Importance of power supply....

Just got back from customer. Their previously working ADSL setup stopped
working a couple of weeks ago. The router was reporting reasonable (not
exceptional) SNR/attenuation figures,, but it could not attain reliable
sync.

Today, we swapped everything - router, filter, cables, etc - and it worked
fine. We then reverted step by step back to the old hardware to find out
what was wrong, and it still worked.

Only when I went to rebox the replacement router did I realise we'd
accidentally left the old router using the new PSU. Switching back to the
old PSU broke the connection consistently. We'd found our fault.

The odd thing is that the working PSU was only 7.5v (1.5A), where the
original PSU was 12v (1A). (I don't know what sort of internal voltage these
things run at? I guess a lot of the 12V is dropped across a voltage
regulator internally?)

The other odd things is that replacing the cheap (eBuyer) filter with a
decent (Excelsus Z-420UKP2J) one actually gave slightly worse SNR figures,
although with the correct PSU both filters worked fine.

In all the advice I've heard here recently nobody that I noticed mentioned
the PSU, so I thought it worth mentioning.

[I now have a new router without a PSU - where's a good source of cheap but
reliable 12V PSUs?]

--
Mark Rogers,
More Solutions Ltd

On Thu, 8 Sep 2005 11:01:06 +0100, "Mark Rogers"
<mark-(E-Mail Removed)> wrote:

>In all the advice I've heard here recently nobody that I noticed mentioned
>the PSU, so I thought it worth mentioning.

(E-Mail Removed)

Phil
--
Tiscali - dialup speeds at Broadband prices, see
http://bbs.adslguide.org.uk/postlist...&Board=tiscali

AOL - the unlimited ISP of choice for heavy downloaders.

"Mark Rogers" <mark-(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> Just got back from customer. Their previously working ADSL setup
> stopped working a couple of weeks ago. The router was reporting
> reasonable (not exceptional) SNR/attenuation figures,, but it
> could not attain reliable sync.
>
> Today, we swapped everything - router, filter, cables, etc - and
> it worked fine. We then reverted step by step back to the old
> hardware to find out what was wrong, and it still worked.
>
> Only when I went to rebox the replacement router did I realise
> we'd accidentally left the old router using the new PSU.
> Switching back to the old PSU broke the connection consistently.
> We'd found our fault.
>
> The odd thing is that the working PSU was only 7.5v (1.5A),
> where the original PSU was 12v (1A). (I don't know what sort of
> internal voltage these things run at? I guess a lot of the 12V
> is dropped across a voltage regulator internally?)
>
> The other odd things is that replacing the cheap (eBuyer) filter
> with a decent (Excelsus Z-420UKP2J) one actually gave slightly
> worse SNR figures, although with the correct PSU both filters
> worked fine.
>
> In all the advice I've heard here recently nobody that I noticed
> mentioned the PSU, so I thought it worth mentioning.
>
> [I now have a new router without a PSU - where's a good source
> of cheap but reliable 12V PSUs?]
>
Similar circs at one of my customers - power surge blew the PSU of
a Belkin router. I replaced it with one from here:

http://www.active-robots.com/product...ersupply.shtml

Scroll down and you'll find a neat 12v 1.33A switching regulator. I
had to splice the DC power plug from the old supply onto the lead
of the new PSU, but it works well.

In an earlier contribution to this discussion,
Phil Thompson <(E-Mail Removed)> wrote:

> On Thu, 8 Sep 2005 11:01:06 +0100, "Mark Rogers"
> <mark-(E-Mail Removed)> wrote:
>
>> In all the advice I've heard here recently nobody that I noticed
>> mentioned the PSU, so I thought it worth mentioning.
>
> (E-Mail Removed)
>
I'm afraid that OE (yes, I know!) insists on thinking that that is an email
address rather than a URL. Could you possibly present the reference in a
universally acceptable way?
--
Cheers,
Tim
______
Please reply to newsgroup. Reply address is invalid.

"Mark Rogers" <mark-(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> The odd thing is that the working PSU was only 7.5v (1.5A),
> where the original PSU was 12v (1A). (I don't know what sort of
> internal voltage these things run at? I guess a lot of the 12V
> is dropped across a voltage regulator internally?)
>
Could it be the original was 12v unregulated, the newer one
regulated? That would reduce power consumption, hence temperature
in the router.

> The other odd things is that replacing the cheap (eBuyer) filter
> with a decent (Excelsus Z-420UKP2J) one actually gave slightly
> worse SNR figures, although with the correct PSU both filters
> worked fine.
>
Many people disparaged the eBuyer cheapos, presumably equating cost
with quality. I've never had a problem with them.

