. This chassis is very similar to the 89A. The long black box at the back is the power converter unit, which also contains the power output tubes. At the front left is the selector unit with the 4 ganged tuning condensors, 2 of which are visible under the upper shielding. The rotating tuning drum with the dial scale is part of this unit. At the front right is the RF amplifier unit. The lid (with 8 holes) on this unit is removable to enable access to the tubes. It must be left in place during operation. | ||||||||||||
