Dir Koen!

It is ok to write in English, many members understand it.
We have a few specialists who know the automatic and how to service it.

Andreas

Hi Koen,

in order to help you, you have to specify the malfunction of the automatic.
Then we will see, what we can do for you.

Best regards, Dieter

Hello, the automatic stop only at strong stations?
Are the other 10 Station to weak, so that the automatic holding?
Check the Magic Eye.

Greetings Markus

In this Freiburg there's a potentiometer in the back of the chassis. It regulates cut-off voltage for automatic search. Ideally you should set it as in the instructions (set P5 to zero Ohm, connect generator with 15V to points X and Y and then set it so the automatic is set off). But if you don't have generator you should slightly correct its position so automatic is more sensitive. Otherwise voltage from weaker radio stations is too low to overcome bias voltage of electromagnetic switch (EABC80).

Hello Koen,

receiving 14 stations with the EM34 by 100% closed and additional 9 stations who give 80% means everything is definitely fine with your FM reception. Don't touch the FM Box! Obviously the sensitivy of the automatic section is insufficient. The task is now to find out why. A first step could be to check the voltages supplied, first of all V1 and V2 (see schematics) and the resistors between V1 and grid of the ECL 80 triode. And report.

Regards, Stefan

Hello Koen,


the voltages you measured are not neccessarily to high. Remember you are dealing with a set from 1954! Note that the voltages given in the schematics had been measured, it is mentioned in the documents, with a "Multavi II" instrument which has an internal resistance of only 333 Ohms per voltage on range. That means to you, to measure voltages between 6 and 30 Volts (e.g. the 12 Volts at the 25k), you have to connect a 10kOhms resistor PARALLEL to you modern meter, and for measurements below 6Volts (e.g. the 3,5Volts) use a 2kOhms. The results you get now are comparable to the voltages given in the schematics.

Regards,
Stefan

Hello Koen,

before you take further steps , you make the ratio voltage at 80 % deflection of the magic eye measure . If this is > 15V , is the shutdown of automatic beyond their tolerance.
The switch-off is determined by the demodulated negatively directed IF voltage and a positive- adjustable back tension .
For this the following SB -neck : Here all marked resistances should be checked . For forcibly increasing the switch-off level, a resistor may e.g. 220k are inserted before P1.

Hello Koen ,

"SB -neck " I mean diagram segment . The word also seemed strange that has the Translator so disfigured .
The 220k resistor I have drawn in the diagram to the left of the line , in which it should be inserted .
You have not yet been notified , what is the ratio voltage at 80 % display of magic eye . This decides whether the termination sensitivity is outside the specified limits.


Hallo Koen,

mit „SB-neck“ meine ich Schaltbildausschnitt. Das Wort kam mir auch seltsam vor, das hat der Translator so entstellt.
Den 220k Widerstand habe ich im Schaltbild links neben der Leitung eingezeichnet, in welche er eingefügt werden sollte.
Du hast noch nicht mitgeteilt, wie hoch die Ratio-Spannung bei 80% Anzeige des Magischen Auges ist. Dies entscheidet, ob die Abschaltempfindlichkeit außerhalb der vorgegeben Grenzen liegt.

Hallo Peter /sagnix)

Hast Du schon einmal bedacht, dass zur Zeit in der das Radio
entstand das Raster der UKW-Sender 300Khz betrug, heute gelten 100Khz als
Mindestwert und 50khz nicht unüblich. Mit diesem Raster
hatten und haben moderne Suchlaufelektroniken, die nur eine +/- Kennung
verwenden Problem und fangen nicht jeden Sender. Wir haben ab 1980 neben
+/- , sowie maxinale Feldstärke, bei jedem Suchaufschritt von 50Khz oder gar 25 khz mit einem internen Zähler
gemessen, haben wir 10,7 Mhz ( oder die jeweilige Kennfrequenz der Ker-Filter) oder nicht ? Daraufhin stoppte der Suchlauf oder setzte den Suchlauf
solange fort, bis der Zähler sein o.k. gab. Ich glaube daher nicht, das ein FB 3DS jeden Sender der dicht bei dicht im 100khz Raster
liegt,.erkennen kann. Lass dir doch eine genaue Tabelle geben oder jede Frequenz der Sender geben die nicht erkannt wird. Wichtig sind die Nachbarsender +/- dazu.

Wer das nicht für realistisch hält (mindestens einer) braucht es nicht lesen oder ist eben schlauer als manch anderer. z.B. (decoder) Hans

GOOGLe:
Have you ever considered that the time in the Radio
was the pattern of the FM station was 300kHz, today 100Khz deemed
Minimum value and 50khz not uncommon. This grid
had and have modern scanning electronics that only a +/- identifier
use problem and not catch any channels. We have 1980 next
+/-, And maxi-dimensional field strength at each Suchaufschritt of 50Khz or even 25 kHz with an internal counter
measured, we have 10.7 Mhz (or the respective characteristic frequency of Ker-filter) or not? Then stopped the search or put the search
while continuing until its counter o.k. gave. I therefore do not think that a FB 3DS each transmitter the cheek by jowl in 100khz grid
is, can .erkennen. Let you nevertheless give an exact table or each frequency of the transmitter type which is not recognized. Important are the neighboring stations to +/-.


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