addchan
error = addchan(chans, maxchans, nchans, ieee, freq, maxregpower,
error = addchan(chans, maxchans, nchans, cent->ic_ieee, cent->ic_freq,
error = addchan(chans, maxchans, nchans, extc->ic_ieee, extc->ic_freq,
error = addchan(chans, maxchans, nchans,