Just thought I'd toss this out there.
I recently went to take a field strength reading at my 7100 foot test spot (a parking lot off the side of the highway).
I had also brought along some radios to test actual reception.
I can report my station was loud and clear on a GE Super Radio (same as the Radio Shack or RCA Super Radio), also loud and clear on the radio in my SUV, a 2010 Ford Escape. As well as loud and clear on a Grundig S350DL radio (a pretty decent communications receiver) and also clear as day on a really cheap 1970's vintage Panasonic little transistor radio (you know, the ones with the 9V battery that you used to listen to the baseball game or Steppenwolf songs on top 40 radio back when you were a teenager). But then I fired up the little Tecsun PL-310 specifically because I was asked to get a dBu reading at this spot, and it picked up so much static and noise that my station was unlistenable!
Demonstrating the HUGE differences in "range testing" with different radios. Also makes me wonder what is so different about the Tecsun that I would have easily considered myself out of range if I were relying on it exclusively!
TIB
the good ol classics were of good design and quality components. the tecsun is cheapo china sweatshop junk.
do you have elevated wiring in your community or is all the power lines under ground?
your results are a pretty good indicator (if the lines are elevated) that you are getting some carrier current action in combination with possibly good ground conductivity and a low local RF noise floor.
in short you are very lucky and have stumbled across a happy accident that is likely not uniformly replicable anywhere else even locally.
I fired up the little Tecsun PL-310 specifically because I was asked to get a dBu reading at this spot, and it picked up so much static and noise that my station was unlistenable!
Just to observe that my Tecsun PL-310 is able to receive WHO, 1040 kHz, Des Moines, IA daytime groundwave just beyond their 100 µV/m field contour (MP3 clip below).
Its too noisy to listen to for more than a short time, but not totally unlistenable.
Tim's post is interesting and brings to mind that when we talk about range we are actually talking about the range of a system. This system includes the transmitter, tx antenna, signal path, receiving antenna, and the receiver.
In engineering, many designs are made to address the "worst case" but we, on Part15 AM, don't have the ability to do so without restrictions at the transmitter. In my mind, the single biggest impediments to AM range are the poor quality receivers, high ambient noise produced by modern electronics, and lack of suitable receive antennas.
The first thing a ham operator does, if able, is to erect an outdoor antenna which also functions to receive. In the "good ole days" of early radio, manufacturers would recommend use of an outdoor aerial since, for many, radio stations were distant. Before cable TV, TV antennas sprouted from rooftops across America. Most people today don't even think of antennas or don't want to be bothered since local AM stations can be received without super antennas.
Allow me to repost that I received a listenable Talking House signal from 2.3 crow flies miles away using a Yaesu FRG-100 (a pretty hot receiver) and an outdoor antenna. Imagine if all AM listeners had good receivers and antennas what kind of coverage our micro-stations could achieve.
Neil
Shows you that things aren't the way they used to be.
Even a cheapy pocket radio from the 70s was better than what you get now.
Mark
Timinbovey you brought a very hot new subject that we need to focus on. If we talk about range we need to maybe test with more than one Radio (if we can). Show video's with that Radio receiving the station. Maybe we should have links on our station's web sites to where a listener can buy a good Radio to receive our stations. One thing no one talks about is those magnetic loop antennas that you can buy or build that has a capacitor that you can sit beside the Radio and it improves AM Range. There are plenty of examples on youtube. But a listener will want to be able to buy one and set it next to their Radio to pick up your station. So though Station8 is hard at work with his antenna, we need to educate our listeners as to how they can get the most range from our micro broadcasting stations on AM. Thanks Tim for reminding us of this. Just as the transmitter is important, the receiver and its performance is ever so important in the system. Lets talk about brand, and model here too. Now this is a part 15 project that we can work on without bickering.
I've had on my station website a page called "Tuning Tips" that also includes info on the Super Radio (in it's many variations). See:
http://ironrangecountry.com/tuningtips.html
I've even gone as far as keeping a few Super Radios on hand, new in the box, to sell to people who inquire. I've actually sold three and have two more on hand. Even the later "less good" (according to internet lore) models are far superior to the typical radio you buy at the department store.
And yes, I consider my range to be this good (during the day) mostly because of the very low noise floor here. Tuning the AM band here between stations is nearly silent. But soon as the sun goes down the noise and distant stations come rolling in!
TIB
That's a nice, straight forward 'tuning in' page TIB, not like commercial radio web sites that look similar to one another, maybe because they're in the same radio group. It reminds me of pages done on FrontPage, as I had practiced on, where you make the page from scratch and add text and pictures one at a time.
Some neighbors know about my station, but I don't know if they tune it in. I have that kind of radio pictured on your page! It's really old though, probably one of the early ones, and the tuning pot is dirty, so at the high end of the dial it's really hard to lock in on stations.