Old Radio To MP3 Player

Snowman999

Member
I KNOW NOTHING about electronics old or new. But, I do know from watching a youtube video, an old radio can be turned into an MP3 player. Watching the video I'm positive it's too advanced for me to do. But, I do have some questions that perhaps someone might know the answer to.

Here's photos of my old radio which works. I paid a few bucks at an estate sale. I think it was $5. The radio the guy converted did not work.

003.JPG004.JPG

In the video the guy removed most of the guts. He left 2 tubes and the original speaker. Since he removed most of the guts, wouldn't that change the sound going to the speaker? If the person played Big Band music through it, would it sound a little different because most of the tubes are gone?

In my little mind I liken it to listening to vinyl versus CD. I do hear a slight difference.

WOULD IT BE POSSIBLE to do the following (remember I'm a moron. But, it does kind of make sense) If I took the earbuds I use as headphones for my MP3 and removed the earbuds. Took the open wires and attached them to the wiring in the back (which looks to me to be used as an antenna) would I be able to find a frequency that will play the music?

The reason I just don't try it is, the guy in the video spoke about something bad happening if you attached to your MP3 player to the board in the radio. I don't want to do that. But, since I had no idea of what he was talking about in the first place, I could be doing the same thing attaching it to the wiring in the back.
 

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Hey!
First thing's first and that's safety. That looks like it might be a mains powered boyo? If so, it'll gladly kill you so...I'd do nothing until you're 100% certain of the plan, and safety.

Next up, it's always useful to have a schematic if you're going to work on anything like this. Is that something you can get?

You mentioned the guy ripping out a lot of the internals - That sounds normal enough but not strictly necessary
Much of the circuit is going to be the radio tuner then the rest is going to be amplifier.
Quite often the junction between the two is very clear on a schematic either because you know what you're looking at, or because there's already a volume pot right between the two.
In cases where there is an existing volume pot right at the start of the amp portion of the circuit it's pretty simple to disconnect that and take it as your point of entry.

Another option would be to splice a switching jack into the circuit and mount it somewhere on the cabinet so that you can plug in and use it as an amplifier,
but the radio functionality is still preserved.

Maybe stating the obvious here but this radio is going to be mono and your mp3 player will be stereo so you'd need some way of summing L+R also ( or, better yet, get two radios. ;) )
That might be as simple as joining the two but hopefully someone else can tell you that for sure.

If it's something you're interested in but not very confident about consider trying the same thing on a 9v battery radio first.
Even if it's a relatively modern transistor radio the basic idea is still going to be the same and you have the freedom to tinker and play and poke without worrying about any danger.
You might even get a fun portable guitar amp out of it.

Edit : Looks like that might be a field coil speaker - I think that's the right name?
Instead of a fixed permanent magnet, like we'd usually see these days, they used an electromagnet instead and, therefore, require mains power.
Not impossible to use but it's something that would put me off.


...took the open wires and attached them to the wiring in the back (which looks to me to be used as an antenna) would I be able to find a frequency that will play the music?
No, but...
You could just get a little FM transmitter and plug your mp3 player into that, then tune the radio to its frequency.
You get the result you want without any tinkering.

Not 100% sure on the legality of those - I think it might depend on power/range and where you live.
 

Snowman999

Member
Hey!
First thing's first and that's safety. That looks like it might be a mains powered boyo? If so, it'll gladly kill you so...I'd do nothing until you're 100% certain of the plan, and safety.

Next up, it's always useful to have a schematic if you're going to work on anything like this. Is that something you can get?

You mentioned the guy ripping out a lot of the internals - That sounds normal enough but not strictly necessary
Much of the circuit is going to be the radio tuner then the rest is going to be amplifier.
Quite often the junction between the two is very clear on a schematic either because you know what you're looking at, or because there's already a volume pot right between the two.
In cases where there is an existing volume pot right at the start of the amp portion of the circuit it's pretty simple to disconnect that and take it as your point of entry.

Another option would be to splice a switching jack into the circuit and mount it somewhere on the cabinet so that you can plug in and use it as an amplifier,
but the radio functionality is still preserved.

Maybe stating the obvious here but this radio is going to be mono and your mp3 player will be stereo so you'd need some way of summing L+R also ( or, better yet, get two radios. ;) )
That might be as simple as joining the two but hopefully someone else can tell you that for sure.

If it's something you're interested in but not very confident about consider trying the same thing on a 9v battery radio first.
Even if it's a relatively modern transistor radio the basic idea is still going to be the same and you have the freedom to tinker and play and poke without worrying about any danger.
You might even get a fun portable guitar amp out of it.

Edit : Looks like that might be a field coil speaker - I think that's the right name?
Instead of a fixed permanent magnet, like we'd usually see these days, they used an electromagnet instead and, therefore, require mains power.
Not impossible to use but it's something that would put me off.



