Reducing RFI off the powerline into radio set

[wa2ise]

Originally Posted by Electronic M

Many newer TV's/monitors (80's and newer) have this or a similar network...It's easier to just cut off the section of a junk set's PCB that contains this network add some power connectors and throw it in a box than make one from scratch....

That's essentially what I did, though I tucked mine inside the radio cabinet behind the speaker.

These pictures don't show this addition, but if you look closely enough, there is room for a board behind the speaker. I also moved the power cord cheater cord socket away from the AM ferrite rod antenna. There's a masonite back cover you don't see here as well.

Better pictures:
Caps in the filter are X2's.



This mod almost makes it seem like the early 70's on the AM band, before switching power supplies existed.

[dieseljeep]

Is the large WW resistor, a voltage drop for the radio? If so, what value is it.
My older GE Superadio picks up a lot of interference from the neighbors, even when I'm using it on batteries, but much worse on AC.
It seems like The building next to me has some kind of a motion detector alarm system, that emits an RF pulse. I don't think, I can clean that up.

[dieseljeep]

Originally Posted by dieseljeep

My older GE Superadio picks up a lot of interference from the neighbors, even when I'm using it on batteries, but much worse on AC.
It seems like The building next to me has some kind of a motion detector alarm system, that emits an RF pulse. I don't think, I can clean that up.

Regarding the interference from the neighbor building, I ran an antenna to the outside of the building and the noise got a lot worse.

[Electronic M]

Originally Posted by dieseljeep

Regarding the interference from the neighbor building, I ran an antenna to the outside of the building and the noise got a lot worse.

I wonder if a grounded shield on the side of the antenna the interference is coming from would help.

[jr_tech]

Originally Posted by dieseljeep

Regarding the interference from the neighbor building, I ran an antenna to the outside of the building and the noise got a lot worse.

Did you connect to a decent ground as well? Otherwise, results might be inclusive.

A better test is to take a good portable outside, and observe the interference level.

jr

[wa2ise]

Installed a similar filter in another radio, and it works as well as my first radio. This is a Hitachi AM-FM K760H. Added an extra coil to this filter board for more filtering.

[dieseljeep]

Originally Posted by jr_tech

Did you connect to a decent ground as well? Otherwise, results might be inclusive.

A better test is to take a good portable outside, and observe the interference level.

jr

I did take my GE Superadio outside and the noise seems to be coming from the building behind me.
This poor reception is in my workshop building. My AM reception at my residence is good in most rooms of the house.