Any info on adding an aux. input to vintage radio?

[CandyAppleRed 10]

I've been searching without luck for information on adding an auxiliary input to a vintage, in my case 1975 Ford AM/FM car radio. All I seem to be able to uncover is info about FM transmitters, FM modulators, cassettes with plugs hanging out and using the remote CD changer input. Non of these are really what I'm looking for since the radio doesn't have a cassette or CD player, and FM transmitters and modulators typically have very poor sound quality. I'd like to learn how to hard wire directly into the circuit. Any help would be appreciated.

[Jayru 17]

There was an article in Hemming's Muscle Machines a while back how to do that very thing! Don't know if they offer their content online though. Maybe you can track down the issue and backorder it?

[Pakrat 1,043]

Check out this link and consider contacting member Danno, if you don't want to pay him to do it he may tell you how.

 

http://www.1969stang.com/mustang/forum/showthread.php?t=9478&highlight=radio

[CandyAppleRed 10]

Thanks for the tip Jayru. Do you remember if the article was months back or years back? I found HMM online and they have an archive. But it's tedious to search as they, like most magazines, use "flowery" titles to the articles.

[CandyAppleRed 10]

Or is it possible that you remember which section it was in? "Features", "Ask Ray", or maybe "Tips"?

[CandyAppleRed 10]

Check out this link and consider contacting member Danno, if you don't want to pay him to do it he may tell you how.

 

http://www.1969stang.com/mustang/forum/showthread.php?t=9478&highlight=radio

 

Thanks Pakrat. I did find that thread during a search. Out of respect I wouldn't ask for information from someone who does it professionally. But I did PM "flight96" who states he has done this. No reply as of yet.

[69RavenConv 286]

It's not a difficult mod, but of course you need to get it right the first time. I've never done it, but here's a thread you may find helpful.

 

http://tinyurl.com/3cw5zn5

 

And here's a guy that will do it for you ($50 in 2009), I know there's others.

http://tinyurl.com/3cw5zn5

[lincoln8 10]

Hello, I'm new to this forum and I hope this may help. I just had my stock am radio converted to am/fm with an aux imput by woodsradio.com. It works great and may be worth your while to check it out. Also would like to say thanks for all the great info I have read in the archives.

[EastYorkStang 63]

Woodsradio doesn't work. Do they have another website?

[Grabber70Mach 107]

Woodsradio doesn't work. Do they have another website?

 

http://www.woodradios.com/ maybe this is it.

[lincoln8 10]

Sorry it was a little late when I posted, it's woodradios.com.

[danno 128]

I have done what you are asking about several times. I did it for myself and started doing it for others who wanted the same thing. I am doing it now for someone who wants MP3 stereo for his AM/8 track. That way he can use his MP3 for music or as a FM receiver and keep the car original.

 

When I do this mod, you can switch from the normal AM/FM to a remote audio input. The remote audio input plugs into the headphone jack on any typical MP3, CD player, or even a TV. Then you can use the knobs on your radio to adjust volume and balance. It has a seperate toggle switch to change between normal radio operation and remote input to it. When I do the mod, I also put in a USB port to supply power to your MP3 so the battery is always charged.

 

So in my system, I have my MP3 player in the console glove box. It has 2 wires to it, the audio (in the headphone plug) and the USB connection for voltage to it. I click the switch on the dash to change between normal AM/FM and MP3.

 

So that is how it works. How to do it, though, is not an easy thing to explain. You need to take the whole radio apart, find the right parts to modify, do the mod, and install the relay, install the USB voltage supply, do all the wiring and connections, and put it all back together correctly. That part about putting it all back correctly can be a real challenge the first time.

 

If you have electronics knowledge, know the difference between a resistor and capacitor, know how to solder to a printed circuit board, and know how to read a schematic and layout, then there is a chance you could do it. Some radios are a lot more complicated than others, though. The mod is a lot more difficult on the original 69 AM/FM ( the one without the balance knob below the station select buttons) and some other radios. I would not even try to explain how to do it on those. But the average AM/FM from the 1970's it does work on easier.

