Re: ADSL noise while on the phone

Roger Mills, in article <5c7pvnF2v2p2cU1@xxxxxxxxxxxxxxxxxx>,
says...

Do this with and without the modem connected. Also, if necessary, do it with
your handset plugged into the test socket (behind the master socket
faceplate) to eliminate any extension wiring you may have.

If you plug a handset directly into the test socket of a
master, then you will get both the voice and ADSL signal
entering the phone. Hence you may hear ADSL cross-modulation
products in the handset, generated by the telephone's circuit
that was never designed to work up to the 1.1Mhz of ADSL. If
you fit a (good) filter into the back socket and then plug a
phone into that, the filter should block the ADSL signal and
you shouldn't hear cross-modulation noise in the telephone.
The modem equivalent at the other end could drop out if it
doesn't hear your ADSL modem for a period so this test isn't
ideal.

You can plug an ADSL modem directly into the test socket,
using a suitable RJ11 to BT socket converter, to test the ADSL
part of the incoming service. The ADSL modem has inbuilt
wizardry to ignore the voice-band signals so doesn't need any
external filters. If this works:
2. Repeat the test via a faceplate filter (ADSLnation) with no
phone or wiring. If this also works, you have verified the
new faceplate filter's input side is OK. (It should be doing
nothing in the circuit at this time)
3. Repeat with a wired phone in the faceplate socket to check
the ideal, minimalist ADSL and phone installation.
4. Repeat with any house phone wiring connected to the back of
the faceplate.
5. Repeat with separate twisted-pair wires to the remote ADSL
modem from the A&B connections on the back of the faceplate.
6. Repeat with a wired phone and the ADSL modem in the office,
fed via the home wiring WITHOUT connecting the pin-3 ring wire
between the master and office slave sockets - use the A&B
connections on the back of the faceplate. Use another ADSL
filter in the office to filter off the phone signal, generate
a local ringing signal and provide an RJ11 socket for the
straight-through ADSL modem.
7. Finally, connect the DECT base station in the office to the
proven working, filtered phone socket. Leaving this till last
eliminates the cause of interference being from the base-
station and it's transmitter.

--
JohnW.
Replace the obvious with co.uk in 2 places to mail me.
.

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