Restoration Autovox RA15/L Car Radio for Lancia Aurelia B20

 | 28 April 2017 08:00

(If you are not reading this article from depoi.net, please read this post in full at this page)

The restoration I am about to describe is rather unusual: it doesn’t happen everyday to work on a car radio which dates back to the early ’50s, specially if made in Italy. Moreover, the radio was sent to me directly from the United States as part of the restoration of a glorious Lancia Aurelia B20 Coupé, which left the manufacturing plant in Piedmont in 1952, probably spent its early life in France or Canada (as suggested by the fact that the radio had French tubes installed) before its American registration in 1962, in Chicago, till being rescued by an overseas collector which spent 3 years to bring it back to life… well, the story well deserves to be told.

Some time ago I was contacted by an American architect and collector of historic Lancia cars, which found me through Radiomuseum and this webpage, to ask if I could help him in his restoration project of the 1952’s Lancia Aurelia B20. Restoration was nearly finished, and described in details in his web page www.lanciainfo.com, except for the original car radio, an Autovox RA15/L, which was not working and in rather poor conditions. For its restoration, the owner contacted several repairers, which all gave up after many unsuccessful attempts: last one even said that, the further he went on fixing faults, the bigger amount of new faults he was finding.
Considering that the car radio had already been sent from Chicago to some repairers in California and Wisconsin, without success, and not knowing anyone trusted that I could recommend in the US… I was initially hesitant in accepting this restoration project due to the poor conditions of the radio, I agreed to accept the challenge and to have the radio shipped to Italy via express courier.

Before talking about the restoration itself, I feel obliged to list some technical aspects of the radio:
a 6-tube superheterodyne receiver (12BA6, 12BE6, 12BA6, 12AT6, 6AQ5, 6X4) with RF amplifier stage, with three wave bands (BC and 2xSW), of course operated with 12 volt direct current:
an electromechanical inverter, known as vibrator, is used for the high-tension power supply of the anode of the tubes, transforming the direct current of the battery into alternating current, generating a square wave, together with a transformer to increase the voltage as needed.
The output current from the transformer is transformed into direct current by the rectifier tube, in order to operate the tubes. Thanks to the (square) waveform, filter capacity doesn’t need to be very big, and the filter capacitors are indeed rather small.

Tuning is done through variable inductors, operated by the left knob. Already at that time there was the feeling that distracting the driver with the manual research of the stations had to be avoided when possible: indeed, the radio has three push buttons for the selection of three pre-tuned stations. When the button is pressed, a mechanism frees the tuning device (variable inductors) from the manual tuning operated by the knob, moving the device to the position corresponding to the frequency of the pre-tuned station, including the dial pointer.

The procedure to memorize a new preset station is as follow: inside each push button there is a chromium-plated brass knob, which is embedded within the button during normal operation of the radio. When you’d like to change the radio station assigned to a preset button, you should just fully press the same push button (as if you wanted to tune the preset station) and then press the spring at the bottom of the button. The brass knob will come out, and rotating it will allow the selection of a new station at the same way as for the manual tuning. There were other version of the RA15 also for Alfa Romeo 1900 (model RA15/A) and Fiat 1400 (model RA15/C), with some differences on the front panel; similarly, other makers were also selling car radios for Aurelia, such as the Condor S5/A. In our collection we have also an Autovox RA39 autoradio for Lancia Appia, surprisingly a new-old-stock, which is also quite similar to the radio in this article.

When the parcel arrived, it was no big surprise, overall conditions were perhaps a bit worse than in the photo: the chromium-plated chassis had a lot of rust, rubber gaskets and wires were completely dried out, the thermoplastic front panel has yellowed and cracked, showing the long years the car must have been exposed to the weather and to hot summers.
The conditions of the three bush buttons below the dial was however the most worrying. The buttons, as mentioned before, are used for memorizing and quickly selecting the three preset stations: already at that time, in fact, it was deemed necessary to avoid the driver to be distracted by manually searching for the stations. All the three buttons were broken, with relevant portions missing, the plastic of one of those was even crumbled: they didn’t fall to pieces only because the internal preset mechanism was keeping them all together.

Since this issue was worrying me a lot, I decided to start working on it at first, postponing the electrical reparation, about which I was less concerned. In order to fill the gaps and fix the cracks of the plastic material, I needed a product which allowed me both to stick the pieces and the filling up. I solved using epoxy resin glue to stick the biggest parts and, in order to give mechanical stability to the buttons, I filled the gaps and replaced missing parts using two-component plastic reinforced by incorporated fiberglass, bought in a local paint shop in Udine (I). The colour of the preparation was adjusted with some pigments found in the same shop. Once everything dried up, I polished the buttons until I reached the aspect shown in the photos: the reparation can be seen only from very short distance. The buttons were stable, sturdy and perfectly working, so they could be put back in their place.

