MP3 Files to Old School AM Radio?

January 7, 2007 1:12 PM

I'd like to "broadcast" my MP3 based collection of classic radio drama and spoken word recordings so that I can listen to them on a 1930's era AM radio. There are all sorts of little USB to FM transmitters, but I can't find a convenient (as in, no soldering required) solution for AM. Any suggestions?

Also: Cost is a bit of an issue. I'd like to keep the bill below $50 if possible.

posted by aladfar to technology (11 answers total)

This? Line-in rather than USB, though.
posted by holgate at 1:25 PM on January 7, 2007

Thanks holgate - I came across that transmitter before posting. It comes to just *barely* less than $50 assembled, but I think it requires a separately purchased power adapter.

And its 1/4 mile range is a little more than I need. What I'm hoping to find is something similar to those little FM transmitter fobs for an iPod only capable of transmitting in AM. But such a thing might not exist . . .
posted by aladfar at 1:36 PM on January 7, 2007

Depending on how much work you want, there's this DIY kit.

I couldn't find it, but I keep thinking I've seen some reason why AM transmitters aren't as readily available as FM counterparts. Of course, it could just be the stereo vs. mono issue, which you wouldn't care about.
Very nice idea, though!
posted by niles at 1:57 PM on January 7, 2007

Ramsey Electronics makes kits, two of which are AM radio transmitters. Good outfit.

They require assembly, unfortunately, but it's something pretty easy and you might be able to sweet talk a techno friend into fabricating one for you.

Their two options are $35 and $99.

The $99 is better because it's frequency synthesized. You'll have some drift on your old radio, probably, but with both a transmitter and receiver drifting, you'll constantly be adjusting the receiver for good audio... big PITA.

It's outside your stated price range, but it's the one I plan on using for the same thing in the near future.
posted by FauxScot at 3:32 PM on January 7, 2007

First questions - does the '30's era AM radio actually work... and well enough? On the radio, can you find spots on the radio dial that aren't already occupied by commercial stations?

If the answers to all the above are all positive, then you'd probably have OK results using a small simple AM transmitter. You may have occasional problems with drift or interference, and you may have trouble getting the transmitter modulation just right.

Speaking personally, I would be very tempted to just arrange to feed the old radio's speaker directly from a small cheap amplifier. The sort of simple amp built into cheap computer speakers would work fine, I believe. This would be inexpensive, and frees you from all the transmitter and receiver tuning. Of course, that removes some of the radio romance too.

I have a big old RCA console radio to rebuild sometime, you've inspired me... got any good sources for downloading old radio shows?
posted by Artful Codger at 4:54 PM on January 7, 2007

Artful Codger: Radio Lovers
posted by niles at 5:03 PM on January 7, 2007 [1 favorite]

:)
posted by Artful Codger at 7:23 PM on January 7, 2007

Yes on Both counts Codger. I realize I could simply feed something directly into the speaker, but there's no romance in that. I want it to actually function as a radio!

Thanks much for the answers everyone - the exact solution I'm looking for doesn't exist, so I believe I'll buy one of the kits linked above. I've no experience working with signal drift, etc. but tinkering with that sort of thing is part of what I'm looking forward to.
posted by aladfar at 7:51 PM on January 7, 2007

I unfortunately can't find it but there's this toy AM transmitter (I recall it being sold as a DJ kit) where you could plug a CD player through the headphone jack and connect it to the thing and it'll broadcast on 1610 AM or some legal short distance frequency. Furthermore, it was only about $20.

Maybe someone could back me up here. I remember it was purple too and it was out not too long ago.

I'll have to find it and post a link. That should definately work for you.
posted by champthom at 9:48 PM on January 7, 2007

Dang. It was made by Wild Planet and it was called the "Radio DJ." Unfortunately, based on their site it doesn't look like they make them anymore.

But if you can get your hands on one, it'd be perfect for what you need.
posted by champthom at 9:51 PM on January 7, 2007

That's a great suggestion champthom! Sadly, the Radio DJ broadcasts at 1610 - most older radios (including the two that I own) only go to 1500.

Some research reveals that it's possible to hack the thing such that it will broadcast at 1500, but that gets into a little more time and work than I'm willing to invest.
posted by aladfar at 10:44 PM on January 7, 2007