Crossover for a Motorola Sk521D console record player

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Randomsandy
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Crossover for a Motorola Sk521D console record player

Post by Randomsandy » 17 Feb 2019 23:31

Hey all! My first post here, hoping to find some help. I just picked up a Motorola console record player, SK521D. It is missing a crossover on one side of the speakers. I’ve googled everything and can’t figure out where to purchase one? I took a picture of the other one and it had the numbers 23C63517A02 Motorola Audio Crossover. Does anyone have any recommendations? Thank you in advance!

Coffee Phil
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Re: Crossover for a Motorola Sk521D console record player

Post by Coffee Phil » 18 Feb 2019 00:39

Hi Sandy,

Welcome to the forum.

I’m guessing that the crossover is not too complicated. I’m guessing that the easiest thing to do is copy the other crossover. There are many site which sell the parts to make crossovers. The caps will likely be labeled, but the inductors may have to be measured. My new DVM does measure inductors so if you can’t find someone closer you can send it to me to measure.

Phil

Randomsandy
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Re: Crossover for a Motorola Sk521D console record player

Post by Randomsandy » 18 Feb 2019 00:43

Thank you phil! I’m going to contact a local restoration shop first. I have a photo but that won’t help, and I can’t upload it. If I don’t have any luck I will message you. I appreciate the reply!

Spinner45
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Re: Crossover for a Motorola Sk521D console record player

Post by Spinner45 » 18 Feb 2019 02:25

Randomsandy wrote:
17 Feb 2019 23:31
Hey all! My first post here, hoping to find some help. I just picked up a Motorola console record player, SK521D. It is missing a crossover on one side of the speakers. I’ve googled everything and can’t figure out where to purchase one? I took a picture of the other one and it had the numbers 23C63517A02 Motorola Audio Crossover. Does anyone have any recommendations? Thank you in advance!
The crossover for those is a simple capacitor in series with the tweeter - simply find the other channel and aquire one of the same value.

Randomsandy
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Re: Crossover for a Motorola Sk521D console record player

Post by Randomsandy » 18 Feb 2019 03:34

I do have the other capacitor (not crossover....that’s what it says on the outside of the capacitor). Still doing more research on where to buy them, but I have a place I’ll contact tomorrow. I do appreciate the reply!

Alec124c41
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Re: Crossover for a Motorola Sk521D console record player

Post by Alec124c41 » 23 Feb 2019 15:52

I might guess that it is a 4 microfarad capacitor. This was commonly used to cross at around 4000 Hz.

Cheers,
Alec

Spinner45
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Re: Crossover for a Motorola Sk521D console record player

Post by Spinner45 » 23 Feb 2019 18:01

Alec124c41 wrote:
23 Feb 2019 15:52
I might guess that it is a 4 microfarad capacitor. This was commonly used to cross at around 4000 Hz.

Cheers,
Alec
Guessing is dangerous Alec.
According to my schematics on that series of consoles, they use 8 or 25uf depending on the model and speaker lineup.

Alec124c41
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Re: Crossover for a Motorola Sk521D console record player

Post by Alec124c41 » 23 Feb 2019 20:18

If you have schematics, "you da man."
In this case, there is no danger. That would have been enough to protect the tweeter, though.

Cheers,
Alec

Big B5515
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Re: Crossover for a Motorola Sk521D console record player

Post by Big B5515 » 23 Feb 2019 20:36

8 uf (or mfd) sounds about right for a tweeter of 3.2 - 4 ohms. 25 uf would be for a larger midrange sized speaker, and after having one fail, vent loudly, and begin leaking, might suggest replacing both at this age. I would say parts express should have an affordable non- polar electrolytic, or film replacement of similar value and audio oriented user friendly website. Digikey would be another option with much greater parts inventory i've used. I used a Panasonic polypropylene film capacitor from here that worked just fine, don't be afraid to use a higher voltage rating, or wire in one that's made different. The value sets the crossover frequency.

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