When is enough enough?

[ai4i]

What is an ideal signal strength for stations on the standard broadcast band?
25mV/M, 1v/M, enough to shake tooth fillings?
Does it matter where on the band it is?

[Deep Thought]

In an urban environment 5 mv/m is usually enough to get past most of the electrical interference. Out in the sticks you can still have decent received audio with 1/20th that.

God in your toaster requires around 2000 mv/m.

Where it is on the band affects how far the signal 'carries' due to the increased attenuation with frequency. The required signal numbers, however, remain fairly constant.

[ai4i]

I would not say that 5mv/m is a "punchy" signal as the old 25mv/m requirement was.
My experience is that for two stations with the same field strength, however it is derived (distance, power, DA) the station higher up on the dial will be more receicable in areas such as within and between large buildings.

[Deep Thought]

Punchy?

What are you using for a reference? Do you have a field intensity meter to determine what field you are in at the time you are listening? Many stations put far more than 5 mv/m over their community of license...some much more, and relying on a theoretical signal map for your comparison is folly.

The frequency does affect how the signal gets into enclosed areas. That is not what you asked though.

[PaulBWalkerJr]

In an urban environment 5 mv/m is usually enough to get past most of the electrical interference. Out in the sticks you can still have decent received audio with 1/20th that.

God in your toaster requires around 2000 mv/m.

Where it is on the band affects how far the signal 'carries' due to the increased attenuation with frequency. The required signal numbers, however, remain fairly constant.

I've lived in areas where 0.5 mv/m is definately listenable. The 0.5 mv/m of KNLV-AM and KEYZ-AM comes to mind as I've listened to both stations personally in their respective 0.5 mv/m contour.

[Deep Thought]

It's mostly a matter of the noise floor. I've driven through the hinterlands listening to signals I know are well below 500 uV/m. Class-A's are protected from co-channel interference to 100 uV/m daytime. In an urban environment you aren't going to get clear reception at that level though, and the FCC has recognized that for decades...we don't count population in towns with more than 2500 people unless they receive 2 mV/m or better, for example.

It all comes down to programming though. You can have 50 KW and 100 mV/m and no listeners while the 250 watter in the next county has people stringing up antennas to pick them up. Folks will put up with a lot to get programming they want and can't find locally. If that wasn't true Internet radio would be a total bust.

[R. Fry]

Except in the summer I can pick up a daytime signal from the Chicago clears, and WHO, Des Moines here on the south side of Quincy, IL (pop 40,400), using an indoor radio. All of those stations put much less than 500 uV/m groundwave into Quincy.

They are noticeably noisy, for sure, but they're listenable.

Rich

[NECRAT]

I can barely hear locals on AM much less any decent skywave, unless I am in the bedroom top floor. The broadband noise across the entire AM band here is enough to drive you to drink. Except for the strongest locals, and even them on cheaper radios, you cant listen to.

I think the neighbor has a dimmer or a curly q bulb.