Wie herkent dit printje - hulp gevraagd. (Toestel of techniek)

door Hugo Sneyers , Tongeren, België, 17-08-2010, 11:56 (5214 dagen geleden)

Hallo radiovrienden, ik kreeg onderstaande mail maar omdat ik de oplossing ook niet weet plaats ik deze oproep hier, ik zal de afzender op de hoogte brengen dat ik zijn bericht hier geplaatst heb zodat hij de eventuele reacties ook kan lezen en ik niet telkens tussenpersoon moet spelen.

Groeten ... Hugo Sneyers:
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I have some pictures of an old audio amplifier board (see attached files), which comes very probably from a Philips device (radio, turntable...), from the 60s. I would need some help identifying it, even if I've started searching some informations about it.

Here is what I know so far ; this board has the following characteristics :

A separate audio amp board : this would indicate the device could be a turntable, or a portable car radio (from the L serie). Probably not a car radio, or a reel-to-reel recorder (everything was on a unique board).
2 transformers : a driver and an output transformer. Transformers are of the EI type. Very probably not coming from an All Transistor reel-to-reel recorder, as they were using C-core transformers.
Transformers are parallel (sometimes, they make a right angle on some Philips devices).
AC125, AC126, 2AC128, in this order : indicating very probably year 1964 for its making.
AC128s are heatsinked and attached to the transformers.
Front-end of the amp section is ground-negative. This was found in some Philips turntables (AG4257 for instance), or some Philips car portable radios of the L or P series.
Ground track all around the board, with bolts holes going through this track
Presence of metal posts : these metal posts were also found in some Philips radio audio amp boards.
All components flat on the board
Tracks are tinned : usually, tracks on Philips devices produced in the Netherlands were not tinned. Could indicate a production in Germany/Austria ? But some transistor radios from the B serie produced in the Netherlands had tinned tracks (for instance B4X52AT).
Output power : 500 mA ; this gives some indications on what kind of unit the original device was. A turntable amp would be more powerful for instance.
Output impedance : around 4 ohms.
This amp favours the human voice frequencies.
Number 022C on the board : not the usual « 12 NC codenummer » that can be found on Philips boards, but these appeared later (May 1st, 1965 I think).

What can it be ?

This unit "could" come from a Philips portable car radio. The most likely origin would be a portable car radio from the L serie.

Here are the common points between my « mysterious amp board » and the L serie portable car radio.
- A separate audio board : some radios of the L serie have a separate audio amp board.
- A ground track all around the board : this can be found on the L3W22T for instance.
- Ground-negative front end : a lot of radios of the L series were made this way.
- Bolt holes going through the ground track : also found on the L3W22T. This way, the bolts connect the ground track to a metal frame that we find in the radio (and probably to the car chassis when used as a car radio).
- Heatsinked transistors attached to the transformers : again found on the L3W22T, but also on the Babette L4D12T.
- Metal posts on the audio amp board : like on the L4X25T for instance.
- All components flat on the board : again, like on the L4X25T audio amp board.
- Output power around 500mW, like the L3xxxx serie for instance
- Tinned tracks on the PCB : radio maybe made in Austria or in Germany ? Not sure.

Of course, these are the results of my search, but it could be something completely different, such as a very specific device (intercom, etc...).

I have searched for hours and hours, but haven't found so far exactly what this board comes from. I have asked on many forums but nobody recognized it. I guess I can't find more than that using the schematics, pictures, forums, etc..., available on the Internet, and that's why I do need your help.

I'd really like to know from what device it comes from, and possibly have a service manual for it.

Thanks in advance for your help !