This year’s US incentive auction of 600 MHz broadcast spectrum is unlikely to be the goldmine that analysts were expecting only a few months ago, and will almost certainly deliver far less revenue than 2014’s surprise hit, the AWS-3 sale. According to new estimates made by JP Morgan, the 600 MHz auction, which kicks off on March 29, is likely to fetch between $25bn and $35bn – not the $60bn or even more which Barclays, Kagan Media and Moody’s were forecasting last autumn. JP Morgan’s figure would equate to $1 to $2 per MHz/POP, a big comedown from $2.68 per MHz/POP for AWS-3, which ended up with $45bn in bids. This is partly because, despite much speculation last year that…