set of 3 vintage NOS vox intercoms [KAPO WI-353A] with fm signal on mains, very noisy hum in speakers when receiving. 100hz? psu filter caps, on all 3? no motors/microwaves active in house, all same phase, call tone same as noise. call tone seems low hz, impure sound. utterly drowns voice.
instructions are set each one on its own channel, to call: select channel of called unit. i have all 3 on same channel in 3 rooms, not sensitive enough for audio feedback.
edit #1
several caps have leaked in one unit. expect others likewise. what's good to wash the mobo with, and preserve text?
instructions are set each one on its own channel, to call: select channel of called unit. i have all 3 on same channel in 3 rooms, not sensitive enough for audio feedback.
edit #1
several caps have leaked in one unit. expect others likewise. what's good to wash the mobo with, and preserve text?
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