Replacing a Japanese freq fm tuner to USA freq fm tuner - Electronic Circuits Projects Diagrams Free

meepers · 24th April 2004, 02:32 AM

Hello every one. I am interested in converting a Japan market car stereo to receive us stations. Its a digital stereo with the typical lcd screen. I have a basic knowledge of electronics, and the soldering the US receiver in place I can handle. What I would like to know is if anyone has attempted such a thing and knows if I would need to change the programing in any of the IC's to know to look for the 88-108 instead of the lower freq. thanks in advance for any help.

Tim

Russlk · 24th April 2004, 04:08 AM

Unless you are very knowledgable, I don't think that modifying the frequency synthesizer is a good idea. You would also have to tune the RF and Mixer coils.

meepers · 24th April 2004, 05:37 AM

I'm sorry, I guess I did not explain exactly what I was intending to do. I will physically replace the tuner in the head unit completely

http://www.mitsumi-components.com/Ca...m/index_e.html

it looks like there models are followed by the region they are for. J for japan and A-E for America and Europe

The particular unit I have is a mitsumi tuner and they make 2 different region tuners. what I need to know is if I change the tuner completely, does the main control IC that handles the voltage change for tuning, and presets and data bus for the lcd and such, does it need to be replaced or will the unit be able to scan the new freq's and show them on the display? I'm guessing that if it does, I would either need a donor stereo with the same IC set or need to be able to program the chip to recognize the new expanded range. I hope this clarifies what I am hoping to do, and if anyone has any knowledge on the workings of how a digital tuner and works and what I would need to do, I would love to undertake this project with atleast a point in the right direction. Thanks again!!

Tim

**Nigel Goodwin** · 24th April 2004, 01:07 PM

You've never mentioned the make and model of the stereo, Mitsumi are probably only the manufacturer of the tuner unit (they also make RF modulators for VCR etc.).

You really need to find a service manual for the complete unit, it's quite possible that the existing controller can work with either tuner type - often by making (or cutting) a wire link, or (more recently) setting an option in memory.

meepers · 24th April 2004, 03:42 PM

Well hopefully the unit I will be doing this to will be here in the next few days. I will try to get a hold of the fsm and see what the schematics show. Its a factory honda option car stereo that was only available in japan in the civic. The brand is Gathers, but Honda contracted Alpine, Pioneer and Kenwood for the option line depending on the model. So it could be any one of them. Just looking at the unit it looks like it might be a kenwood. I have a few receivers laying around that have been taken apart. I'm hoping that it might be a similar layout to one that I have so if I need to I could steal some of the main IC's. I know the lcd controller and stuff will be different, but I am really hoping that just swapping the Tuner module will be the ticket. I will wait till I get the new deck and shoot some pics of the inside and see if I can find anything online about the particulars of the components inside.

Thanks

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24th April 2004, 02:32 AM	(permalink)
meepers	Replacing a Japanese freq fm tuner to USA freq fm tuner Hello every one. I am interested in converting a Japan market car stereo to receive us stations. Its a digital stereo with the typical lcd screen. I have a basic knowledge of electronics, and the soldering the US receiver in place I can handle. What I would like to know is if anyone has attempted such a thing and knows if I would need to change the programing in any of the IC's to know to look for the 88-108 instead of the lower freq. thanks in advance for any help. Tim __________________ If you make a cow laugh, does milk come out her nose?

24th April 2004, 04:08 AM	(permalink)
Russlk	Unless you are very knowledgable, I don't think that modifying the frequency synthesizer is a good idea. You would also have to tune the RF and Mixer coils. __________________ see my website: www.geocities.com/russlk

24th April 2004, 05:37 AM	(permalink)
meepers	I'm sorry, I guess I did not explain exactly what I was intending to do. I will physically replace the tuner in the head unit completely http://www.mitsumi-components.com/Ca...m/index_e.html it looks like there models are followed by the region they are for. J for japan and A-E for America and Europe The particular unit I have is a mitsumi tuner and they make 2 different region tuners. what I need to know is if I change the tuner completely, does the main control IC that handles the voltage change for tuning, and presets and data bus for the lcd and such, does it need to be replaced or will the unit be able to scan the new freq's and show them on the display? I'm guessing that if it does, I would either need a donor stereo with the same IC set or need to be able to program the chip to recognize the new expanded range. I hope this clarifies what I am hoping to do, and if anyone has any knowledge on the workings of how a digital tuner and works and what I would need to do, I would love to undertake this project with atleast a point in the right direction. Thanks again!! Tim __________________ If you make a cow laugh, does milk come out her nose?

24th April 2004, 01:07 PM	(permalink)
Nigel Goodwin	You've never mentioned the make and model of the stereo, Mitsumi are probably only the manufacturer of the tuner unit (they also make RF modulators for VCR etc.). You really need to find a service manual for the complete unit, it's quite possible that the existing controller can work with either tuner type - often by making (or cutting) a wire link, or (more recently) setting an option in memory. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

24th April 2004, 03:42 PM	(permalink)
meepers	Well hopefully the unit I will be doing this to will be here in the next few days. I will try to get a hold of the fsm and see what the schematics show. Its a factory honda option car stereo that was only available in japan in the civic. The brand is Gathers, but Honda contracted Alpine, Pioneer and Kenwood for the option line depending on the model. So it could be any one of them. Just looking at the unit it looks like it might be a kenwood. I have a few receivers laying around that have been taken apart. I'm hoping that it might be a similar layout to one that I have so if I need to I could steal some of the main IC's. I know the lcd controller and stuff will be different, but I am really hoping that just swapping the Tuner module will be the ticket. I will wait till I get the new deck and shoot some pics of the inside and see if I can find anything online about the particulars of the components inside. Thanks __________________ If you make a cow laugh, does milk come out her nose?