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 Post subject: GE Micro C-2450A questions
PostPosted: Feb Tue 18, 2020 7:07 am 
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I've been working on this little guy a little lately and have some questions, and some answers from a previous thread about this model. viewtopic.php?f=4&t=315462
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I lost the "Micro" plate somewhere along the way.
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First off, there were some unanswered questions/requests in that thread I wanted to address. I have solved the riddle of how to open up the base station, and have some photos.

The solution to the base station opening is the two small philips screws on the bottom of the case and the plastic feet they hold down. Remove the screws, loosen the plastic feet from the bottom, then slide the feet toward the back of the cabinet. They will then fall right out. This frees the inside from the cabinet. After the power cord is freed everything slides right out. No need to remove any knobs or dial cover.
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The battery (not original) fully charged measures about 3.65 volts, close to the 3.75 listed on the schematic.
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And, here are some photos of the circuit board.
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As for the radio, mine doesn't work and may be beyond my ability, as it seems to have several issues, not the least of which is corrosion from the original battery. My question right now concerns the speaker. It took me a while to realize that it isn't a PM speaker, but rather an electromagnet type. I assume that's the purpose of the center tap on the speaker terminals (the red wire).
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Here's my first question. Why does any sound coming from the speaker stop when the red wire (the apparent field coil power) is attached? The sound that does come out without the red wire is very weak. The voltage at the center tap is 3.65. The two yellow wires come from the IC audio output. I have checked the resistance of both halves of the coil and they seem good. Am I missing something as to how it works?

And finally, does anybody know where I can find the tiny screw that holds the thumb wheel on the on/off/volume control?

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 Post subject: Re: GE Micro C-2450A questions
PostPosted: Feb Tue 18, 2020 7:23 am 
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The normal first order of business in most any radio from half century or more ago, is to replace the Electrolytic's. Yours only seems to have two, and the PCB is relatively uncrowded on the solder side.

That might get it singing, and cure the lead going to the center lug of the speaker from killing the audio.

AFA the tiny screw, I have a metal hardware junkbox with all manner of smaller screws, bolts, springs, connectors, etc., which is sorta what you need, to find a like replacement.

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 Post subject: Re: GE Micro C-2450A questions
PostPosted: Feb Tue 18, 2020 4:43 pm 
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Location: Colorado Springs, CO
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AFA the tiny screw, I have a metal hardware junkbox with all manner of smaller screws, bolts, springs, connectors, etc., which is sorta what you need, to find a like replacement.

yeah, I have several pounds of screws, nuts, springs, and several junker pocket radios to rob parts from, and none are tiny enough to fit there. Maybe I just haven't dug deep enough to go all the way to the bottom of the box where the little things accumulate.

I like your idea about the electrolytics. I'm so used to replacing them in pre-PCB radios that I didn't really think about that here. I have very little experience working little radios.

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 Post subject: Re: GE Micro C-2450A questions
PostPosted: Feb Wed 19, 2020 1:40 am 
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I have one of these cute little clock radios as well, but unfortunately the original battery did extensive damage to the circuit board on mine, so I never got it working again.
This model is interesting in that it's one of the first to use an integrated circuit, which is buried somewhere in that dense forest of parts.


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