Réela Radio Dauphin "7 Luxe"

[Station X]

On reading through the whole thread I see that mains has already been connected to the set, resulting in the valves lighting up and mains hum from the speaker. This would tend to indicate that all the mains transformer windings have continuity. They could have short-circuited turns though.

As previously suggested by another contributor to the thread, remove the valves and apply mains power via a test lamp. Be prepared to switch off if the transformer shows signs of over heating. If it stays cool, try again without the test lamp.

If all is OK, you can replace the valves, starting with just the rectifier. Use the test lamp again. If the transformer now gets hot suspect the smoothing caps. After turning off feel them to see if they're warm, taking care not to touch the terminals.

In fact if you connect your meter on volts range across the smoothers you should see the HT voltage. On switching off, if the caps are good it will decay gradually.

[kentplums]

Hi again
Could someone clarify a coulple of points please.

There are two white tubular capacitors, one to the left of the transformer and a smaller one below right. I can find no values on these - ought they be replaced or are they likely to be OK? If to be replaced how do I find the values?

The red .02µf cap in the centre. I am assuming that this is NOT electrolytic but would like confirmation. Better safe than sorry...
thanks
R

[Herald1360]

That red cap seems to read 0.2uF rather than 0.02uF but it certainly looks like a paper type. It and those black ones are probably candidates for replacement.

The white ones look rather like early film type capacitors, Mullard "mustards" comes to mind (which should be OK) but in the absence of any definite ID, if they're anywhere where failure could be expensive, I'd replace them anyway.

[ian rose]

Hello
I do have a Reela but is has no name or number on it. I could not get hold of a schematic but did restore it so I might be able to help.
How about a photo?

[kentplums]

Originally Posted by Herald1360

That red cap seems to read 0.2uF rather than 0.02uF but it certainly looks like a paper type. It and those black ones are probably candidates for replacement.

The white ones look rather like early film type capacitors, Mullard "mustards" comes to mind (which should be OK) but in the absence of any definite ID, if they're anywhere where failure could be expensive, I'd replace them anyway.

Hi Chris
my mistake, it is 0.2µf.

As for the other two, I would certainly replace them if I knew their values.

Cheers
R

[kentplums]

Originally Posted by ian rose

Hello
I do have a Reela but is has no name or number on it. I could not get hold of a schematic but did restore it so I might be able to help.
How about a photo?

Hi
yes, it seems schematics are scarce!
Is this anything like yours?
Cheers
R

[Herald1360]

If you can say where the white capacitors are connected, it should be possible to come up with a reasonable guess at their values.

Closeup pictures may be enough if you can say which pin of which valve either of them go to.

[MotorBikeLes]

Why not assume those white capacitors are OK, and measure their capacitance value. If the measurements make sense in terms of location / typical values, then you know what to replace them with if you feel you must.
Les.

[kentplums]

Originally Posted by Herald1360

That red cap seems to read 0.2uF rather than 0.02uF but it certainly looks like a paper type. It and those black ones are probably candidates for replacement.

The white ones look rather like early film type capacitors, Mullard "mustards" comes to mind (which should be OK) but in the absence of any definite ID, if they're anywhere where failure could be expensive, I'd replace them anyway.

Whilst replacing the caps I was able to make out "20000" very faintly on the smaller (going from valve to chassis) and "0.1M" on the larger ( also valve to chassis). These numbers are very faint, but would they be in the correct region?
20000 being pf and 0.1 being µf?

Still no stations - transformer doesn't get hot even after 10 minutes and no sinister smells!
Cheers
Rory

[PJL]

No stations...Are you still using the lamp limiter?

If its still the same after you have done the caps and cleaned the wavechange switch post the anode voltage readings on here.

Do be careful as the transformer insulation to chassis may have been compromised. As suggested before, I would want to earth the chassis of that set and put in a 1A fuse.

[kentplums]

Thanks for all your comments.
I am assuming throughout all this that the valves are correct and in the correct locations. The magic eye EM34 and the EZ80 are clearly marked, but the rest could be anything.
The valves are listed elsewhere in this order: EF89, ECH81,EF89, EBF89,EL84 and EZ80. Would this be as simple as left to right from above, which I think would figure (excluding the EM34) or am I grasping at straws?

