Philips D58AU

This "Recent Repair" was kindly contributed by Seth Pittham.


Introduction

This was an interesting one (it certainly is - Paul).

Some time ago, a friend gave me a Philips wireless to have a look at. The set was a pre-war, only just, model D58AU. Quite a substantial set and probably cost quite a pretty penny when new. Motorised tuning, push button pre selectors, fold down tuning scale etc. It was obvious that the set was not originally for UK as all the markings were for France / Holland.

The set was in a sorry state. Although all complete, there must have been inhabited at one stage, as some of the exposed wiring had been eaten away. However, the underside of the chassis was remarkably clean. According to the friend, the set had been found in an old disused barn in France. He had come across the barn whilst looking at properties to buy, and being nosy, had been rummaging around when he found the set tucked away in a corner quite well hidden. Obviously not quite well enough.


The Repair

I checked over the set and replaced the electrolytics and some paper capacitors that were reading 200K ohm. All the typical Philips problem capacitors, including the ones around the motor for the tuning system. I suppose you cannot grumble after 50-60 years.

I turned my attention to what I thought should be the O/P valve. Something seemed to be amiss here. What should have been an AL2 or AL4, seemed to have been replaced with what looked like a RF pentode of some kind with a top cap. The O/P transformer was disconnected and some sort of resistive load in its place. Across the load was a couple of thin wires twisted to each side of the resistor which then went off to two small banana sockets left floating. This puzzled me for a while. Why would someone make this kind of bodge? Whatever the socket was to connect to would have been at HT potential! Luckily, I had a AL2, so went about fitting it and putting the wiring back to what I thought it should be. The O/P transformer seemed to be okay as far as the AVO said.

So, stand back, measure the HT and wind the set up on the variac. Up came the dial lamps, heaters, followed shortly by 250 volts HT, nothing much else. I pushed one of the pre selector buttons on the front of the set and saw another lamp come on somewhere else. This was followed by a loud pop and smoke. I had not seen an old 0.1 uf capacitor hiding. This was replaced and the tuning motor made a brave attempt to retune the set to a pre-set position. A tussle with the wave change produced a crackle and Radio 4 Long wave came blasting through producing a cloud of dust from the speaker cone. The magic eye was just about visible using an image intensifier. With a few more capacitors, the set worked on Medium and Short wavebands and sounded good. I was still intrigued with the strange modification however.


The Answer!

Following a conversation with a friend, who has many more years under his belt than I, we came up with the explanation.

During the war, the Germans, in occupied countries, did not permit radio receivers that could be tuned and/or receive stations other than those that they dictated. It was standard practice that wireless sets would have had the valves smashed or output valves removed by the German soldiers when they came across these sets. If you were caught with a set that was found to be in good order, you were in trouble. So, people with a little bit of knowledge would replace output valves with whatever valve they could lay their hands on, modify the circuit to produce as much output as possible and if that was not enough, connect headphones. That explained the sockets!

I went back to my friend who found the set and related the story. To my amazement he said;  "Ah, that's interesting because there was a rusty pair of headphones in a bag beside the set. They were so rusty and the wires had all rotted away, I left them behind".

I wonder how many members of the French resistance movement sat, huddled around the wireless, listening to broadcasts from Britain and other places, wondering what was going to happen and what the future held for them? I expect the set could tell some stories.


Text Copyright © 2001 Seth Pittham




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Last updated 14th April 2006.