AUX input jack for 67-72 AM radio

[69-72]

Originally Posted by BBrendal

Sweet!

Originally Posted by chuck69ss

Couple of thoughts:
1. A cap soldered to the case sounds like a tone control, rather than volume. These are stacked pots, right?
2. The easiest way to figure this out is with an oscilloscope. I have also used a set of headphones with one side tied to gnd and uses the signal lead to poke around and follow the signal path. You want to find the input side of the volume control.
3. I wish that had an AM/FM to figure this out. :-)

Maybe someone else has figured this out.

So I did the headphone thing. I found sound when I probed the blue wires on the circuit board, only problem is afterwards when I hook up my aux source to them it does go through but is very faint. There are also two different points on the board that the blues go to, one of them has two blues going to it, only one of them the source is heard over, the other point also plays the source when it is applied.



Edit: I discovered that when the source is hooked up to the blue wires it is not being amplified, volume stays at same level when power is removed from radio

[mikey2409]

Ok so I'm about to go to cell phone shack I mean radio shack to see if they believe in diodes resistors and all that fun electrical stuff still but before I leave I've read that the aux jack with 3 inputs works best and not the 5 and does it matter if it's stereo or mono and if I'm correct all I need is the 3 inputs cause all I'm doing adding a power signal and ground to the aux jack of so whiche wires should I be adding to or taking from since I'm more than likely going to running the out of the radio into the ash tray for a confined look

[frankslagoon]

I did my 70 just like Blkcorvair said and it works great.

[PAWS 72]

Originally Posted by mikey2409

Ok so I'm about to go to cell phone shack I mean radio shack to see if they believe in diodes resistors and all that fun electrical stuff still but before I leave I've read that the aux jack with 3 inputs works best and not the 5 and does it matter if it's stereo or mono and if I'm correct all I need is the 3 inputs cause all I'm doing adding a power signal and ground to the aux jack of so whiche wires should I be adding to or taking from since I'm more than likely going to running the out of the radio into the ash tray for a confined look

Get the 5 wire and follow the directions and everything will work.3 is not cheaper than the 5 pin. As far as I know the mod I done is still working. I divorced 2 years ago and the son got the truck . It was his mom's dad truck.

[ext5060]

Holy smokes.. That was a great info thread. Wish I had the nerve to try that!

[69-72]

I had my am/fm converted to an aux input recently so it is possible.

[serge]

Blkcorvair,
This is perfect. Hope to install this week. Will post results.
Thanks

[serge]

blkcorvair,
Followed your directions and it works great.
Last year I installed stock AM radio (with a speaker from Turnswitch) but used it very little due to poor reception. Now with this AUX jack set-up I get to enjoy the great sound the speaker puts out and maintain stock look.
Thanks for the post.
Serge
P.S. The only thing that is a little discouraging is the loose connection when patch cord is plugged in jack. Got them from radio shack.

[serge]

6 month update.
This set-up is still working great. I use it with my MP3 player all the time.
By far the best 5 dollars I have spent on this truck.
Thanks again Blkcorvair.

[rockyrivermark]

Just did this to mine old am today
So cool!
Thanks.
Posted via Mobile Device

[lsversaw]

This is absolutely the cheapest/best way to connect any music player or phone to your audio system. The only shortcoming, if there is one, is that you'll hear mono, not stereo.

If your radio isn't working, you can just connect an aftermarket amplifier between your phone and original speaker. You can get a name-brand, highly-rated amp for under $100.

If you go the route of an aftermarket amp, you can also wire your original-radio on/off/volume control to manage on/off and volume through the amp.

I can add all sorts of features to original radios -- aux input, Bluetooth, USB, FM stereo, more power, pre-amp outputs -- but I realize that it's expensive compared to DIY options like the one descibed here, and not the best option for everyone.

[rockyrivermark]

Originally Posted by lsversaw

This is absolutely the cheapest/best way to connect any music player or phone to your audio system. The only shortcoming, if there is one, is that you'll hear mono, not stereo.

If your radio isn't working, you can just connect an aftermarket amplifier between your phone and original speaker. You can get a name-brand, highly-rated amp for under $100.

If you go the route of an aftermarket amp, you can also wire your original-radio on/off/volume control to manage on/off and volume through the amp.

I can add all sorts of features to original radios -- aux input, Bluetooth, USB, FM stereo, more power, pre-amp outputs -- but I realize that it's expensive compared to DIY options like the one descibed here, and not the best option for everyone.

Posted via Mobile Device

[rockyrivermark]

if I get the 2k resistor what wattage should be used?
They vary and I didn't see it mentioned
Thanks.
Posted via Mobile Device

[notchbackgta]

1/4 watt should be fine for this, but you could do a 1/2

[69Tom]

Seeing as photobucket sucks does anyone have any diagrams or photos of this being done? Thanks.

[PAWS 72]

Originally Posted by 69Tom

Seeing as photobucket sucks does anyone have any diagrams or photos of this being done? Thanks.

Go to the very first post. All the photos are still there as of now.

[PAWS 72]

For a few that wonders. Just resurrecting from the dead. Nearly a year later.

[FL71C10]

Has anyone had any problem with the "noisy" sound after a while from corrosion of contacts with this mod? I asked my engineer friend if he could help me with this, but he is concerned that is the contacts corrode the sound would get noisy. He said something about it being a very low powered circuit,and that any corrosion might negatively affect the sound quality.

Any thought?

Thanks.
John

[FL71C10]

No comments or suggestions?

[Kidd-7]

I do agree being a low power circuit it will be more susceptible to noise induced from corrosion. The resistance created by any corrosion would not have to be very high to have a significant impact on the audio, again because of the audio signal being low. I can not speak to this in practice though.