1959 Blaupunkt receiver capacitors -Newbie

[Omegaman]

This is my first re-cap job, and my first post to this site.

I am replacing the capacitors on my 1959 Blaupunkt 40400 receiver and I do not know how to go about selecting replacements for these capacitors.

Can anyone please advise me on what these caps are for and what I would use to replace them

Any help would be appreciated

 

[Rod Coleman]

Electrolytic [polarised] capacitors sound bad when they get old. When they get older still, they may leak corrosive fluid, or even explode. Changing them is the right thing.

4uF 350V would be expected to be for power supply stabilising. The value is not very critical. I recommend Nichicon VR series 4.7uF 450V for that position. Panasonics of many different series sound good too.

Don't use cheap unbranded or 'unknown' caps. They sound bad and have short life.

 

[Omegaman]

I used the wrong caps for the coupling capacitors

Thanks for assisting me in this endeavor

I realized I did not use 10% capacitors for the .022 450v coupling caps.

I will go and buy quality 10% 22t (.022uf) caps for the coupling caps and replace the ones I just put in with the 10% ones

I think I could put the new 4uf 450 filter caps (in the photo) underneath to preserve the original can caps look on top

 

[Frank Berry]

Don't leave the original filter caps in the circuit. Remove them.
At their age, the caps are probably not good. If they develop a short, they can damage the printed circuitry.

 

[DF96]

For audio coupling caps in a typical receiver circuit 50% tolerance would be perfectly adequate! If the original were 0.022uF then you can probably use anything from 0.01uF to 0.047uF. There would be a minor difference in bass, but you are unlikely to notice.

 

[kruesi]

Much as I admire German engineering, I have to say that caps of this vintage are most certainly dried out- I'd replace them without a second thought. I've had good luck with Nichicon- don't know if they make any 4uF 350V but I wouldn't be surprised..!

 

[es44]

I think I could put the new 4uf 450 filter caps (in the photo) underneath to preserve the original can caps look on top

If You, for "cosmetic reasons", want to preserve the look of the old capacitors, You can carefully remove the "guts" of them , and put the new capacitors in the empty shell with a small dab of hot glue.
I have seen this done in vintage radios, in most cases the new ones are physically smaller than the original.
Just my few cents.

Happy renovation.
Ebbe

 

[Omegaman]

For audio coupling caps in a typical receiver circuit 50% tolerance would be perfectly adequate! If the original were 0.022uF then you can probably use anything from 0.01uF to 0.047uF. There would be a minor difference in bass, but you are unlikely to notice.

Good news, since twice handled is twice work

I'll get those filter caps replaced today

 

[Omegaman]

Here is what I did for these can caps

I just pulled them off and soldered new caps underneath

That should work ok?

 

[costis_n]

Looks good! Just keep the polarity correct!

 

[Omegaman]

Thanks for the feed back. It REALLY helps me keep moving forward and builds my artifical confidence

I just have two more sets of capacitors that I need some advise on.

#1
These small, brown, 0,04uf 150v look like molded caps

Should I change these out?
Any idea what they are for?

I noticed on this particular capacitor set that they do not appear to match the schematic. I only see two on the schematic

Any advise on these caps would be of great help to me

#2
Capacitors C846, C847. Wierd little tiny wire tube ones and an unmatching golden one

The schematic says 12, so is that 12pf?

The picture shows the two different caps one is clearly marked C847 and the other is the gold one, Should I change to match these? What are they for?

Again please advise


These pictures show lots of oldcaps that have been changed already, so don't flame me for the electrolytics visible.thanks

 

[Omegaman]

OK I replaced the brown molded .04uf 150v with .047 250v orange dip caps

I did not change the 12pf caps. I have some 22pf caps if I need to change those

Man am I SCARED to power this up. I have been checking and rechecking my work for 3 days now.

Time to power it up TONIGHT

 

[4season]

C846 and C847 are denoted with an extra "dot" on the schematic which probably denotes the side that the outer wrapping of the capacitor is connected to. This is done to minimize noise pickup. I'm guessing that these don't need to be touched. As long as the correct value of fuse is installed (never assume!) you should be okay to power it up.

 

[es44]

Maybe it's a little too late, but i once saved this website to my favourites: UK Vintage Radio Repair and Restoration - Capacitors
It could come in handy, if You've been bitten by the "upgrade bug"😀

Edit. One more, use Google translate: http://www.py2bbs.qsl.br/capacitores.php

And this one: http://my.execpc.com/~endlr/index.html

 

[Omegaman]

I powered it up and it works! Sounds great. Nice and clear

So a newbie CAN change caps and resistors and by being careful saving money by doing it yourself

Thanks for everyone who assisted and advised me in this, my first re-cap of a tube amp

Now I am going to recap EVERYTHING

I am so happy

 

[es44]

Now I am going to recap EVERYTHING

I am so happy

Well, now You've experinced it, and there's no turning back. You are now officially ADDICTED, and there is no cure. 😀

All the best
Ebbe

 

[kruesi]

Congratulations, Omegaman!

Yes, there's no turning back at this point... It'll be in your blood forever. Fortunately there's lots of parts available and lots of help right here. -And an amazing number of resources on the web.

Happy Listening!

 

[807tubenut]

Fantastic job! Got a shot of the whole radio?



Got to find yourself a full complement of telefunken tubes now!

 

[Omegaman]

Full picture of the Blaupunkt

This is a picture from when I first unloaded the unit from my truck and was powering up the air compressor to blow the HUGH amount of dust from the chassis.

 

[kruesi]

Wow.

Do a great job on it- let your work be an upgrade to the original craftmanship- This thing is a CLASSIC an will live for a very long time with a bit of care.

Very good idea, replacing ALL the 'lytics!

You've got a real gem there- ENJOY!