Also I have taken the outer paper cover off the transformer and the windings look very black and shiny. Not very nice. If further tests show it's had it, how would I know what to replace it with, and is a modern equivalent available or even an option?

So many questions I'm afraid
Thanks
R

[Herald1360]

It's difficult to tell for the output and rectifier from the pictures, though it should be simple enough looking at them- the rectifier will have pins 1 & 7 connected to the transformer HT winding and pin 3 connected either directly or via a low value resistor to the smoothing electrolytic.

For the rest, left to right looking into the back seems right.

[kentplums]

This is how I'm getting on:

-All valves out, test lamp does not glow - transformer does not get hot or even warm.

-Rectifier valve in, valve gets hot and transformer gets hot quickly. Lamp glows very dimly at first then brightens after a few seconds.

-All valves in - rectifier and transformer get very hot to the touch, other valves pretty cool.

-Throughout all this, slight hum and occasional crackle (which coincides with flickering of test lamp. No noise caused by switching between wavelengths and no output at all from pick-up input socket.

All electrolytics changed and other caps replaced.

Where now?
Thanks for your time everybody.
R

[julie_m]

If the transformer is getting hot, that would suggest shorted turns; except that shorted turns would cause it to get hot even with no rectifier fitted. So maybe it's the main reservoir / smoothing can.

You say you replaced all the electrolytics. Did this include the reservoir and smoothing capacitors? Are you sure you got the replacements the right way around? What is the DC voltage at the positive terminal of each capacitor? (Negative terminal of meter to chassis, and select highest DC voltage range.) Time how long it takes to die away to nothing on switching off. (N.B. Do these tests with only the rectifier fitted.)

Crackling accompanied by flickering of the series lamp suggests a poor connection somewhere in the power supply circuitry (transformer / voltage selector, rectifier and reservoir / smoothing capacitors).

[Herald1360]

Originally Posted by ajs_derby

If the transformer is getting hot, that would suggest shorted turns; except that shorted turns would cause it to get hot even with no rectifier fitted. So maybe it's the main reservoir / smoothing can.

This would be consistent with bulb glows dimly at first then brightens up- presumably as the rectifier starts to conduct.

[kentplums]

Thanks Chris and AJS

voltage at 16 µf caps is 160v (+ to rectifier) and 40v (the other!). I have replaced with polarity as per originals (assuming they were original). It is difficult without the schematics/service sheets - I've been spoilt so far!
R

[kentplums]

Should have added, there is no voltage on smoothing caps after only a few seconds...
R

[PJL]

If it had shorted turns the fault would have appeared without the valves when the voltages would be higher and more likely to result in breakdown. HOWEVER, expansion as the transformer warms up when the valves are in could still be a problem. Post #10 explains the expected behaviour.

Either you made a wiring error or more likely the fault is still present. Try with only the rectifier valve and monitoring the HT as it warms up. Pull the plug as soon as it has stabalised.

HAVE YOU EARTHED THE CHASSIS?

[julie_m]

OK, it sounds like something is pulling the HT down.

Try disconnecting the resistor which sits between the two capacitors, and then apply power. Now there is only one place to measure, of course. What voltage do you get this time? Does it take longer to decay when switched off?

Carefully remove the rectifier, set your meter to its highest AC range; and measure the voltages between pin 1 of the valveholder and chassis, and between pin 7 of the valveholder and chassis. What readings do you get?

[kentplums]

Originally Posted by ajs_derby

OK, it sounds like something is pulling the HT down.

Try disconnecting the resistor which sits between the two capacitors, and then apply power. Now there is only one place to measure, of course. What voltage do you get this time? Does it take longer to decay when switched off?

Carefully remove the rectifier, set your meter to its highest AC range; and measure the voltages between pin 1 of the valveholder and chassis, and between pin 7 of the valveholder and chassis. What readings do you get?

Thanks AJS

Pin 1 to chassis: 0v
Pin 7 to chassis: 350v

Will check voltage without resistor asap
Cheers
R