Blaupunkt Salvador 2575 Radio- What is this part?

Hello,

I have successfully restored the Blaupunkt  Salvador 2575 Radio, but is unable to identify this particular component, ( i do not have the Schematic ) . This is connected through Speaker, Not sure what is it and it's role in the circuit. 

If any one can help me with it's function, i will be very greatful.

Kind Regards

Uday K

• Square plate? (188 KB)

To thank the Author because you find the post helpful or well done.

Hi Uday,

this is a "high frequency speaker", modern word should be "tweeter". The parts it consists of, are made like a condenser.

Regards RS

To thank the Author because you find the post helpful or well done.

The correct term would be 'electrostatic' speaker. There are many variants. Please see the following articles (in German):

• Reparatur elektrostatischer Hochtöner (note the 4 additional links)
• Lautsprecherreparatur

I am however uncertain if your Blaupunkt part is an electrostatic tweeter, there is also the possibily of it being a crystal (piezo) speaker unit.

Kind regards
Mark

To thank the Author because you find the post helpful or well done.

Thank You Reiner and Mark, That's good, Wow they did have sort of Tweeter at that time  !. Nice, I will check the links and will know better. Thank you so much.

By the way, AM Reception is very low, when connected Aerial but SW is fine. The local Bangalore Station also comes feeble, But I saw few other Blaupunkt sets, and I see there are two sets of Aerial points, One which is noramlly connected internally with Flat white cable and the other for external. I am not sure what ever there could be another point for internal Aerial Plate, ( which is in the bottom of the cabinet), but I do not know where to solder it, in absence of schematic. Any advise?

Thanks again for your guideance.

Kind Regards

Uday K

To thank the Author because you find the post helpful or well done.

Dear Uday,

in future please please post model related questions from the model page. I assume that a moderator will move this thread to Salvador de Luxe 2575 Export.

The part in question is an electrostatic speaker, most probably type LSH75. I found same in battery operated Capri de Luxe 2572. The schematic shows that an(y) electrostatic speaker needs basically a bias voltage from +B, voltage and current limited by series resistor(s). Audio frequency is decoupled from the anode of the power tube via capacitor, followed by a highpass with resistor/capacitor combination.

To determine, remove the remaining nut and pull the speaker out. The front shall look like this:

If it looks other, please attach a foto.

By the way: Piezo (crystal) tweeters of that period are driving  a cone or membrane mechanically, so the depth is much bigger. They don't need bias voltage, but also a high pass filter. See as an example the second picture of Telefunken T5001. It is the black round plastic part left of the output transformer.

Best Regards,

Georg

To thank the Author because you find the post helpful or well done.

Dear Sir,

Thank you ! Sorry I was not knowing that I had to post question in the specific model page. I will keep it in mind. 

Thanks for the answer, Your guideance and advise is very much appriciated. The forum gives us so much knowledge !! Wow thanks to the Radiomuseum and all the Editors, Panel of Experts. 

The model is LSH75, Correct. It is in good condition

Thank you So much !

Kind Regards

Uday K

To thank the Author because you find the post helpful or well done.

Hello Uday,

Since I am forbidden to answer your contribution from the model., I have to do it that way.

Your question in this thread / post 4 was:

By the way, AM Reception is very low, when connected Aerial but SW is fine. The local Bangalore Station also comes feeble, But I saw few other Blaupunkt sets, and I see there are two sets of Aerial points, One which is noramlly connected internally with Flat white cable and the other for external. I am not sure what ever there could be another point for internal Aerial Plate, ( which is in the bottom of the cabinet), but I do not know where to solder it, in absence of schematic. Any advise?

You sent me pictures of your radio and here my attempt to help you:

I took the circuit from the Blaupunkt Flora de Luxe 2570.
This circuit should be very similar.
For medium wave, the signal is coupled via the ferrite antenna.
I hope it helps to find the right contacts.
 
Kind regards

Wolfgang Bauer

To thank the Author because you find the post helpful or well done.

Dear Sir,

Thank you So much ! I will check and hope to correct the connections as advised

Thank you again for everyone for guiding me 

Kind Regadrs

Uday K

To thank the Author because you find the post helpful or well done.