Dial Lamp Burning Solved In PHILIPS Valve (Tube) Radio MAESTRO 15RB677/01S
This Radio has visited me for a major work which I have reported earlier. Kindly see the link:
https://jestineyong.com/replaced-ift-with-imported-in-philips-valve-tube-radio-model-major/
This time the complaint was that the bulb gets burnt. Replacements of these types of 6.3V 150mA bulbs are no longer available in the market. Though the customer brought a few 6V 6W bulbs, it was too much a load for this Radio, as it would draw a current of 1A (Watts divided by Volts – I=P/V.) Moreover it was not thread type. So while checking what to do further by removing the sockets from its aluminium holder plate, I chanced to notice that the transformer winding was loose inside.
My multimeter was an auto-detect-auto-range type. So, it was showing resistance instead of volts when I checked. Then I removed the power and checked and found that it had intermittent contact and traced it to inside the transformer, which cannot be rectified. Just see the readings:
Then I had only two options (1) Obtain whatever was available in the market and fix a transformer for wiring it separately (2) Buy and fix a 2A transformer and fit the bulbs the customer brought. While cogitating with various ideas looking through the box containing collections of bulbs, I happened to see 15W 250V thread type bulbs with holders.
Well, then I decided to fix this in its place. Though I tried the bulb in series, the glow was not good enough. So, I enlarged the holes in the aluminium plate for a just tight fit and inserted these two bulbs and applied fixing glue covered with silicone sealant in a couple of places. Let us see the pictures of this:
Then wired these two in parallel and soldered the wires to AC input on the on/off switch under the chassis. In order not to cross the RF signal path of Rod Antenna, I pulled the wires isolating it and fixed it on the top using a drawing pin.
The work was neat and clean and the glow of the bulbs was super and the inside got illuminated very well! The light was a bit more than the original bulbs, but that only enhanced the look of this lovely set! Now let us have a look at a few more related pictures:
Mission accomplished with excellent results, which pumped more satisfactions into the storage tank, which also opened new ways of solving problems that looked like an imbroglio!
Are you all not happy to see this lovely antique Valve (Tube) Radio in this condition?
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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Albert van Bemmelen
March 22, 2025 at 3:17 pm
It is remarkable to see that most older tube radios work for so many years without getting shorted by cockroaches or other bugs. Maybe because of the bright light that distracts them from entering the device or it only seems this way? Or it is because radio tubes are almost indestructable compared to our modern low voltage easily destroyed electronic smd components?
Parasuraman S
March 22, 2025 at 4:15 pm
Mainly it could be because of the heat produced by the tubes when in use. You cannot even go near to it. But if neglected, this radio has enouch crevices for the cockroaches to hide, lay eggs and multiple many times and convert it as its haven. The failure of tubes is less compared to the modern day components. Many thanks for your expert comments and thought provoking queries!
Waleed Rishmawi
March 22, 2025 at 3:33 pm
you have revived the set and made it alive again..thank you for the detailed article..enjoyable to read. have a blessed day
Parasuraman S
March 22, 2025 at 4:16 pm
Many thanks for your support and encouragement, dear friend!
Yogesh Panchal
March 22, 2025 at 3:40 pm
Good Job! Sir
This type of repair give different joy...
Parasuraman S
March 22, 2025 at 4:16 pm
Yes, it drives us back to our youth! Many thanks, dear Yogesh Bai!
Mark J
March 23, 2025 at 3:07 am
Parasuraman another great radio repair. I always enjoy these. Thank you for sharing your knowledge and experience.
Parasuraman S
March 23, 2025 at 12:32 pm
Many thanks for your continued encouragement and appreciation, which I value very much, dear Mark!