Faulty Pickup in Philips AG2101? - UK Vintage Radio Repair and Restoration Discussion Forum

'LIVEWIRE?' · 29th Jun 2011, 11:41 am

Out of curiosity, after fitting a replacement stylus, I measured the resistance across the pickup tags, and it's virtually a short circuit (it's not the screened lead-I've replaced that!), and thought 'this can't be right!'

Presumably there should be a rubber or plastic 'sleeve' between the two contacts, into which
the stylus shank fits? This also set me thinking 'what kind of 'cartridge' is/was this - it's not crystal or ceramic, since there's no evidence of an element of any kind, and, as some members will know, the pickup leads are soldered directly to the tags(and were from new).

In use, the 'cartridge' is loaded with a parallel 470k resistor, which, to me, suggests a crystal or
ceramic type. The service manual, although very comprehensive, doesn't give any specifications for the cartridge, merely a (now long obsolete) part number.

Can anyone shed any light on this subject?

roffe · 29th Jun 2011, 7:14 pm

I've once seen a crystal used in this pickup and it's only a surprisingly small rectangular thin slice.
There are some interesting pictures of a AG2100 PU in this thread:
http://www.radiomuseum.org/forum/phi...20_mignon.html

'LIVEWIRE?' · 30th Jun 2011, 10:50 am

Thanks for the link, roffe. Those pictures are very informative. Pity my German isn't good
enough to understand the messages. Still I now know that anew stylus will be needed, unless I can find a short slice of suitable crystal(unlikely!!)

29th Jun 2011, 11:41 am	#1
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Faulty Pickup in Philips AG2101? Out of curiosity, after fitting a replacement stylus, I measured the resistance across the pickup tags, and it's virtually a short circuit (it's not the screened lead-I've replaced that!), and thought 'this can't be right!' Presumably there should be a rubber or plastic 'sleeve' between the two contacts, into which the stylus shank fits? This also set me thinking 'what kind of 'cartridge' is/was this - it's not crystal or ceramic, since there's no evidence of an element of any kind, and, as some members will know, the pickup leads are soldered directly to the tags(and were from new). In use, the 'cartridge' is loaded with a parallel 470k resistor, which, to me, suggests a crystal or ceramic type. The service manual, although very comprehensive, doesn't give any specifications for the cartridge, merely a (now long obsolete) part number. Can anyone shed any light on this subject?

29th Jun 2011, 7:14 pm	#2
roffe Hexode Join Date: Nov 2003 Location: Linkoping, Sweden Posts: 493	Re: Faulty Pickup in Philips AG2101? I've once seen a crystal used in this pickup and it's only a surprisingly small rectangular thin slice. There are some interesting pictures of a AG2100 PU in this thread: http://www.radiomuseum.org/forum/phi...20_mignon.html

30th Jun 2011, 10:50 am	#3
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Faulty Pickup in Philips AG2101? Thanks for the link, roffe. Those pictures are very informative. Pity my German isn't good enough to understand the messages. Still I now know that anew stylus will be needed, unless I can find a short slice of suitable crystal(unlikely!!)