On Thu, 8 Sep 2005 12:16:16 +0100, "Tiscali Tim" <(E-Mail Removed)>
wrote:

>> (E-Mail Removed)
>>
>I'm afraid that OE (yes, I know!) insists on thinking that that is an email
>address rather than a URL. Could you possibly present the reference in a
>universally acceptable way?

It isn't a URL, it is a message ID.

--

Tiscali Tim wrote:
> In an earlier contribution to this discussion,
> Phil Thompson <(E-Mail Removed)> wrote:
> >
> > (E-Mail Removed)
>
> I'm afraid that OE (yes, I know!) insists on thinking that that is an
> email address rather than a URL. Could you possibly present the
> reference in a universally acceptable way?

Not really what you're asking but:

http://makeashorterlink.com/?A38E121CB

Thanks, Phil - shame I missed it. Must look harder!

--
Mark Rogers,
More Solutions Ltd

In an earlier contribution to this discussion,
Mark Rogers <mark-(E-Mail Removed)> wrote:

> Just got back from customer. Their previously working ADSL setup
> stopped working a couple of weeks ago. The router was reporting
> reasonable (not exceptional) SNR/attenuation figures,, but it could
> not attain reliable sync.
>
> Today, we swapped everything - router, filter, cables, etc - and it
> worked fine. We then reverted step by step back to the old hardware
> to find out what was wrong, and it still worked.
>
> Only when I went to rebox the replacement router did I realise we'd
> accidentally left the old router using the new PSU. Switching back to
> the old PSU broke the connection consistently. We'd found our fault.
>
> The odd thing is that the working PSU was only 7.5v (1.5A), where the
> original PSU was 12v (1A). (I don't know what sort of internal
> voltage these things run at? I guess a lot of the 12V is dropped
> across a voltage regulator internally?)
>
> The other odd things is that replacing the cheap (eBuyer) filter with
> a decent (Excelsus Z-420UKP2J) one actually gave slightly worse SNR
> figures, although with the correct PSU both filters worked fine.
>
> In all the advice I've heard here recently nobody that I noticed
> mentioned the PSU, so I thought it worth mentioning.
>
> [I now have a new router without a PSU - where's a good source of
> cheap but reliable 12V PSUs?]

This has actually been discussed in uk.d-i-y of all places! - (where I post
using a different 'handle') http://tinyurl.com/8ud2h

My 3Com wireless router gave up when my line was upgraded - and would not
synch after it been on for about 30 minutes. I got it (but not it's power
supply!)replaced by 3Com under warranty - but the new one was just the same!
I have another router and a PCI modem - both of which work on the line - so
I knew it wasn't the line. Ultimately, I tried the 3Com router with a
'foreign' power supply which I had lying around - and it works perfectly,
with a much higher noise margin than it ever reported when using 3Com's
supply. I assume that the 3Com switch mode power supply generates a lot of
electrical noise which the router's modem confuses with noise on the ADSL
line.

I could do with replacing my 'foreign' power supply because, although it is
rated at 1000mA - which should be ok - it's getting a bit hot, suggesting
that it's running close to (or above!) its limit. Based on other people's
experience of 3Com's after-sales service, there doesn't seem to be much
point in getting them to replace it. I'm wondering about one of the
universal supplies from CPC, for about a tenner.
http://cpc.farnell.com/jsp/endecaSea...=PW00140&N=411

--
Cheers,
Tim
______
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In an earlier contribution to this discussion,
Mark Rogers <mark-(E-Mail Removed)> wrote:

>
> Not really what you're asking but:
>
> http://makeashorterlink.com/?A38E121CB
>
Thanks, that did it! [It's actually referencing something which *I* wrote!]
--
Cheers,
Tim
______
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In an earlier contribution to this discussion,
Tony <(E-Mail Removed)> wrote:

> On Thu, 8 Sep 2005 12:16:16 +0100, "Tiscali Tim" <(E-Mail Removed)>
> wrote:
>
>>> (E-Mail Removed)
>>>
>> I'm afraid that OE (yes, I know!) insists on thinking that that is
>> an email address rather than a URL. Could you possibly present the
>> reference in a universally acceptable way?
>
> It isn't a URL, it is a message ID.

OK, so how do I get to the message from this link? [If I click on it, OE
insists on trying to send an email to it. If I paste it into my browser,
*that* doesn't understand it either!]
--
Cheers,
Tim
______
Please reply to newsgroup. Reply address is invalid.