Blaupunkt Frankfurt Serial: K150607 tube layout

Hello,

Please reference this page (click link).

To follow my question, search on the serial number: "K150607"

The photos show the chassis without tubes.

Does anyone know which tubes go in which socket?

I have labeled them so I can replace the tubes, but my main problem is that the numbering on the tube itself has worn off, so I do not know which type of tube goes where.

I plan to test the tubes today, and if I find a bad one, I will not know which type to replace it with.

Now (hopefully) you know my problem.

Thanks,

Jeff

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

Hello Jeff,

I don't understand your problem. The tube layout is next to the chassis photo. In the list under the pictures you find the tubes and its US types.

Regards,

Heribert

• Blaupunkt_Frankfurt_tubes (31 KB)

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

Heribert,

Thank you. I was looking at the diagram the wrong way.

Jeff

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

More questions:

My Frankfurt has a serial number: K150607. Does that make it a "K Series" system?

I see other "Serie R", "Serie M", "Serie S" on the Frankfurt model page.

So, is my radio a "Serie K"?

How close will my radio be to the one we are linked to in this post? This radio is called "Frankfurt [neu]"

The push-buttons are the same (U U M M L) and the tubes are almost the same, but my radio does not have an EL84 - unless the EL84 is in the power supply.

Can I use the schematic for the radio shown here, or is there a better one for my radio?

Thank you,

Jeff

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

I have narrowed the problem down to the area near pin 2 of the EL84. Here are my notes from last night...

Used the 1 kHz calibration signal tone from the B+K 1460 oscilloscope to get audio from the speaker by touching the calibration probe to pin 2 of the EL84 tube socket. However, there was no audio at the speaker when the probe was placed at pin 6 of the inter connection cable socket. A hookup wire was wrapped around pin 6 of the connector plug and the probe was in contact with the hookup wire. This meant that somewhere between pin 2 of the EL84 and pin6 of the cable connector, something was wrong.

There is a 1k ohm resistor at pin 2 of the EL84 that measured low. This condition would not have created the results found. If the resistor was low, there would have been some audio at the speaker. This was puzzling.

There is another resistor and capacitor from pin 2 of the EL84 that goes to pin 3 of the connector. The working theory is that there may be a problem with pin 6 of the inter-connecting cable shorting to ground. The next step is to check continuity between pin 2 of the EL84 and pin 6 of the connector.

Question:

Does anyone know the value of the resistor and capacitor (see attached illustration) below the 1k resistor (off pin 2 of the EL84)?

• Detail of EL84 resistors and capacitors (45 KB)

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

Hello,

Does anyone know where I can get a replacement plug? This is a 6-pin Hirschmann plug with 4 smaller pins and 2 larger pins. This is for a Blaupunkt Frankfurt (series K).

Thanks,

Jeff

• 6-pin Hirschmann plug (55 KB)

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

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