Grundig 2041W Sound echo - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

GreensX · 16th Jan 2016, 3:19 pm

Thanks Julie,

I was able to cut the capacitor as you said. They indeed twisted it stuck before soldering. I found a ceramic capacitor at 4,7nF / 500V. But I was wondering if it would be okay to replace an electrolytic capacitor with a ceramic one. Would this cause any problems?

http://www.conrad.be/ce/nl/product/4...--6-mm-1-stuks

Station X · 16th Jan 2016, 3:29 pm

You're very unlikely to find a ceramic capacitor with the same value as an electrolytic one.

Electrolytics were designed to get a lot of capacitance in a small package, so their values typically start at 1uF as compared to 0.5uF max for a paper capacitor.

Personally I'd have used a 4.7nF polypropylene cap.

Herald1360 · 16th Jan 2016, 3:57 pm

4.7/5nF capacitors wouldn't have been electrolytic to start with and electrolytic types would never have been used for anode-grid coupling since their leakage resistance is far too low.

Ceramic in that role will be fine- some manufacturers used it, though not commonly.

julie_m · 16th Jan 2016, 10:20 pm

Can you please confirm what the capacitor you just cut was connected to? As in, which number pin of which valve? A picture also will help.

Because if whatever you cut really was an electrolytic capacitor, that can't be the right part. At least if you only cut one lead, it will be an easy fix. On the other hand, it could have been a paper capacitor in a metal sleeve, looking a bit like an electrolytic.

GreensX · 20th Jan 2016, 2:14 pm

The capacitor I cut was a paper one, I'm sorry but i thought paper = electrolytic. The sleeve is black plastic and it said '5000 pF - 500-1500V (temp: 0°C - 70°C). I just finished soldering the ceramic one (4720pF - 500V)

Station X · 20th Jan 2016, 2:58 pm

With few exceptions you can recognise an electrolytic capacitor by the fact its value is greater than 1uF and it is polarised ie it has a positive and negative lead.

GreensX · 21st Jan 2016, 2:03 pm

The radio seems to work just fine now, just a mild crackling noise that sometimes comes and goes away. I'm probably going to replace most paper capacitors with modern ones and see how it further improves. Anyway, thanks everybody for helping me out! Couldn't have done it without your help!

16th Jan 2016, 3:19 pm	#21
GreensX Retired Dormant Member Join Date: Jan 2016 Location: Ghent, Belgium Posts: 9	Re: Grundig 2041W Sound echo Thanks Julie, I was able to cut the capacitor as you said. They indeed twisted it stuck before soldering. I found a ceramic capacitor at 4,7nF / 500V. But I was wondering if it would be okay to replace an electrolytic capacitor with a ceramic one. Would this cause any problems? http://www.conrad.be/ce/nl/product/4...--6-mm-1-stuks

16th Jan 2016, 3:29 pm	#22
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Grundig 2041W Sound echo You're very unlikely to find a ceramic capacitor with the same value as an electrolytic one. Electrolytics were designed to get a lot of capacitance in a small package, so their values typically start at 1uF as compared to 0.5uF max for a paper capacitor. Personally I'd have used a 4.7nF polypropylene cap. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

16th Jan 2016, 3:57 pm	#23
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Grundig 2041W Sound echo 4.7/5nF capacitors wouldn't have been electrolytic to start with and electrolytic types would never have been used for anode-grid coupling since their leakage resistance is far too low. Ceramic in that role will be fine- some manufacturers used it, though not commonly. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

16th Jan 2016, 10:20 pm	#24
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Grundig 2041W Sound echo Can you please confirm what the capacitor you just cut was connected to? As in, which number pin of which valve? A picture also will help. Because if whatever you cut really was an electrolytic capacitor, that can't be the right part. At least if you only cut one lead, it will be an easy fix. On the other hand, it could have been a paper capacitor in a metal sleeve, looking a bit like an electrolytic. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

20th Jan 2016, 2:14 pm	#25
GreensX Retired Dormant Member Join Date: Jan 2016 Location: Ghent, Belgium Posts: 9	Re: Grundig 2041W Sound echo The capacitor I cut was a paper one, I'm sorry but i thought paper = electrolytic. The sleeve is black plastic and it said '5000 pF - 500-1500V (temp: 0°C - 70°C). I just finished soldering the ceramic one (4720pF - 500V)

20th Jan 2016, 2:58 pm	#26
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Grundig 2041W Sound echo With few exceptions you can recognise an electrolytic capacitor by the fact its value is greater than 1uF and it is polarised ie it has a positive and negative lead. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

21st Jan 2016, 2:03 pm	#27
GreensX Retired Dormant Member Join Date: Jan 2016 Location: Ghent, Belgium Posts: 9	Re: Grundig 2041W Sound echo The radio seems to work just fine now, just a mild crackling noise that sometimes comes and goes away. I'm probably going to replace most paper capacitors with modern ones and see how it further improves. Anyway, thanks everybody for helping me out! Couldn't have done it without your help!