I could then continue with the electrical restoration: at first, I verified that the set was complete and the continuity of the wiring; basically, there were no damages done by previous repairers, but all the connections (power supply, loudspeaker, antenna, etc.) had been cut, so at first I had to restore the wiring, not very easy even following the schematic.
During this task I could notice a technical sophistication: a negative feedback which is carrying part of the signal from the loudspeaker to the pre-amplifier tube.

Main critical parts, such as the electrolytic (filter) capacitors and coupling and decoupling capacitors, had already been replaced during previous attempts of restoration, which made my task somehow easier, and so that I decided to power up the car radio.
For this purpose, since I had no power supply which was able to provide such an high electric current, I had to build one starting from a common PC switching power supply, which I modified accordingly (on request I can give further details of the modification).

The tubes immediately powered up with a beautiful red-orange colour, but unfortunately nothing was coming out from the loudspeaker.

Verifying the anode, I noted that there was no voltage, so I went on checking the asynchronous vibrator which, I felt, was way too quiet… I verified the continuity with a ohmeter, which showed an open-circuit, despite the coil was in good working conditions (indeed, I could hear it being promptly triggered when I supplied the 12 volt). Probably the contacts were faulty, worn out after long years of usage.
I decided to try a quick and dirty fix, in order to be able to use it and to test the radio, at least temporarily, until I could find a spare part.
I managed to open the vibrator, forcing the aluminium bottom: the interior was completely insulated with foam caoutchouc rubber, whose strong smell of old rubber nearly dazed me. After polishing the contact with sandpaper and adjusting the distance between the electrodes, I could successfully test it and so it could be resealed. In the meanwhile, I ordered a solid state vibrator from a well-known American website which, once arrived, would have been definitely a very good replacement.

Once the fixed vibrator was put back in place, the radio immediately showed its strong voice and its selectivity and sensitivity. At this point most of the difficult part was done: I attempted to align the intermediate frequencies, but it was impossible since the ferromagnetic cores were factory sealed with paint. Last task was a small fix on the tuning mechanism, which was defective due to a broken bakelite cylinder of the tuning coils: at the end of the dial, the magnetic core of the variable inductor was falling down, and had to be manually put back in position each time. Once fixed, I lubricated the mechanism, polished the chassis with Metalcrom (an Italian product to polish metal surfaces) and the plastic parts with some specific wax. To complete the work, I memorized the three preset stations according to the owner’s preferences (in the United States there is a vast selection of standard broadcast stations), and the radio was ready to be shipped to the owner, to the other side of the Ocean, to rejoin its old companion of many trips across the roads of the Old and the New World.


(photos of the car by courtesy of Geoffrey, www.lanciainfo.com)

We thank the website Viva Lancia for the kind review of this article.

Blaupunkt Frankfurt car radio restoration for Jaguar E-Type

 | 15 April 2017 08:00

Jaguar E-TypeI have been recently contacted by a vintage car collector, which was attempting to restore a prestigious Jaguar E-Type Coupe, to ask if I could repair its car radio.

The car radio was a Blaupunkt Frankfurt, dated 1967/68, which the car was equipped with.
Both the car and the radio had American origin, but the car radio was purchased separately, since it came from the stripping of another vehicle.

Just arrived The car radio is already a fully transistorized device, and it is a classical Blaupunkt receiver for standard broadcast, short waves and frequency modulation bands.
It has five push buttons for the mechanical selection of the pre-tuned stations: two AM, one shortwave and two FM stations.
As mentioned, the radio has an American origin, as shown by English acronyms of the wave bands and by the fact that the FM band was spread up to 108 MHz, whereas most European FM radios of that time were reaching only 100-101 MHz.
Correct identification of the model can be difficult, since the name Frankfurt name was shared with dozens of other models from different decades and with different technologies, which means that we have to rely on the chassis number usually printed on paper labels on the case of the radio. This is common for the production of this manufacturer: often a name of German city (München, Bremen, Stuttgart, Hamburg, Hannover, Köln, Ulm, Wolfsburg, Berlin, Essen, Mannheim, Hildesheim, Heidelberg, Emden, Dortmund, Karlsruhe, Solingen, Wiesbaden, Braunschweig, Koblenz, Marburg, Fulda, Flensburg, Minden, Bamberg, Coburg, Goslar, Ludwigshafen, Lübeck, Münster, Bonn, Ingolstadt, Kiel, Konstanz, Tempelhof, Göttingen, Mainz, Limburg, Nürnberg, etc.) or foreign (Vienna, Toronto, New Yorker, Montreal, Colmar, Lyon, Calvi, Lille, Le Mans, Windsor, Porto, Verona, San Remo, etc.), together with a numeric code.

