[BC] Harmonic measurements

[Edwin Bukont]

Phil Alexander, if I may offer a clarification on your comment. 
 
While the measurment standard for analog FM stops after a few harmonic intervals, stations running HD should do measurments out to the 10th harmonic. 
 
We have seen a fair number of instances with interference at the 9th harmonic, sometimes caused, rather than mitigated, by real time adaptive correction.  The key is to be sure you are obtaining a valid sample to a measuring device with suitable displayed dynamic range and low enough noise floor.
 
The test and measurment guidance from most manufactuers of HD transmission systems, and the policy of some broadcast groups, is to check out to the 10th harmonic. 
 
 Some guidance on this is provided in NRSC documents on methods of measuring RF Mask compliance.

Edwin Bukont CSRE, DRB, CBNT 
V- 240.417.2475; F- 240.368.1265