Requirements for new phones.

Have the BABT requirements for new phones changed at all to reflect
ADSL?
Things like not injecting RF down the line, ...

On 01 Jul 2005 20:48:02 GMT,it is alleged that Ian Stirling
<(E-Mail Removed)> spake thusly in uk.telecom.broadband:

>Have the BABT requirements for new phones changed at all to reflect
>ADSL?
>Things like not injecting RF down the line, ...

Not sure on that, but it shouldn't matter even if they do, any decent
filter should take care of any out-of-band signals generated by the
phone, the filtering section is mainly designed to filter signals *to*
the phone, but it should be symmetrical enough to prevent major
problems.

--
There is not the slightest indication that nuclear energy will
ever be obtainable. It would mean that the atom would have to
be shattered at will.
- Albert Einstein, 1932

On 01 Jul 2005 20:48 GMT, Ian Stirling <(E-Mail Removed)> wrote:

>Things like not injecting RF down the line, ...

Does the filter between the phone and the line not work in both directions!

--

UK ADSL <http://tinyurl.com/5jpa4> - Happy to save cash with Plus.Net!!

poster <us-(E-Mail Removed)> wrote:
> On 01 Jul 2005 20:48 GMT, Ian Stirling <(E-Mail Removed)> wrote:
>
>>Things like not injecting RF down the line, ...
>
> Does the filter between the phone and the line not work in both directions!

My old one diddn't.
I decided not to bother fiddling with home-brew filters, and have obtained
one from solwise.

However, the old ones main virtue was that it was 6% of the price of the
solwise one, so I shouldn't probably have expected very much.

"Ian Stirling" <(E-Mail Removed)> wrote in message
news:42c6814e$0$41918$(E-Mail Removed)...
> poster <us-(E-Mail Removed)> wrote:
>> On 01 Jul 2005 20:48 GMT, Ian Stirling <(E-Mail Removed)> wrote:
>>
>>>Things like not injecting RF down the line, ...
>>
>> Does the filter between the phone and the line not work in both
>> directions!

Will new phones (and phone-like equipment such as dial-up modems and fax
machines) be required to have built-in ADSL filter circuitry to prevent
separate microfilters being needed?

Martin Underwood <(E-Mail Removed)> wrote:
> "Ian Stirling" <(E-Mail Removed)> wrote in message
> news:42c6814e$0$41918$(E-Mail Removed)...
>> poster <us-(E-Mail Removed)> wrote:
>>> On 01 Jul 2005 20:48 GMT, Ian Stirling <(E-Mail Removed)> wrote:
>>>
>>>>Things like not injecting RF down the line, ...
>>>
>>> Does the filter between the phone and the line not work in both
>>> directions!
>
> Will new phones (and phone-like equipment such as dial-up modems and fax
> machines) be required to have built-in ADSL filter circuitry to prevent
> separate microfilters being needed?

You don't actually really require microfilters, in general, if you design
it in from the beginning as a requirement.
You have to pay attention to things like not having RF suppression on
the line side of your phone, but keep that on the other
side of the interface, ...