telefunken jubilate S

[inecik]

hi, friends
just now, I purchased a jubilate S and, I replacemend smoothing elektrolitik capacitors and 6 paper capacitors but there is a problem, When I turn on sound potansiyometre but the sound is very low, there are a lot of station but the sound is low.

[olli0371]

Hi,

first :
Check the schematic if the chassis is directly connected to the mains ! - Some of this small radios only have the transformer for the heater circuit of the tubes - the power supply will be directly taken from the mains - then it is dangerous to handle the chassis if it is connected to the mains (risk of electric shock).

If there is no connection to the mains then try to switch the radio to 'TA' and try to connect an external source to the 'TA' connectors. If the sound level is also low then the problem has something to do with the EABC80 or EL41 (if you jubilate is this :http://www.radiomuseum.org/r/telefunken_jubilate_s.html).
Check the circuit diagrams and try to measure the plate / grid voltages and compare them with the values in circuit diagram (mainly they are mentioned there).


best reagards
Oliver

[inecik]

Hi, I have connected an external fm tuner to TA socket and also the sound level is very low.after I have checked voltages measurements
EABC80 pin 9 .....90 VDC
EL41 pin 2 .....240 VDC

[olli0371]

Hi,

seems to be ok. How about EL41 Pin 6 and pin 7 ?

regards
Oliver
Edit: Pin 5 is also point of interest.

[inecik]

Hi, EL41 pin 7 .....6,3 VDC
pin 6 .....zero

[olli0371]

These two seems to be ok.

How about Pin 5 (grid 2) ?

If this is also ok (about 250V) you can touch grid onepin 6) with a screwdriver - this should result in a hum in the speaker.

regards
Oliver

[inecik]

hi, pin5 .... 220 VDC
another idea, the potansiyometre may be faulty ?

[olli0371]

Hi,
220V g2 voltage is also ok.
I propose to check the signal from Grid 1 EL41 backwards.

If touching g1 of EL41 results in hum, then you can try to touch the middle pin of potentiometer also with the screwdriver (Bevor turn it to maximum volume. This should result in a hum much louder then touching Grid1 of EL41.

Please check this and we will see.

Regards
Oliver

[inecik]

Hi, I have touched pin 6 of EL41 with screwdriver but there is no hum.

[olli0371]

Hi ,

is it possible to connect an external speaker to the radio ? Sometimes there is a socket for an external speaker with contact to switch off the internal speaker and the contact is bad (dirt; oxidized). This results in that the built in speaker is not working properly.

If there is a socket - try to connect an external speaker.

Oliver

[inecik]

sorry but there is no a socket for external speaker, how can I check the potansiyometre?

[olli0371]

Hi,

you can check it by measuring the resistance. Before that switch off the radio and disconnect it from the mains.
Normally you can measure from the middle to the cold side (which is connected to the chassis somehow) a resistance which is adjustable about 1 MOhm maximum.
If there is no hum by touching g1 of EL41 and also no hum by touching g1 of EABC80 (if potentiometer is turned to max) the problem is not at the potentiometer. If potenziometer is interrupted it should be possible to generate hum by touching g1 of EL41 - at least by touching g1 of EABC 80.

- The EL41 should work according to the voltages measured by you
- There is absolutely no hum if you touch g1 of EL41
- The plate voltage of EABC 80 is also ok

For me this means, that there could be a problem at the secondary side of output transformer. The conenction to the speaker has a problem or the speaker itself is faulty.

Thats my idea.
Perhaps you can post a photo of the chassis and if you show a circuit diagram here we can give other hints for you.

reagrds
Oliver

[inecik]

Hi, I will try to send a copy.

[olli0371]

Hi,

check C41 (connected to tone potentiometer) or just disconnect it. If shorted the signal to grid 1 of EL41 is also shorted -> no sound.

regards
Oliver

[inecik]

Hi, on the circuit ,I haven't replacement C44 because it has 3 legs, is it faulty ?