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Date: Thu, 25 Mar 2010 16:53:28 +0000
Message-ID: <fc7eccec1003250953u78cbc56g8301e3651ad2aff8@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@googlemail.com>
To: rsgb_lf_group@blacksheep.org, uk500khz@googlegroups.com
DomainKey-Status: good (testing) 
Subject: LF: 500kHz and ADSL
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I've been doing some tests with the BT Internet ADSL connection and trying
to find out if there is any mutual interference.

The 500kHz beacon transmission  seems to make no difference whatsover to my
ADSL connection, it certainly doesn't affect the results of a speed test
whether it is on or off.  And I can detect no discernible different in noise
level whether the modem is off or on and operational.

So it looks as if my modification to the domestic phone wiring did what it
was supposed to.   I got into the wiring from the master socket and
installed a microfilter - the sort that is supposed to be used on EACH
extension -  between it and the rest of the house wiring, and connected only
the ADSL wire direct to the incoming pair.  This removed the original third
wire from the part of the circuit carrying the ADSL signal and reinstated
it, via the micro-filter on the low-pass-filtered audio path.   The BT
master socket no longer has its third ringer wire going anywhere.

Consequently, the ADSL signal is not being forced to travel all over the
house on and unbalanced three core cable asking for interference to be
injected / radiated.    I never liked the original concept, as supplied, of
sending the ADSL all over the house on and unbalanced cab;e, then having to
filter it out individually at each phone unit.   Its a nasty bodge, and just
a cop-out to save them from having to install a proper diplexer on teh
incoming line.

Mind you, its fortunate all my phones are the modern type that only need two
wires for ringer.   I'm not sure the tiny ringer capacitor in the
microfilter could do the job of ringing all the extensions I have connected.

The old BT Voyager modem does go away and retrain a lot more than it used to
since the service was "Supposed" to have been upgraded, so dropping the
connection for a minute or two several times a day, but the times it does
this are not related to the 500kHz beacon signal coming on line.

Andy
www.g4jnt.com

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<div>I&#39;ve been doing some tests with the BT Internet ADSL connection=
 and trying to find out if there is any mutual interference.=A0=A0=A0</div=
>
<div>=A0</div>
<div>The 500kHz beacon transmission =A0seems to make no difference whatsov=
er to my ADSL connection, it certainly doesn&#39;t affect the results of=
 a speed test whether it is on or off.=A0 And I can detect no discernible=
 different in noise level whether the modem is off or on and operational.<=
/div>

<div>=A0</div>
<div>So it looks as if=A0my=A0modification to the domestic phone wiring di=
d what it was supposed to.=A0=A0 I got into the wiring from the master soc=
ket and=A0 installed a microfilter - the sort that is supposed to be used=
 on EACH extension - =A0between it and the rest of the house wiring, and=
 connected only the ADSL wire direct to the incoming pair.=A0=A0This remov=
ed the original third wire from the part of the circuit carrying the ADSL=
 signal=A0and reinstated it, via the micro-filter on the low-pass-filtered=
 audio path.=A0=A0 The BT master socket no longer has its third ringer wir=
e going anywhere.</div>

<div>=A0</div>
<div>Consequently, the ADSL signal is not being forced to travel all over=
 the house on and unbalanced three core cable asking for interference to=
 be injected / radiated.=A0=A0=A0 I never liked the original concept, as=
 supplied, of sending the ADSL all over the house on and unbalanced cab;e,=
 then having to filter it out individually at each phone unit.=A0=A0 Its=
 a nasty bodge, and just a cop-out to save them from having to install a=
 proper diplexer on teh incoming line.</div>

<div>=A0</div>
<div>Mind you, its fortunate all my phones are the modern type that only=
 need two wires for ringer.=A0=A0 I&#39;m not sure the tiny ringer capacit=
or in the microfilter could do the job of ringing all the extensions I hav=
e connected.</div>

<div>=A0</div>
<div>The old BT Voyager modem does go away and retrain a lot more than it=
 used to since the service was &quot;Supposed&quot; to have been upgraded,=
=A0so dropping the connection for a minute or two several times a day, but=
 the times it does this are not related to the 500kHz beacon signal coming=
 on line.</div>

<div><br clear=3D"all">Andy<br><a href=3D"http://www.g4jnt.com">www.g4jnt.=
com</a><br></div>

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