LinoNYC said:
Of the 6 AM stations running iboc, only WCBS is unreliable using only the supplied 4" loop.
DX'ing is irrelevant to comm and non-comm broadcasters. if the system covers the COL, it works.
Of course I won't call you a liar. I will say that my experience is different than yours.
I am right on top of a 5kW low band blowtorch with a half million square mile footprint. The 4" loop is not capable of getting reliable HD lock. Neither is a Terk AM advantage. It takes a 2 foot loop to do it. There is nothing wrong with my tuner - it is a really good DX receiver getting stations hundreds of miles away daytime. Over a thousand at night. There is no noise source jamming it. But HD from the local? Unreliable.
DX'ing is the only way people in metro areas will hear HD. I can guarantee you - the stations in our metro area care about a LOT more than the COL. Sure, there are a million people there. But there are another 4.6 million in addition out in the suburbs. If you were a station owner, would you really want to only cover 20% of your potential listeners? I think not!
All I can do is report my experience. If you have better luck, so be it. It doesn't alter my observations in the slightest, because they are based on the scientific method. Be aware that fantastic claims like Houston FM HD in Huntsville in a car will be met with scepticism on the part of experienced listeners like myself. Extraordinary claims demand extraordinary evidence. Someone's word is not evidence of extraordinary reception, unless backed up with recordings at documentable locations.
I am an experienced DX'er, so there is a long list of things I will do right to begin with - like not laying the 4 inch loop flat, throwing a dipole in the corner all crumpled up, etc. Somehow, radio manufacturers have made receivers that actually work under those conditions with analog reception. But those same abuses by consumers will not net reliable HD reception. Educating consumers on how to DX is a fantastically futile endeavor - unless it was in the early 70's for blacked out football games on television. Somehow I don't think HD radio inspires the same fanaticism. Therefore, if another experienced engineer gets HD at home, and they are 50 miles out (as opposed to my 35 mile experience) with a dipole, they are probably located on higher terrain. So be it. If I were on the same terrain I might experience the same results. With an outdoor antenna, I've already pushed the limit to about 80 miles. Most of DX is the antenna anyway - so just about any HD receiver should do 80 miles, if they are located where I am with the same antenna. But how many consumers are going to erect a deep fringe FM antenna just to get HD radio? How many housaing associations allow antennas these days - there are deed restrictions against outdoor antennas most places.