EASY RADIO REDUX

Gift of the Magi

Talk of Wise men ... oops! ...persons... bearing gifts?

Well, I too had such an experience --though not in December.

When a younger cousin came to me last month with a smile and proferring a packet, asking  me to "take a look" when I was free, I never had an idea what I was letting myself in for. That was how the old, battered transistor radio migrated to my table. Opening the package that weekend, I discovered a cute little AM/FM box that had seen better days, but which clearly was a treasured friend, especially on busy mornings when radios regulated the schedules of busy people rushing "to beat the clock".

Opening the small cabinet turned out to be a big task, even with a generous spraying of that wonder formula WD-40 and application of muscle power. Months (years?) of being forgotten at the back of some damp cupboard had invited rust and corrosion. Somebody had left the old batteries in, which had leaked and corroded the innards.

The rusty innards...

The printed circuit board, all the switches, and even the little speaker was rusted and corroded. It was a total write-off. My cousin's face fell. Her fond hope was for it to be given just a wee bit of life so that it will produce some nostalgic sounds once again... But, alas!


Operation...

On a whim, I removed all the old junk and cleaned up the cabinet at the kitchen sink, and stood the now pristine looking cabinet on the shelf--for inspiration! It stayed there for a few days. One evening at the electronics spares shop (another dying breed!) hunting for some parts for my current project, I overheard a couple of young girls enquiring if the radio kit had come. I was all ears as I knew that sources for radio and cassette player spares had dried up long ago.

The FM/USB/SDC player

The shop owner, my old friend, pulled out a few small packets, connected up a couple of AA batteries and Voila! a nifty display came up reading 90.8, and music blared out of the small speaker laid face-up on the counter top. It had a small modern high-density pcb and front panel.

The modern PCB

The gizmo was a stereo FM tuner, a USB and SD card music player, with a small display, an Aux input AND a full-function remote -- all for less than Rs 200! Hook it up to an amp or to a small amp kit (just about Rs 60!), and you were in business. Ah, just what the doctor had ordered! I took home a couple of them without a second thought.

... Success!

With enthusiasm, I set to work. Wonder of all wonders, the old mains transformer and power supply board from the radio was working all right.

Good! That gave me 8-9 V DC. I drilled a few vent holes for the transformer, replaced all the old electrolytics, wired up some 1.5 kpF caps across the rectifiers for noise suppression

The mains power supply

(Radios are particularly sensitive to all sorts of electrical noise, especially when working on a mains power supply. So, for insurance, I added an R-C "snubber" too at the output of the PSU.), added a 5V regualtor for the tuner/player module, and tested it. I had opted for a 1-inch-square mono audio pcb

Typical TBA 820 audio amp

with a TBA820 chip that was okay with supplies up to a maximum of 12 V. All checked out fine.

Now, the ten-lakh rupee question! (No, I'm not comfortable working with millions,in rupees or dollars or Euros!) Where to mount the little player?? A couple of days of staring at the radio finally brought some inspiration. Put it on the top, where the little push buttons would make it look like an old two-in-one cassette player!

The 2-in-1 look

This also would call for minimum "surgery", and did not spoil the "original looks". The old AM/FM bandswitch slot at the back came in handy for mounting the combo on/off/volume control.

Back view - note vent holes

Easy!


Now it was only a matter of wiring up everything neatly,

Note: Be careful while connecting up

cleaning and connecting the telescopic antenna, and closing up the cabinet with new screws!

Playing music from a USB drive

A few hours' work had given a seond lease of life to an old beauty, and that too in a contemporary new digital "avatar"! My cousin's open-mouthed look of disbelief and happiness was more reward than I had anticipated.

Tea table beauty!

Well, wasn't it Shakespeare who said " All is well that ends well"?!!

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