Mike Knudsen wrote:
In article , --exray-- writes:

Was that mechanical buzzing of the transformer, or was there some
electrical problem? My radio buzzes through the speaker.

No, this was electrical buzzing just like receiving power line noise.
mechanically it was quiet.

Any idea of what was wrong with the power trans inside, or did you just replace
it and throw it away? Maybe the shielding between the windings was kaput.

Insulation breakdown.

I have a cheap AM/FM clock radio that sounds like light-dimmer power line noise
even on FM. I've tried tacking caps all over the place, to no effect. The DC
supply is clean on a scope. You have to wonder how such a sound gets into FM
-- it sounds exactly like the sort of noise that sends you reching for the ANL
switch on a real radio. --Mike K.

It has a vacuum fluorescent display, doesn't it? Disconnect the display
and it'll be quiet.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In article , (Scott Dorsey)
writes:

Any idea of what was wrong with the power trans inside, or did you just
replace
it and throw it away? Maybe the shielding between the windings was kaput.

Insulation breakdown.


OK, so it was arcing internally, and getting ready to let smoke out, in great
puffs :-)

I have a cheap AM/FM clock radio that sounds like light-dimmer power line
noise
even on FM.

It has a vacuum fluorescent display, doesn't it? Disconnect the display
and it'll be quiet.

Kinda spoils the fun of a clock radio, especially when the radio sux but the
clock is very reliable (keeps perfect time during power outages).
Seriously, this is a big red LED display. The vacuum flourescent jobs are
actually electron tubes, were used back in late '70s on clocks and Gottlieb
pinball machines.

Most good SW portable radios do have s wticht to kill the digital readout,
though -- good idea. --Mike K.


Oscar loves trash, but hates Spam! Delete him to reply to me.

In article , (Scott Dorsey)
writes:

Any idea of what was wrong with the power trans inside, or did you just
replace
it and throw it away? Maybe the shielding between the windings was kaput.

Insulation breakdown.


OK, so it was arcing internally, and getting ready to let smoke out, in great
puffs :-)

I have a cheap AM/FM clock radio that sounds like light-dimmer power line
noise
even on FM.

It has a vacuum fluorescent display, doesn't it? Disconnect the display
and it'll be quiet.

Kinda spoils the fun of a clock radio, especially when the radio sux but the
clock is very reliable (keeps perfect time during power outages).
Seriously, this is a big red LED display. The vacuum flourescent jobs are
actually electron tubes, were used back in late '70s on clocks and Gottlieb
pinball machines.

Most good SW portable radios do have s wticht to kill the digital readout,
though -- good idea. --Mike K.


Oscar loves trash, but hates Spam! Delete him to reply to me.