[BC] RF absorption by foliage

[Tom Bosscher]

 >Wonder if with IBOC the FCC is going to make DA's broadband
 >their arrays to keep all the IBOC trash to the same pattern as the
 >main channel? Be fun to measure that!!

 >Looey Munn

    Looey, that question has been asked a lot. By law, does an AM IBOC 
stations have to comply with the NRSC mask, at ALL azimuths? Since the 
Ibiquity system is based on slight of hand of a sideways, but legal 
reading of the rules, Ibiquity's AM IBOC should have to live by those 
rules.

    I've asked before, and it will be 3 weeks before I have time to do 
it myself, but has anyone measured NRSC compliance of a DA Ibiquity AM 
array, "around the horn"? Is the only place NRSC measurements are 
allowed is the TX common point? Funny, the FCC measures AM NRSC 
compliance away from the towers.

    I have personally talked to one am engineer who has made the 
measurements. He will not release the pictures of the AM station he 
checked on, as they are his client, but he did admit that this DA came 
no where close to being compliant at several points of azimuth.


    I am not anti Ibiquity AM IBOC. I am fully interested in the rules 
being applied fairly and uniformally.

    Any "Pro" DA AM IBOC stations that would like to step forward and 
offer their arrays to be analyzed and results published? Or maybe you 
have and you pass?

    My guess is that a simple and properly designed two tower DA should 
be OK. After that, I would not put my money on the investment risk.


       tom bosscher