Building an iPod Adapter for Vintage Radios

           

Many antique radios and TVs have a Phono jack that lets you connect a record player. This article describes a simple adapter that lets you plug an iPod or similar audio device into that jack.

With this adapter, your vintage radio can play anything from your iPod: recorded music, old-time radio shows, audio books, or content streamed from the Internet. The adapter converts your iPod's stereo output to mono and boosts the output. It also electrically isolates your iPod from the radio chassis, and best of all, it requires no power!

Here's a photo of the completed adapter, mounted in a little plastic project box.

The next photo shows the adapter's internals. Also shown are my iPhone, a standard iPod/iPhone audio/video cable, and a standard audio cable with phono plugs.

Schematic and Parts List

The iPod adapter can be built in an evening and it uses common parts available at Radio Shack and similar sources.

Quantity Part Radio Shack #
2 Audio transformer 2731380
1 Project box 2701801
2 10 ohm resistor 2711101
3 Phono jacks 2740852

For your convenience, I listed the part numbers of Radio Shack parts that I used. Note that Radio Shack may change part numbers or discontinue products at any time, so if you don't find those exact part numbers, search their website (or another supplier's site) for equivalent items.

Here is the schematic diagram:

Building the iPod Adaptor

In this simple adapter, the layout of parts is not critical. I used a ready-made plastic project box, but you could use anything similar, even a large pill bottle or 35mm film container.

You'll need to make holes for two phono jacks (the inputs) on one end and one phono jack (the output) on the other. I drilled holes and enlarged them a bit using a Dremel tool. You could also melt holes with a soldering iron.

I glued the transformers into the box and connected the few parts using point-to-point wiring.

As shown in the previous photo, you plug the two input plugs into the pair of jacks on one end, and the single output plug into the single jack on the other end.

I used phono jacks for the input because I use an iPod audio/video cable to play music or movies on various devices. If you prefer, you can substitute a stereo mini jack and matching cable for the input.

Using the iPod Adaptor

If your radio has a jack labeled Phono, simply plug the adapter's output plug into that jack and switch your radio to Phono mode. For instance, here's the Phono jack in the back of my Stromberg-Carlson 440M console:

The iPod adapter mixes the stereo input to mono and it boosts the output to make a good match for vintage radios. If you connected your iPod directly, you would likely find the volume too low, compared to traditional inputs.

A few 1940s radios had jacks labeled TV or Television. These are also audio input jacks, designed for use with rudimentary prewar TVs that lacked built-in audio. If your radio has a TV jack, you can use it like a Phono jack.

Credit Where Credit is Due

I built this adapter using plans published in an Antique Radios forum discussion and the schematic is reproduced by permission of its creator, forum member processhead.

That discussion includes some talk of how the adapter works and some alternative construction techniques. Thanks to forum members Pbpix, processhead, and others for all of the good ideas.


This radio construction project, including all descriptions, diagrams, photos, and the underlying electronic design, is published here for the noncommercial use of radio hobbyists. You may print and reproduce these project instructions for your personal use. Commercial use of this material is not authorized.

©1995-2017 Philip I. Nelson, all rights reserved