UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Two DSL filters, two 706 phones, bell tinkle

Tim · 22nd Jul 2019, 7:15 pm

The combination of filters and 706/746 phones may have increased your "ren", because, as already stated ADSL filters have the bell ringing components in.

Actually they shouldn't really be called ADSL filters, because the ADSL isn't filtered at all. It's connected straight across the line, and it's actually the phone that's filtered.
There are two coils inside, in series with each leg of the line that allow the DC and low frequency AC(audio and ringing) through but block higher frequencies. So when the handset is lifted, the ADSL cant "see" the loop through the filter coils. The ringing components are in parallel, so you should be able to remove them( in theory) without affecting anything.

BTW, both types of filtered master socket have a facility for running an ADSL(only) extension, so you could of had the hub wherever you wanted.

22nd Jul 2019, 7:15 pm	#17
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,308	Re: Two DSL filters, two 706 phones, bell tinkle The combination of filters and 706/746 phones may have increased your "ren", because, as already stated ADSL filters have the bell ringing components in. Actually they shouldn't really be called ADSL filters, because the ADSL isn't filtered at all. It's connected straight across the line, and it's actually the phone that's filtered. There are two coils inside, in series with each leg of the line that allow the DC and low frequency AC(audio and ringing) through but block higher frequencies. So when the handset is lifted, the ADSL cant "see" the loop through the filter coils. The ringing components are in parallel, so you should be able to remove them( in theory) without affecting anything. BTW, both types of filtered master socket have a facility for running an ADSL(only) extension, so you could of had the hub wherever you wanted. __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."