Concerning the conditions of the radio, those were rather good aesthetically, but it could not be tested since the potentiometer of the volume control (which served as power switch, too) was broken.
The cause of the damage is easily guessed from the brute force evidence on the plastic knob still attached on the ‘stump’ of the shaft: since both the shaft and the bushing are made by aluminium alloy (or maybe even Zamak), they seized up because of oxidation. Taking off of the knob was therefore impossible, preventing the removal of the radio from the dashboard.

Inside, as arrived Inside, as arrived Details broken potentiometer

The ‘dismantler’ decided to use violence against the poor knob, breaking the pin. After further examining the conditions of the potentiometer, which was heavily deformed, I noticed that the damages continued even inside the radio, where some PCB pads were delaminated.

Broken potentiometer broken potentiometer broken potentiometer    details broken potentiometer

Unfortunately these Blaupunkt potentiometers (branded “Ruwido”) were practically custom-made for each of these radio models, and it is nearly impossible to find an exact replacement. Indeed, the potentiometer has a non-standard shape, and it fits not only the power switch, but also the balance control; and there are some intermediate pins along the resistance element, being an audio taper potentiometer. In conclusion, this was really a problem.

After some time, I went to one of the local electronics seasonal fairs, where I could find Pot. originale smontato some Blaupunkt potentiometers very similar to this. Once back at home, I could verify that only one was mechanically similar, but still not compatible, not only because of the displacement of the pins which was different from the holes in the PCB, but also for the resistance values.

With patience of Job (note the teutonic maniacality and the enormous number of small pieces with which it was produced!), I dismantled both the old and the new potentiometers and transferred the resistive elements of the old one onto the new one. I also kept the switch of the new one. I finally adapted the mechanical parts with a metal file.

A friend with a lathe helped reproducing the black plastic knob.

Rebuilt know and potentiometer Rebuilt know and potentiometer

The radio also had a faulty connection in the wave band selector, which was easily solved with some soldering.

Dismantled power unit  Detail reparation Detail reparation of faulty connection on the wave band selecotr

Fixed the faulty connection, the radio was still perfectly in order and well aligned, so the restoration work was finally concluded.

Blaupunkt Frankfurt car radio for Jaguar E-Type

Radio Phonola 563 Castiglioni Restoration

 | 15 March 2017 08:00

In this post I describe the restoration of a Phonola 563 radio.
For our non-Italian readers, this is one of the most famous examples of Italian industrial design, as it shares the design with the earlier model 547. This model was designed by some of the best known architects of the 19th century: Luigi Caccia Dominioni, Livio e Pier Giacomo Castiglioni. For this reason, radio collectors often refer to Phonola 547 and 563 with the nickname “Phonola Castiglioni“. These radios are often found in many design books and museums of design and modern arts.

Radio Phonola 563 "Castiglioni"

The radio of this article was rather tampered, both mechanically and electrically. In its long life, the radio has been repainted, but someone also decided to strip the paint off leaving several scratches and marks on the bakelite case. One of the push buttons (for the selection of the pre-tuned stations) was missing, as well as the tuning dial (replaced by painted cardboard), the dial pointer, the celluloid cover of the dial.


Conditions of the internal part were far worse. For instance, the support for the loudspeaker and the power transformer was missing, and the transformer was able to move almost freely in the case. Original loudspeaker was not original, replaced by a part from an American radio, what’s more nearly without its cone. This was loose as well: most likely, the original loudspeaker was out of order and some repairer found a spare part with a similar diameter and same speaker impedance, but with slightly different overall dimensions, so that he was forced to remove the prop holding the old speaker up, leaving both speaker and transformer without their support.
I have rebuilt a new aluminium support to which I could fix the transformer and, once reparation is completed, the speaker. As a replacement for the non-original speaker in poor conditions, I installed a speaker with same diameter from another radio.


Moreover, another former repairer, obviously frightened of the complexity of the circuit, came to the idea of simplifying everything removing several capacitors and resistances which were situated in the area between the sockets of the four octal tubes. Following the schematic diagram, I was able to rebuild the circuit that has been tampered with, using new reliable parts. On top of it, someone removed also the two inductors in a series circuit with the power supply, which allowed the radio to work without an external antenna, using the one side of the mains as source of the signal: most likely one of the capacitors connected to the live mains suffered an electrical short, which literally made the two coils to go up in smoke.

