  The problem of a constant modulus (CM) continuous wave (CW) waveform design
with the thumb-tack ambiguity function that meets the NTIA RSEC requirements is
addressed. The ad-hoc and alternating projection techniques are proposed to
modify the spectrum of a prototype waveform to meet the NTIA RSEC requirements,
retaining the "thumb-tack" property of the original waveform ambiguity
function. Periodic binary frequency shift keying (BFSK), Costas FSK, and
noise-like waveforms are modified to meet CM and NTIA RSEC requirements.
Introduced examples demonstrate the spectrum modification consequences and the
proposed technique's efficiency for generating the CM spectrum-controlled
waveforms with the thumb-tack ambiguity function.
