Topband: RFI Down Under

Roger Kennedy roger at wessexproductions.co.uk
Tue Nov 24 12:46:36 EST 2020


As you say Phil, it's crazy that they omit the filtering components that
there is space for on the PCB, just to save a few pence. (they often do the
same in small chargers too - but not on the better ones)

Personally, I would have accepted the offer of a replacement PSU, as
filtering it on the Mains input is not the best way to do it if it's noisy
to start with.

When the PSU packed up in one of my 5 PCs I have here, I went to a local
shop who sold them for £10 (crazy price!) . . . but I asked to open it up to
make sure the filtering components were there  . . . they were, so I bought
it.

The biggest problem with Top Band Noise here in Britain is NOT noisy
switch-mode PSUs . . . it's the fact that 90% of the Internet Broadband is
delivered via overhead copper telephone wires. These radiate the hash for
miles, as I'm sure you can imagine.

I'm luckier than most, in that the phone wires in my street are underground
(being a new street). So I don't have an S9 +10dB noise level like most
locals. However, there are dozens of overhead phone cables at the end of my
street, just 300 feet away.

So apologies if I have trouble hearing weak signals calling me . . . I do
the best I can in an ordinary suburban location !

73 Roger G3YRO


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