The tuning dial cord string also needed replacement. This radio was rather compact for its age, which meant more complexity. Replacing the cord took at least two hours and a half of swearing 🙂

The wave band selector switch was missing the small ball which allows triggering, and was not aligned with the push buttons – this was however quite an easy fix.

After the circuit was rebuilt, I tried to power up the radio – of course, nothing happened. I cleaned the power switch which was malfunctioning and attempted again: only three tubes out of five lit. Tube tester’s response showed a failure of the two tubes, which had open filaments. Once the tubes were replaced, the radio started humming and, injecting an audio-frequency signal in the audio output circuit, the signal came out through loud and clear, so the work previously done was correct and I had to shift my attention farther upstream. Unfortunately the radio part was still silent, and here started a laborious process of diagnose so many faults that it really seemed a Sisyphus’ work. The four intermediate frequency transformers were all completely out of alignment due to the failure of the Mica capacitors, common problem of any Phonola tube radio of this age.
I’ve connected new capacitors in parallel with the out of order ones, and after repairing and aligning the IF stage at 470 kHz with a lot of efforts, radio was still not working, although it was receiving some noises, which meant that much has been done (at least I thought so…).

Then I took a capacitance meter and tested all the Mica capacitors in the radio frequency stage: one was out of order. After its replacement, the radio:
– could receive shortwaves very well but with low volume, and
– could receive standard broadcast strongly but with feedback squealing and howling between the various stations.
Regarding SW bands, the problem was due to an open circuit in the aerial coil, probably caused by a short between aerial and mains. Once repaired, the radio started to receive shortwave bands very well.

Fixing the reception of standard broadcast wasn’t as easy as for shortwave bands. I verified, with the voltage table, that they were in order, so that the reason of the squealing noise was one of the Mica capacitors of the oscillator, that I had replaced previously but, following the schematic of the similar Phonola 547 (I could not find the schematic for the 563), with one with a different value. After a further check, voltages, alignment and everything else were finally in order, radio was finally working perfectly… until one of the ill-famed Phonola intermediate frequency transformers, even if after my controls and alignment, went again out of order: one of Mica capacitors decided to change capacitance without an apparent reason, causing the tuned circuit to go out of resonant frequency.

Verified once more the complete and reliable operation of the radio, I fixed the speaker to the rebuilt aluminium support.

Accurate reproductions were made for the missing push buttons, the dial and the cover of the dial. Should anyone need it, I attach a scan of the reproduction tuning dial. The dial pointer has been redone with a stiff copper wire which I painted black.

This is the final result:

AMC 3235647 and 3238861 Car Radios Restoration

 | 17 February 2017 17:08

Some time ago I’ve received an inquiry for repairing a couple of car radios for AMC vehicles.

For our European readers, it might be beneficial to remind that AMC, American Motors Corporation, was the automobile company which owned the iconic Jeep brand across ’70s and 80s, before its sale to Chrysler.

The two car radios were standard AM/FM stereo, but with a citizen band (CB) transceiver. They were sold specifically for the Jeep Grand Wagoneer, CJ-5/7/8, Scrambler and Pickup at the end of the Seventies and at the beginning of the Eighties.

I was told in both cases that the car radios weren’t able to receive any FM station, only humming, whilst AM and CB bands were working fine.

These radio can be identified via the part number AMC 3235647 (I also saw a nearly identical with part no. AMC 3231848 as well as an AM-only radio with CB, AMC 3231847, and an AM/FM radio without CB, AMC 3240714), and were made in Japan by Mitsubishi Electric Corp. Later models, such as AM/FM 7700776578 and 8956001282, were still made in Japan, and some newer ones (such as the AM/FM 8936001127 and 8956001843) in Singapore.
AMC car radio of the 60s and 70s were manufactured by Motorola in US, instead.


I was initially hesitant in accepting this restoration project since I couldn’t find any documentation about these models or similar Mitsubishi radios: it can be very difficult and challenging to work on these sets without service manuals or schematics.

At first, I asked the owners to make sure that there was no mechanical fault: when turning the knob, the dial pointer was moving correctly across the broadcast dial.

Moreover, since the radios have a CB transceiver, it might have been damaged if someone tried it without connecting an antenna or a dummy load.

