Neat ways to mount replacement capacitors - UK Vintage Radio Repair and Restoration Discussion Forum

BakeliteBear · 27th Jul 2011, 5:23 am

Have any members got pictures of neat ways to mount modern replacement capacitors under mains smoothing electrolytics? Thanks

newlite4 · 27th Jul 2011, 9:08 am

Just mount the replacement electrolytics under the chassis leaving the originals disconnected on the surface. Modern replacements are physically smaller so can fit almost anywhere.
Neil

BakeliteBear · 27th Jul 2011, 10:11 am

But surely they need an anchor point? I thought a tag strip might be a good idea??

Radio_Dave · 27th Jul 2011, 10:25 am

IMHO emptying the old can and re-stuffing with the new capacitors is, normally, the the most satisfactory solution. All the hook up points will be in the right position and the caps will be above the chassis, where the manufactorer intended. It's really not that the difficult to do either

Regards
David

HamishBoxer · 27th Jul 2011, 10:37 am

Thats the correct answer,stuff em!Or should state restuff em.

David

HamishBoxer · 27th Jul 2011, 10:38 am

Another way to get in to the cap is saw in halve were the clamp is,this has been mentioned in a previous post on this subject.

BakeliteBear · 27th Jul 2011, 10:51 am

Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing!

I am currently minded to think it is a bit more 'honest' to do a really neat job with new components, a bit like the planners tend to think about extensions to listed buildings - show its new, but do it really well.

I could well be wrong, but I would like to see how other experienced forum members do a ‘really neat job’. If I don’t get any replies then perhaps I will get stuffing!

Station X · 27th Jul 2011, 11:14 am

If you use a tag strip you'll only need two tags, as it's safe to use the common terminal on the old cap as the third tag.

I generally restuff. Alternatively I pull the guts out of the old cap and stick it together with aluminium tape concealed by the clamp. Then the new caps can be mounted on the old cap's tags.

If you restuff bring the new capacitors' leads outside the can and wrap them round the original tags.

HamishBoxer · 27th Jul 2011, 11:29 am

Unless the set in question is very rare,restuffing provides a working set without any obvious signs.Depending how its done.

This seems to be going back on a recent thread and how vintage cars can have replacement parts and still be worth as much or more,rather than non functional and totally original.

David

HamishBoxer · 27th Jul 2011, 11:32 am

One more thing to keep appearances is to use a fibreglass brush on the joints to dull them.

60 oldjohn · 27th Jul 2011, 2:16 pm

If you are bothered about originality buy the proper caps. I bought a 50uf + 50uf new from the BVWS stall if you are not a member I think you can get them from Canada at a slightly greater cost +p&p They also stock other values. John.

Tim · 27th Jul 2011, 3:49 pm

Quote:

Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing!

Would you replace the mains cable if that was not up to scratch?

BakeliteBear · 27th Jul 2011, 10:52 pm

Quote:

Originally Posted by Tim

Quote:

Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing!

Would you replace the mains cable if that was not up to scratch?

If the set is to be used there is no choice. I don’t think all the other choices to be made are so straightforward.

The post was supposed to be about neat ways of mounting electrolytics whilst leaving the original capacitor in place.

The only point I was making was that when it is possible to mount modern replacements underneath, why rip apart the original? Stuffing components is a neat trick, and a skilful job, but I do not accept it is the only logical approach.

As with many things in life it’s all a matter of personal taste. Life would be very boring if we were all the same!

Station X · 27th Jul 2011, 10:57 pm

Tag strip for you then.

noble kiwi · 28th Jul 2011, 2:16 am

My experience shows that in the days when valve radios were bread and butter, the normal quick economical repair by the trade, involved simply fitting replacements in parallel, leaving the originals so as to provide mounting points. Nasty I know, but I have yet to come across a situation where this has in fact resulted in a short circuit and damage.

What has been the experience of others in this regard?

Station X · 28th Jul 2011, 7:52 am

Connecting a GOOD electrolytic capacitor in parallel with an existing one cannot cause a short circuit. The short circuit would need to be there before the new capacitor was connected.

My experience is that electrolytics fail to short circuit, low resistance and high leakage. Such a capacitor is likely to overheat and possibly explode if left in circuit.

If you want to connect new caps in parallel with old you need to establish that the old caps have failed to open circuit or low capacitance and that the leakage is not too low.

neon indicator · 28th Jul 2011, 9:15 am

Quote:

Originally Posted by noble kiwi

What has been the experience of others in this regard?

Removing the wreckage. Electrolytics almost always overheat and "pop" if bad and left in circuit. In the 1970s I repaired quite a few TVs & Radios "bodged" like that. It was laziness as removal of the old part was awkward in many cases.

stitch1 · 28th Jul 2011, 6:36 pm

Quote:

Originally Posted by BakeliteBear

Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing!

I am currently minded to think it is a bit more 'honest' to do a really neat job with new components, a bit like the planners tend to think about extensions to listed buildings - show its new, but do it really well.

I could well be wrong, but I would like to see how other experienced forum members do a ‘really neat job’. If I don’t get any replies then perhaps I will get stuffing!

That's what I do so I agree with you. Personally I leave cans in situ and fit new one under the chassis and other caps replaced with new ones in the same place.

BakeliteBear · 28th Jul 2011, 10:50 pm

Thanks Stitch1. Nice to know I am not alone!!

fetteler · 29th Jul 2011, 12:22 am

Quote:

Originally Posted by BakeliteBear

Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing!

I am currently minded to think it is a bit more 'honest' to do a really neat job with new components, a bit like the planners tend to think about extensions to listed buildings - show its new, but do it really well.

I could well be wrong, but I would like to see how other experienced forum members do a ‘really neat job’. If I don’t get any replies then perhaps I will get stuffing!

