The Inimitable Thrill Of Repairing Radios
After a gap, I got two radios one after another, which gave me the thrill of repairing, as I always cherished the work very much. I began my electronics career by repairing Radios and it provides the excitement and vigor required for technicians like us to propel forward with full charge.
Case (1) Eveready Radio: This Radio belonged to my wife’s school classmate, who stays nearby, after purchasing a portion of my land several years back. The complaint was that the Battery spring was missing and it became dead after they replaced the battery. I opened and cleaned the Radio thoroughly, located the spring which had got dislodged from its position and put it back, lubricated the switches and controls.
Then thoroughly cleaned the cabinet to make it shine like new, as a part of my efforts to shine in front of my wife! (LOL) The radio worked very well and I was happy to see its performance. A free work as a part of goodwill. Let us have a look at a few pictures:
Case (2) Twinbird Radio : This is a Radio-cum-Emergency Light that belonged to a regular customer. He said that he heard crackling noises while using the Radio. He brought only the Radio part, which can be clipped on to the Emergency Light. This is a very small set which had AM/FM. Let us look at this lovely Radio:
I opened the set by removing two screws from behind. I saw a lot of dust collected inside the set and cleaned it thoroughly. The electrolytic capacitors gave a sick look and I resorted to my ever loving craze of replacing every one of them.
The screw for removing the Tuning knob was hidden under the dial sticker and it had to be peeled off. I saw a cap with rusted and broken leg! So, my intuition proved correct yet again!
The Radio was found using Sony CXA1191 IC, which has a built-in Audio Amplifier. You can have a look at its block diagram below:
Here are a few more pictures of this lovely compact Radio, taken before and while in the process of replacement of all eCaps and afterwards:
As you will notice from the third picture, one eCap 470/10V is having long legs as it is inserted inside the front cabinet.
In order not to waste time on finding the correct length of the leads, what I did was removing the sleeves of the old one and putting it in the new, holding the new eCap tightly on its sleeves and soldering it in its place. Otherwise the board will not seat snugly in its place. Then fit the board back and tried to see that the radio functioned very well. Forgot to mention that I had cleaned the potentiometer thoroughly, which was the cause for noises. But it had worn out carbon tracks, because of which I shorted the centre pin and hot pin, which solved the crackling noises. As the volume is controlled inside the IC, this did not affect the low-high variation. Customer was very happy to get back his lovely radio and I did not charge him anything as a gesture of goodwill.
Thus, two satisfactions jumped into the bag, which readjusted itself for accommodation.
This article was prepared for you by Parasuraman Subramanian from India. He is 74 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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Yogesh Panchal
July 13, 2024 at 2:32 pm
Repairing some old things are really thrilling job & specially when it complete with success.Good job! Sir
Parasuraman S
July 13, 2024 at 5:50 pm
Yes, you are right, Yogesh Bhai! Thanks!
Albert van Bemmelen
July 13, 2024 at 2:33 pm
Very nice radio repair and maintenance article Parasuraman. Although the explanation about the shorted centre pin with the hot pin that solved the crackling noises still leaves a question mark after reading?
With the following text that the volume is controlled inside the IC which does not affect the low-high variation?
Parasuraman S
July 13, 2024 at 5:56 pm
Only one end of the pot goes to the IC. The other end is grounded. When I grounded both pins, it becomes a variable resistor, which was enough for volume control in this IC. The ground potential is combined using both pins, that's all. In all probability, the pin that controls volume in the IC must be an audio signal out from the preamp that is connected to the amp section inside. Hope I am clear enough. Many thanks for your keen observation and expert comments.
PHILIP
July 16, 2024 at 11:20 pm
The radios that I used to enjoyed most to repair were the ones with the IC 2822. The IC has only 8 legs and I knew offhead the functions of the legs/pins and that made troubleshooting easy. However on a good day I would repair a radio so fast and that would make a customer fail to understand why any payment should be made at all, you know most radio and phones customers stay arround watching as you make repairs. All the same, radio repair comes with sweet memories !
Parasuraman S
July 17, 2024 at 8:27 am
The absolute truth about Radio Repair! Most of the customers do not realize that a device is repaired fast because of the inbuilt expertise! Customers do not question or hesitate to pay a doctor's fees, but expect free service from us as though they are doing us a favour by coming to us! Majority do not understand that the expertise achieved is out of toils and burning a lot of night oils! What to do! Many thanks for your interesting comments, dear!
Anwar Yunas Shiekh
July 17, 2024 at 8:59 pm
The hobby of HAM radio must have been very exciting.
Parasuraman S
July 18, 2024 at 6:25 pm
HAM radio is always very interesting, provided we have the time to participate and contribute. Thanks for your comments, dear!
Waleed Rishmawi
July 18, 2024 at 3:19 pm
these devices came to the right person to be repaired. I salute you my friend for doing this kind of job. keep up the good work and be blessed.
Parasuraman S
July 19, 2024 at 6:43 pm
Many thanks for your loving and encouraging comments, dear friend!