I have seen press releases indicating that KNOM is apparently preparing to convert to digital audio. If this means AM IBOC, they are probably going to be disappointed. AM HD radio in the lower 48 seems to be DOA. Many stations are dropping it. There are no listeners and (except for some vehicles) no receivers.
That is incorrect. KNOM has NO plans for digital (IBOC). What IS planned is the modification of the Nautel ND25 to DCC which means "Dynamic Carrier Control". It's in no way digital. DCC is a modulation method very popular in Europe and rapidly coming into use here. It reduces the carrier during periods of relative low modulation. Those who use it testify to power savings (electrical power) of up to 37%. I expect somewhat less when we do the modification next week because KNOM uses a limiter made years ago by CRL and later made, for a short time, under the name "Amigo". It's pretty nasty limiting, as adjusted for extremely narrow bandwidth. Not something I'd recommend for most stations. The point at KNOM is "reach". Pushing the signal as far out as possible since the intent is not to serve Nome with the AM (there's an FM for that) but to reach tiny villages which otherwise would have no service. Given the choice between high quality audio with no signal in your village versus no signal at all then the choice has proven obvious.
But in case KNOM were ever tempted toward digital it wouldn't happen. First, because as you have correctly stated, no audience. Second, because the folded unipole antenna (6 folds on a 230-foot tower, short because of the airport) would not allow IBOC.
I likely won't be logging in here from Nome but will be back to "civilization" in about a week so if anybody is interested in how this all turns out, make note below and I'll do my best to fill you in.
About that limiter: These are very prone to power supply failures. Potted power supplies that can't be field repaired. When CRL issued a "last call" for them about 8-9 years ago I bought several and have them stashed right on top of the limiter chassis so the next person doing the engineering can't miss finding them when needed. Also there is a second (Amigo) limiter of the same type in the same rack. BOTH limiters are fed audio and the output of both limiters feeds the transmitter. There is, however, a relay arrangement which permits only one of them to be powered at any given time; remoted to the studio. That's because the doggone things never fail unless there's a blizzard and 50+ MPH winds at the transmitter site, 3-miles out of town on a seldom-plowed gravel road. Yes, snowmobiles are helpful but not fun in the conditions described. Been there; done that. Forgot to buy the tee-shirt off the polar bear camped out under the generator building. Had other things on my mind at the time. Like getting the H- out of there!
