Where can I get one of these mains power filters

[Rob Flinn]

I'm looking for somewhere I can get one of these mains power filters.  It came out of my Telefunken M15a in the transport power supply.  I know i could probably get one from Hilperts in Berlin, but I'm trying to find somewhere in the UK to keep the shipping costs down

 

[abbey road d enfer]

I think you should consider replacing it with a modern version.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=1215449

 

[Rob Flinn]

I think you should consider replacing it with a modern version.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=1215449

If that's the way to go, I'll do it, certainly looks like a cost effective solution.  How does the new one get hooked up ?  I looked at the data sheet but it doesn't seem to give this info. The old one had 2 wires in & 2 wires out, whereas the device you recommend has 3 connections.

Do 1 & 2 (the outside conns) go across live & neutral, & the centre one to Earth ?? 

 

[Rob Flinn]

Or would this work ?  It seems that although this is more expensive it also has the inductors.

http://cpc.farnell.com/roxburgh/rx730-clip/filter-4a-chassis/dp/FT00832?Ntt=ft00832

The only difference in values that I can see is that the inductance value is 1mH on this one rather than 2mH on the original.

Excuse my ignorance with this, I've never had to deal with these before.

 

[Walrus]

Rob, from the picture, it looks like the original has a choke in the live and the neutral, just like the one from CPC, so I would go for that one.
The one Abbey links to just has X and Y capacitors and no chokes.

 

[Rob Flinn]

Thanks kev, does it matter that the chokes on the cpc one are 1/2 the value of the original ?

 

[abbey road d enfer]

The old one had 2 wires in & 2 wires out, whereas the device you recommend has 3 connections.

The old one has its chassis connected to the centre armature, so it it is earthed via the machine chassis.
I wouldn't care about the one with inductors. It was adequate at the time, useless today.

 

[Walrus]

Sorry Rob, can't help you with the maths of what half the inductance will do. Probably lower or raise the rejection turnover point.

Abbey, why is the one with inductors useless today??

 

[Rob Flinn]

I actually have gone PC today to get the parts through for another job, so it's done.  I hope it isn't useless ??  Abbey can you expand on your response please ?

 

[abbey road d enfer]

The noise spectrum of mains lines has changed a lot since the 60's. There used to be mainly machinery noise and appliance noise, which created relatively low freqency interferences; today the spectrum has shifted significantly and most of the equipment that generates high frequency components have built-in filters.

 

[Walrus]

OK I see.
So the one Rob's bought is not useless, just over engineered for todays mains.