As soon as I received the radios, I was able to verify that they were working properly in AM indeed. AM and FM circuits are separated: the AM one is transistorized, like a common pocket radio, while the FM one is using two integrated circuits; the second IC (stereo FM decoder) seemed to be working, whereas I had serious doubts about the first, a Mitsubishi integrated circuit (IF amplifier, FM demodulator).

As previously mentioned, it can be very complicated to troubleshoot this kind of devices without any service manual or schematic diagrams. Even for the Mitsubishi integrated circuit, nearly no information is available on the Internet: only a description of the pins, no data-sheet at all. Confidentiality must have been an important corporate value at Mitsubishi at that time!


I could verify, injecting a signal, that the IF signal (intermediate frequency of a super-heterodyne receiver) was present as input to the IC and that it was altering when turning the tuning know (which meant that front-end and oscillator stages were working, and the radio was receiving the FM signal), but the output signal was completely flat-lined.

Moreover, the output voltage was 2 volt only: for a vintage device, this voltage was clearly too low to allow the internal IF amplifier working. The fault was certainly identified in this IC.

I ordered the spare parts from a British seller, and after the replacement of the faulty integrated circuits, both radios were able to properly work in FM, too.
As per regular maintenance, I lubricated the potentiometers, checked the continuity of all the cables (including the cable of the microphone) and verified that all wave bands (including AM and CB) were receiving correctly. Also FM Stereo was in order, as shown by the green LED on the left: the stereo decoder works only if it receives the 19 KHz embedded in the low frequency audio signal.

In this short video we can see it working.

Regarding the test for the CB, the last part of the video shows what happen when you transmit: when you push the button on the microphone, you can see the carrier wave on the oscilloscope. The amplitude is about 20 volts on 50 ohm load which means 8W peak or 4Wrms – which is the legal limit for CB transmission. When speaking in the microphone, it was possible to see the amplitude modulation on the carrier wave, and the depth of modulation was very good. This was a good news because the transmitter was working properly. I checked the frequency accuracy with my HP 5246L spectrum analyzer (in the below photo, the frequency of channel 40):

Frequency accuracy - HP 5246L

On the receiver point of view, it also worked but there were faulty contacts on the channel selector switch which had to be cleaned with a deox spray.

Only few days afterwards, I was contacted for repairing another AMC car radio, part number 3238861, more or less contemporary of the previous 3235647, with a cassette player but without CB. It was also made in Japan by Mitsubishi for Jeep vehicles.

AMC 3238861 autoradioCoincidence, also this radio wasn’t not working in FM. On top of this, cassette player had mechanical problems, and the pivot pin of the volume was warped.
The fault was due to a faulty IC in this case, too. After its replacement, the radio was working again. After the bent pin of the volume and the cassette player were fixed, also this car radio was ready for be reinstalled in its old companion, an iconic Jeep.

FIAR history

 | 18 March 2006 21:49

ALESSANDRO,BEFORE YOU WERE BORN I WAS DIRECTOR OF MARKETING FOR FIAR COMMERCIAL WHICH MANUFACTURED CGE, TELEFUNKEN AND SINGER RADIOS AT VIA G B GRASSI 98, MILANO. DO YOU HAVE ANY INFO AS TO THE LATER HISTORY OF THIS FACTORY AND THE COMMERCIAL FORTUNES OF THE CGE AND TELEFUNKEN BRANDS ON ITALY. ANY SOURCES YOU COULD DIRECT ME TO WOULD BE APPRECIATED. MANY THANKS!
R S THOMAS, WOOSTER, OHIO USA

Dear Thomas,
I have little information about this factory.
According to labor union’s archive of that time, FIAR (Fabbrica Italiana Apparecchi Radio) was established in 1941 when CGE (Compagnia Generale di Elettricità – Milano) bought FAR (Fabbrica Apparecchi Radio).

FIAR has been manufacturing mainly radios during the 40s, whereas it started diversifying productions in the 50s: military industry, TV repeaters for Italian public broadcasting service, electro-optics, space and aviation.

FIAR was taken over by CGE in 1967, and became CGE’s Electronics Department, with factories in Milan and Baranzate.

During the 70s, FIAR suffered a company shake-up, it has been floated again as stock company controlled by CGE; 400 workers were laid off temporarily.

In 1980 the investment trust company Setemer (Società elettrotelefonica meridionale, Ericsson group) bought FIAR. Soon after, the upswing of productions, investments and employment. The company was splitted in 3 departments: defence, space and automation, logistics. It soon became the Italian leading manufacturer of radar and IRST (Infrared Search and Track).
In 2003 FIAR S.p.A. was bought by Galileo Avionica (now Selex ES, Finmeccanica Group), and the brand FIAR seems to be no longer used.