 

I typically charge about $80 to do the mod to a working radio, and I am not making much money doing this, believe me. Just enough to pay for materials and beer while doing it. I know others do this also for a business, for me it is just to help others.

 

If you can fill the pants and want a challenge, I will tell you or anyone else how to do it. Like I said, I am not in it for the money so I am happy to tell others how to do it. But I don't want to waste your time and mine if I need to start with a review high school electricity.

 

So in a nutshell, the modification generally amounts to the following. There is an amplifier IC in radio right after the AM/FM selector switch. This IC is under the pushbutton station control mechanism, so that all has to come out. The output of this amp goes to the volume, balance, and tone knob controls, and finally to the output amplifier. The amplifier IC has 2 outputs, one for left and one for right. These outputs go to resistors, usually 6800 ohms. You need to cut the trace between the amplifier and these resistors, and that is where you wire your remote audio input.

 

I can go over it in some more detail, though, if you want. If what I said in the previous paragraph makes sense, along with the "filling the pants" part, then you can do it.

 

Let us all know what your next step is.

Danno

[Jayru 17]

Thanks for the tip Jayru. Do you remember if the article was months back or years back? I found HMM online and they have an archive. But it's tedious to search as they, like most magazines, use "flowery" titles to the articles.

 

I will try and look through my back issues next weekend to see if i can find it for you. I believe it was within the past year. I've had a subscription for about two years though.

 

It definitely was a article. I think it even had a shot on the cover of the issue about it. Something like "Update your original radio for modern accessories" etc...

Edited April 11, 2011 by Jayru

[CandyAppleRed 10]

danno, you are currently my newest bestest friend! :P

 

One way or another I am going to learn how to do this. I may pick a radio up from the junk yard to practice on. I don't want to fry my NOS 1975 radio.

 

I messed with electronics in high school which was 35 or so years ago. Even made a few of my own pc boards for projects. I have a small soldering iron and fine rosin core solder. I think I may even have a few soldering heat sinks around here somewhere. I do know the difference between a resistor and a capacitor. I have to say though.... I have no idea what you mean by "fill the pants" beyond the literal meaning. I hope that alone doesn't disqualify me from being handed the keys to auxiliary input nirvana!

[danno 128]

Ok, I appreciate someone willing to take on a challenge like you are about to do. The first thing you need to do is to take off the top and front. The whole assembly with the station control pushbuttons all comes off as one piece. The the potentiometers on the left side for volume, etc, stay soldered to the circuit card.

 

There are small 3/16 inch hex head screws on the bottom side that need to be removed, but the panel on the bottom stays attached. You need to take off the gear drive for the station select knob, there is a small screw on the side near the gear that is the trick to this.

 

There is a circuit card assembly mounted verticle right behind the station select mechanism. This comes out with the mechanism. It attaches to the main circuit card ( the one across the bottom) with little spring clips, so it just pulls away from it.

 

There are a couple wires that need to be cut, remember where they go so you know where to put them back. Some of the wires are attached to the main circuit card with "quick connects" so you can just pull them and they come right off, no need to cut.

 

The front metal panel and the black plastic around the buttons all come off as one piece, you do not need to take that all apart.

 

So start looking it over and let me know when you get the whole station select mechanism removed.

[danno 128]

By the way, when you get it apart take a couple photos of the circuit card and attach them to the reply. I want to make sure what you have is what I think you have.

[CandyAppleRed 10]

danno, thanks so much for the assist. I wasn't expecting to tackle this immediately. My radio is at the garage where I am restoring my Mach 1. An hours drive round trip. That's why this restoration has dragged on for so many years. It's difficult to just pop out there and work on it. I will however drive out there, get the radio tomorrow and catch up on what you have posted so far. I don't think I will install the usb power cord. I doubt I will be doing any long cruises in the car. The 8 hour battery life is way more than enough for my use. It's mainly the auxiliary input I'm interested in. I have a 6' mini stereo plug extension cord. I was thinking of just cutting the female end off and use the cord for my input. I have the slide out ash tray below the dash (no console). I planned to coil up the cord and tuck it into the ashtray when not in use. I will also pick up a small toggle switch for the radio/Aux switch. Do I just need a simple SPST on - off switch, or something more complicated?

