Last week the FCC issued its list of experimental licenses granted from Jan. 1 to Feb. 1, 2014 and while there was only one that fell within broadcast spectrum, there were a few others that will likely be of interest to ham radio operators using the shared 420-450 MHz band.
Boeing received experimental license WG2XZQ to operate in the 54-72 MHz (TV Channels 2-4), 76-87 MHz (TV channels 5 & 6) and 173.28-173.40 MHz bands for radio testing. According to Boeing's application, the testing will use military ARC-210 and URC-200 radios and consist of a simple "Check One, Check Two" radio test between two attached radios at any two frequencies in these bands. Testing will take place "on the flight line" in St. Louis, Mo. In its application Boeing said this license would replace STA WG9XIE.
Ham radio operators in the area north of Denver may notice transmissions from Detect, Inc. on 449 MHz in connection with the testing of wind profiler radar and remote sensing technology mobile around Longmont, Colo.
General Dynamics is using the same band for development of software-defined radios operating with Wide Networking Waveform mobile technology in Scottsdale, Ariz. The specific frequency bands are 420-424.75 MHz, 445.75-450 MHz (adjacent to the 450 MHz broadcast RPU band), 1370-1400 MHz and 1755-1850 MHz. For a good description of what the Wide Networking Waveform involves see Kevin Maier's article Mapping waveforms to systems: What would a wideband networking waveform system require? and Spectrum Signal Processing by Vecima's paper Wideband Networking Waveform OFDM PHY Physical Layer Implementation of WNW on the SDR-4000 Platform. This is a very interesting technology that I can see expanding beyond military applications before too long.
The complete list of experimental license grants from Jan 1 to Feb. 1, 2014 is available in the FCC Public Notice Report No. 453 – Experimental Actions.