For some unknown reason the mid-60's Philips radios made for the French market are quite different to ones made for export. For one thing they have a little nice design style, but they use the narrow prone to go faulty inverse cone type speaker that the French radios use a lot, I suppose they were home designed. The other major difference is with the circuit design with both positive an negative voltage rails drawn at the bottom of the circuit diagrams and in the case of this one all the bases of the transistors tied to a 1.5 volt negative bias and separate battery to supply that, harping back to the grid bias battery for valve grids of days of old.
This model only using 6 transistors, 3 in the audio and 3 in the RF, nearly half the circuit diagram is taken up with the band switching and tuning coils arrangements. The set came to me from a French seller, and I must say I was very impressed with the 3 day delivery he gave me, most people in France I've dealt with in the past have been that slow to post and even to communicate with you, that I nearly ave up on the area. America has impossible postage and import tax's now that I've stopped buying from there.
The repair
After putting in a 1.5v and modifying the 2 x 4.5v torch battery's (still available be quite expensive) to take a PP3, it made noises! All the stations I tuned into had no modulation, it was if transmitters were on but nobody was at home. This suggested a mixer/oscillator type fault. I always have a good look around for physical damage, and true enough I found a break in the earth wiring to the tuning capacitor, it looks like perhaps the band switch lever/gears had caught the wire and broke it off? A link was soldered where the gap was showing and we had life in the old boy again, "but not as we know it Jim" as the line went in Star Trek series.
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| 1, shows the break point in the oscillator circuit, 2, shows a lever that had fallen free from the car aerial socket and the other arrow showing the vertically mounted bias battery box. |
Distorted sound at different levels is a sort of sound that only experience will tell you the the speaker cone is rubbing, and as most of the flat types have given me grief in the past I soon zoomed in on the problem. The trouble is because this design doesn't allow for a magnet at the rear of the speaker, modern later types won't fit. The fix is either fit a drastically smaller one or 'frig it' is the old term used in the television repair trade, meaning do a hit and run repair. When the speaker cone rubs on the magnet it is because the mounting has become distorted and if the push the canvas of the speaker from the rear in different place you can eventually find a point that stops it rubbing, in the old days a cigarette packet would be stuck inside to hold it there in that position. Trouble being that after a while all the vibration of the speaker will shake it loose. The trick I did today was to put a small rubber bung that less likely to move in the troublesome spot. It may take a few corrections to get it right, but success can be achieved for the medium term. I also applied the usual switch cleaner to both the car aerial switch and the band switch, the car aerial switch had come loose and I refitted the spring loaded lever.
Cosmetic repairs
Not a huge amount of damage here considering the age, the plastic was a little scuffed on the front, I used plastic cleaner on that, the knobs I removed the human DNA from the grooves with a tooth brush and a cleaner. Usual white drips of paint (left over when people decorate homes) removed from the cabinet. A small amount of oil to the loop aerial hinges, this is used for Short Wave reception only and swings up from the rear over the top, only Philips experimented with this idea but is quite good. All-in-all quite a quick and satisfying repair, I have a soft spot for part red radios.
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