Blaupunkt F511WP

1951

Condition and performance:

	Cabinet:	90%
	Reception AM:	60%
	Reception FM:	50%
	Sound Quality AM:	70%
	Sound Quality FM:	70%
	Sound Quality P.U.:	70%

Features:

	P.U. Entrance:	Yes
	Tape Recorder Entrance:	No
	Extra Loudspeaker Output:	Yes, 7000 Ohms
	Loudness:	No
	Treble Control:	Yes
	Bass Control:	No
	Tone Register Switches:	No
	AM Bandwidth Switch or Control:	No
	Tuning Indicator:	Yes, EM11
	Build-in Antenna:	Yes, FM
	Build in Ferrite or Window Antenna:	No
	Separate AM/FM tuning:	No

Technical Specifications (Partially measured):

	Tubes:	EF80, ECH42, EBF15, EAA11, EL11, EM11.
	Wave Bands:	LW, MW, SW from 16 - 50 meters, FM from 86 - 101 MHz
	Intermediate Frequencies (IF):	473 kHz, 10.7 MHz
	Loudspeaker:	20 cm diameter, electro magnet type
	Resonance Frequency Fs:	?
	Frequency Range Power Amplifier:	?
	RMS Output Power at 4 Ohms:	4 Watts
	Cabinet:	Bake-lite, dark brown.
	Dimensions:	59 x 35 x 25.5 cm
	Mains Power Voltages:	110, 127, 220 Volts~
	Mains Power Consumption	?
	Retail Price	?

Description:

The Blaupunkt F511WP is the bigger brother of the Blaupunkt B52W.
The cirtcuit is basically the same, but the FM ratio detection is done by the EAA11.
An addition is also the EM11 tuning indicator.
Another difference is the electromagnetic type of the loudspeaker.

Repairs:

Both capacitors of 5000 pF around the AZ11 are replaced. These capacitors are replaced by 4700 pF 1000 Volts.
Reason: Both 5000 pF capacitors are exploded.
Coupling capacitor to the EL11 of 25 nF is replaced by 22 nF 630 Volts.
Reason: Leakage which results in positive grid voltage and too much withdrawn current of the EL11.
Tone control capacitor of 50 nF is replaced by 47 nF 630 Volts.
Reason: Leakage which results in damaging the tone control potentiometer.
Paper/tar capacitor of the EL11 and output transformer of 2200 pF is replaced by 4700 pF 1000 Volts.
Reason: 2200 pF is replaced in the past and doesn't meet the manufacturer specifications.
2 resistors of 30K 2 Watts to the ECH42 are replaced by 27K 2 Watts.
Reason: The screen resistor and the anode resistor to the triode of the ECH42 are burned out.
2 resistors of 1M of the EM11 are replaced by 1M 1 Watts.
Reason: Increased in value. However, the EM11 is fully dead because of the worn out phosphor layer.
Loudspeaker voice coil hits the pole plate.
Solution: Aligning the magnet. Loudspeaker is also turned 90° leftwards in the cabinet.

The AM reception isn't optimal, since the HF capacitive trimmers has lost their silver surface and need to be replaced in the future.
The FM reception is poor and need further examination.
At least, the radio can now be safely used.

Performance:

After repairing the radio, the sound quality of AM stations is OK, but on FM the sound is too dark.
Further repairs for improved reception of the broadcast stations.

Home
Back to Picture Gallery 2
Contact Kees van Dijke
Download the schematic diagram.