Are some AM receivers more sensitive to household background noise than others?

[gar hi]

Or does it just depend on the size and strength of the internal antenna?

I'm just wondering because it's gotten worse in my place since I've been here.

There's a cacophony of static and buzzing on my PR-D5 anymore indoors but not much on my Sony Walkman which made me assume it just had to do with antenna size and strength.

 

[Schroedingers Cat]

I wonder if any of O.G. Villard's antenna designs would have an impact on AM BC reception in noisy environments. I know they were designed for SW broadcasts that were being jammed. I think it has something to do with polarization of the desired signal and interfering signals, but it was coherent RF for both signals. Also the electrical and magnetic properties are involved, like a direction finder antenna array, consisting of a ferrite loop and a whip.

 

[davideduardo]

Or does it just depend on the size and strength of the internal antenna?

I'm just wondering because it's gotten worse in my place since I've been here.

There's a cacophony of static and buzzing on my PR-D5 anymore indoors but not much on my Sony Walkman which made me assume it just had to do with antenna size and strength.

Noise and AM signals are all picked up by the same antenna. So if it seems noisier than before, it is because localized noise has increased.

Atmospheric noise (what is truly called "static") varies by location and season. Unfortunately, static has come to mean today any kind of noise that is heard in a broadcast, including man made interference.

 

[gar hi]

I know the noise has increased but I was wondering if there are any other parts of receivers other than the antenna that are a factor in how much of that unwanted background noise it will pick up.

 

[PTBoardOp94]

Yes, there are factors other than the antenna. For example,

- the radio's own power supplies can provide noise
- the radio could be poorly shielded and pick up ambient noise from household electronics.
- the tuner circuit could induce noise

In reality, just about everything you do to a signal creates noise, distortion, or both. Just passing a signal through a resistor creates via different phenomena, but the primary one is the Johnson noise.

 

[Schroedingers Cat]

There are some AM radios with digital tuning that produce so much interference that you can barely tune the strongest signals. I have one that was at a Pottery Barn clearance outlet store that my spouse thought looked nice and it was like that. I think you would have to put turns of wire on the ferrite rod and run it to a loop or otherwise outside the radio to work.

 

[boombox4]

Yes, some radios are less impervious to certain noises than others. The ANL is different. On some of my older radios, various pops (the thermostat on the stove when cooking) can be ear popping, on others it's muffled.

The PR-D5 has a noise reduction circuit somewhere but I think it's pop noise suppression, not necessarily the kind which would eliminate noise from switching power supplies and the like -- I'm not sure you can really eliminate that noise from being picked up by a radio. Most of them are designed to reduce impulse noise.

I don't think the PR-D5 itself produces any internal noise. Internally it's noise free -- at least mine is. My HDR-16 (HD radio in the same case) is a different matter -- the LCD is noisy on the AM band, unfortunately.