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 Pocket Transistor Radios- No Sound. & Osc. 3 tips

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Join date : 2010-11-22

Pocket Transistor Radios- No Sound. & Osc. 3 tips Empty
PostSubject: Pocket Transistor Radios- No Sound. & Osc. 3 tips   Pocket Transistor Radios- No Sound. & Osc. 3 tips Icon_minitimeMarch 21st 2019, 6:35 pm

When I first started servicing radios, longer than I care to think, I ran into a period of "Cheap imported pocket transistor radios"
 The symptom of all of them was "No Sound".
 Not one single radio had a bad speaker or output transistors.
 One had dirt on the earphone jack killing sound to the speaker.
 ALL the rest had the electrolytic cap. feeding the center terminal of the volume control open up.
 A signal tracer I designed & built made this a quick & easy diagnosis.

Hum or Oscillation in a battery radio.
Often there is an electrolytic across the battery . Sort of a "bypass cap".
 If it opens, it can cause the above problems. Unless you are aware if it, it can cause some nightmare problems in the sets.
 In addition to the above, if it turns leaky, you can drain a new battery in a few short hours.
 If the 'lytic capacitor "dead shorts" it can cause the battery to explode or cause a fire.

NOTE: This cap going bad was a common problem in remote controls.
 The usual customer complaint on this was "I just put a new battery in yesterday and it worked fine, but when I tried it this morning the remote was dead."

 Yeah, more than you ever wanted to know. 
Just wait until you burn your hand on a red hot battery...... Embarassed Shocked
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