No, but...
You could just get a little FM transmitter and plug your mp3 player into that, then tune the radio to its frequency.
You get the result you want without any tinkering.

Not 100% sure on the legality of those - I think it might depend on power/range and where you live.

THANK YOU! You've reinforced all I was told late last night.

I looked up old radio clubs and found a few. The first thing I was told, I would probably burn my house down if I didn't recap the radio. I only understood the "burning the house down".

I've noted phrases to search for someone in New Jersey who can actually do the work.

After I posted this I thought of the FM transmitter, I had one years ago when I owned an ipod and wanted to use it in the car where I only had a cassette player. It turns out the cassette with the wire worked much better. But, since the radio would be stationary in the house I thought that might work. But, this radio (1934-35 440T, I had no idea) is only AM and Shortwave. So, that wouldn't work.

ONE THING you brought up:
These old swing and Hank Williams Sr recordings (I'd only be playing old music through it) they're still mono even on modern CD pressings? I hope so. If they made them stereo, that would kill my entire idea.
 

Ponder5

Member
I love these projects. Done several.

Have one to do, but the cabinet isn't really spiff. It'll need some cleaning and conditioning.
So the only priority that really matters is *appearance*. That's all.
Someone else might wanna restore the thing. Okay. They could. They get crazy. They go for restoration items like any resto types do. They'll even repackage capacitors to look like the original wax caps by putting a modern cap in the paper tube and filling it with yellow wax. I kid you not!
I am not such a resto guy.
And if you are not either, then all you care about is how it looks. Clean it up. New coat of wax. Maybe first see if there's any varnish or woodwork to do.

Then you gut everything. None of it is useful or competitive with anything you'll get today. Field coil speak? Ditch it. Sell it on ebay to the cork sniffers. If it's just the exact right one, they might give you something for it (after a thousand questions). Tube amps? Ditto (though the amps will bring bupkis).

Now you have a nice blank canvas to strap in all the goodies you desire. Parts Express is your friend.
Mount another speaker. Heck, mount 6 or 8 more speakers of various sizes. It's just some screws and maybe a cutout or two.
You could even take the front 4 knobs and exchange them for rotary encoders soldered into a controller.

Now if ALL you want is a 3.5mm plug to attach your iPod to, well, it's gonna be a lotta trouble. First things first, you gotta make sure the thing works. If it doesn't work right now, someone is gonna have to fix it. Then SOMEONE has to go in and run a tap for your jack. Or, like i say, gut the thing and put in a small stereo system.

If you're dead set on going mono, most modern recording collapse to mono pretty well.

These are fun. Just remember: unless you're going back to showroom new, exactly restored, you're gonna be stepping on someone's toes - that includes any aux inputs. So decide which way you wanna go and have FUN!
 

ecc83

Well-known member
I can only give advice WRT to UK and some EU radios.

First of all SAFETY! As Mr S said, mains V kills. In UK we had the ghastly "AC/DC" radio. Deadly things with no isolating mains transformer, if you don't see TWO iron transformers in there, one bigg, one small, walk away. Even if it has a mains traff the very first test isa a proper PAT especially the high voltage earth leakage test. Assuming it passes PAT my MO would be...

Strip out ALL the Cs and Rs and just leave the valveholders and transformers. You can loose at least two valves although I would also ditch the valve rectifier, and the heater wiring (but I would rewire as balanced. I hate hum!)

You would keep the output valve* and the triode/detector but if short of gain or, you wanted to fit T&B controls, keep one IF Pentode strapped as a triode for more gain (might then make a decent shredder!)

I have often thought of having a crack at this. I refurbed an old record player for daughter a couple of years ago. I have fixed more old radios and TVs than some of you have had hot lunches!

*A 'safe' was to do this is a total rip out then fit an amp module (look at "Vellmann" modules) and power it from a wall rat.
Also, removing some valves takes a few watts heater load off the ole traff. If fitting a sstate rectifier make sure the new caps are rated for the OFF LOAD extra volts! Engergized speakers? Yes not going to be nice sounding, v old but the coil was often part of the HT smoothing circuit so that need recalculating.

Dave.
 

ecc83

Well-known member
I have caught the bug! My daughter's partner is into retro kit, wanted an old telly a few months ago till I pointed out it was bloody dangerous, CRT neck exposed!
I have bought Marconi T42A radio for £20 and am in the process of gutting it down to mains and OP traffs and valve bases. Uses an EL84 op bottle (hole in it! but I have spares) so should be pretty pokey when done as the Silcon rects I shall fit will give more HT than the suspect EZ80. I just hope the existing mains traff is safe, no leak mains winding to chassis on a meter but not put 230V anywhere yet!

Not quite decided on circuit topology yet but I already have bought a Bluetooth reciever so I want him to be able to balance that against a guitar. Oh yes! Has a huge (for the time) 280x 120mm speaker just hope it is ok as I cannot find anything elese that drops in.

Will keep you all 'in the loop'.

Dave.
 

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