 

Here's a link to the auction I got the radio from. Doesn't show the innards but you may be able to tell if it's the radio you thought it was.

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150581601327&viewitem=&sspagename=STRK%3AMEWAX%3AIT

 

Thanks again for your help. It is much appreciated!

Jeff,

[69gmachine 15]

$80 sounds like an absolute bargain to me! I tore an AM/FM 8 track apart, discarded all the 8 track drive parts with the intention of adding the aux in to the 8 track's pick up. My goal was to make it switch to the aux in and automatically switch off the radio just like an 8 track did. I couldn'tmake it work. That was almost 2 years ago. Now I'm pretty sure I'll never be able to put humpty dumpty back together again lol. So, Danno, if you're willing to modify my 8 track and re-assemble it, send me a PM with your shipping address.

Edited April 13, 2011 by 69gmachine
too many s's

[danno 128]

Jeff, I will keep watching the forum for updates on your porgress. My only other comment is about the USB voltage for your Mp3 player. I understand 8 hours is plenty of time, but it does mean you have to remember to take it out of your car and recharge. I have a cheap MP3 player I leave in the car, plugged in and ready to go all the time.

 

To 69gmachine, the $80 is usually for a working AM/FM from the 1970's or 1980's. I am not familiar with an AM/FM 8 track. I am doing the mod to an 1968 AM/8 track now, and will find out how difficult that is. I know it can be done to yours, but a lot of the work is taking the thing apart and putting it all back together. That 8 track thing could make it a lot more difficult to take it apart. As yours is already apart, it could be difficult to get it back together. Let's wait a bit until I get the one I am now doing first. My initial guess is that I could do it, but it might be a couple bucks more because of your 8 track. Follow this thread and we will keep in touch.

[CandyAppleRed 10]

danno, I just got back with the radio. I'm going to hook it up to some speakers and a cycle battery to confirm it works since I haven't tested it out yet. After I confirm it works to start with, I'll get out my hammer and crowbar and gut the thing. :P

 

I'll snap some photos after I get her opened up. And post my progress.

 

Thanks.

Jeff,

[CandyAppleRed 10]

Okay. I was able to gut the radio. Clear instructions made it a snap! Nothing unexpected, nothing difficult. Photos below, I think... First time posting pix to this site.

 

Look familiar?

 

 

 

 

 

 

 

 

 

 

[CandyAppleRed 10]

Oh, I didn't have to clip or unplug any wires. All connections seemed to be made via the spring contacts with the rear most circuit board. Doesn't seem the most reliable to me. I will clean those spring things with 1000 grit sand paper before reassembly.

[69gmachine 15]

Nice pics! Could you show where you made the attachments? My radio looks very similar, so maybe I can find the equivalent pick up points. However, I have a concern about my radio's power antenna. It came from a '77 T-bird, and there's a sticker that has a warning that it must be connected to a power antenna.

[danno 128]

Jeff, good pictures. The model you have is different from others I have seen, but the change has to be about the same. The change is made in the circuit card that is on the bottom, under the pushbutton station selector mechanism. That is why I said taking it apart is a mess, because you are not there yet. Before you do that, there could be a way to do it from the bottom of the circuit card. I need to review the schematic on it to see if it is possible. In the mean time, take a picture of the bottom, just so I have something to work with.

 

I will find out if it is necessary to take the station selector out. Also, do you have the model number of the radio, from the side? Something like D0ZB-122944-EB.

 

The saga continues,

Danno

[CandyAppleRed 10]

Of course, I have to have the odd ball.

I'll be right back with the info.

Does your schematic give the color code for the speaker wires? I have a jack plug with 5 connections. A black one with a white tracer I assume all speakers get grounded to. And 4 colored ones, a pink with blue tracer, a pink with green tracer, a white with green tracer and a orange with green tracer. Odd colors that are difficult to pair together into front/back, left/right pairs.

 

Be back in 5 with the photo and number.