Firstly, nothing wrong with thinking - there's not enough of it about

Secondly, I like your parallel with listed buildings, and, having spent the last 10 years or so working on preserving ours I have to say that the best philosophy is to restore functionality and retain as much of the original as possible. For your situation with the capacitor this is easy. Leave the old one disconnected from the circuit and neatly fit a new one. Again, you've got it right (IMO) by wanting to make a neat job but not disguise the fact it's a replacement. A tag strip is probably the way to go though try to mount the tag strip on an existing screw or bolt. The old cap is a lovely record for the future - as is your repair

Thirdly, Please don't (for this particular job...) get stuffed!!!!

Fourthly, I have re-stuffed components, it's a great technique, sometimes its the best way to keep a bit of originality...

Cheers,
Steve.

27th Jul 2011, 5:23 am	#1
BakeliteBear Pentode Join Date: Feb 2008 Location: Leicestershire Posts: 204	Neat ways to mount replacement capacitors Have any members got pictures of neat ways to mount modern replacement capacitors under mains smoothing electrolytics? Thanks __________________

27th Jul 2011, 9:08 am	#2
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,806	Re: Neat ways to mount replacement capacitors Just mount the replacement electrolytics under the chassis leaving the originals disconnected on the surface. Modern replacements are physically smaller so can fit almost anywhere. Neil __________________ preserving the recent past, for the distant future.

27th Jul 2011, 10:11 am	#3
BakeliteBear Pentode Join Date: Feb 2008 Location: Leicestershire Posts: 204	Re: Neat ways to mount replacement capacitors But surely they need an anchor point? I thought a tag strip might be a good idea?? Attached Thumbnails __________________

27th Jul 2011, 10:25 am	#4
Radio_Dave Nonode Join Date: Jun 2004 Location: Norwich, Norfolk, UK. Posts: 2,543	Re: Neat ways to mount replacement capacitors IMHO emptying the old can and re-stuffing with the new capacitors is, normally, the the most satisfactory solution. All the hook up points will be in the right position and the caps will be above the chassis, where the manufactorer intended. It's really not that the difficult to do either Regards David

27th Jul 2011, 10:37 am	#5
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,935	Re: Neat ways to mount replacement capacitors Thats the correct answer,stuff em!Or should state restuff em. David

27th Jul 2011, 10:38 am	#6
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,935	Re: Neat ways to mount replacement capacitors Another way to get in to the cap is saw in halve were the clamp is,this has been mentioned in a previous post on this subject.

27th Jul 2011, 10:51 am	#7
BakeliteBear Pentode Join Date: Feb 2008 Location: Leicestershire Posts: 204	Re: Neat ways to mount replacement capacitors Ok, but does ripping all the guts out really retain ‘originality’?? I have though long and hard about this one, in fact I do a lot more thinking than doing! I am currently minded to think it is a bit more 'honest' to do a really neat job with new components, a bit like the planners tend to think about extensions to listed buildings - show its new, but do it really well. I could well be wrong, but I would like to see how other experienced forum members do a ‘really neat job’. If I don’t get any replies then perhaps I will get stuffing! __________________

27th Jul 2011, 11:14 am	#8
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Neat ways to mount replacement capacitors If you use a tag strip you'll only need two tags, as it's safe to use the common terminal on the old cap as the third tag. I generally restuff. Alternatively I pull the guts out of the old cap and stick it together with aluminium tape concealed by the clamp. Then the new caps can be mounted on the old cap's tags. If you restuff bring the new capacitors' leads outside the can and wrap them round the original tags. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Jul 2011, 11:29 am	#9
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,935	Re: Neat ways to mount replacement capacitors Unless the set in question is very rare,restuffing provides a working set without any obvious signs.Depending how its done. This seems to be going back on a recent thread and how vintage cars can have replacement parts and still be worth as much or more,rather than non functional and totally original. David

27th Jul 2011, 11:32 am	#10
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,935	Re: Neat ways to mount replacement capacitors One more thing to keep appearances is to use a fibreglass brush on the joints to dull them.

27th Jul 2011, 2:16 pm	#11
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,990	Re: Neat ways to mount replacement capacitors If you are bothered about originality buy the proper caps. I bought a 50uf + 50uf new from the BVWS stall if you are not a member I think you can get them from Canada at a slightly greater cost +p&p They also stock other values. John.

27th Jul 2011, 10:57 pm	#14
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Neat ways to mount replacement capacitors Tag strip for you then. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

28th Jul 2011, 2:16 am	#15
noble kiwi Pentode Join Date: Jan 2011 Location: Auckland New Zealand Posts: 175	Re: Neat ways to mount replacement capacitors My experience shows that in the days when valve radios were bread and butter, the normal quick economical repair by the trade, involved simply fitting replacements in parallel, leaving the originals so as to provide mounting points. Nasty I know, but I have yet to come across a situation where this has in fact resulted in a short circuit and damage. What has been the experience of others in this regard?

28th Jul 2011, 7:52 am	#16
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Neat ways to mount replacement capacitors Connecting a GOOD electrolytic capacitor in parallel with an existing one cannot cause a short circuit. The short circuit would need to be there before the new capacitor was connected. My experience is that electrolytics fail to short circuit, low resistance and high leakage. Such a capacitor is likely to overheat and possibly explode if left in circuit. If you want to connect new caps in parallel with old you need to establish that the old caps have failed to open circuit or low capacitance and that the leakage is not too low. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

28th Jul 2011, 10:50 pm	#19
BakeliteBear Pentode Join Date: Feb 2008 Location: Leicestershire Posts: 204	Re: Neat ways to mount replacement capacitors Thanks Stitch1. Nice to know I am not alone!! __________________