Protocols that were proposed recently for adapting the error-control code from packet to packet in a frequency-hop packet radio network are evaluated for use on channels for which the fading distribution has fixed or slowly varying parameters. The protocols do not require channel measurements or pilot signals; instead, the receiver derives the necessary adaptation control information from its decoder during of the reception of each packet. The throughput achieved by each adaptive-coding protocol when it is used with a family of turbo product codes is compared with the capacity limit and with the throughput that is obtained from a hypothetical ideal protocol that is given perfect channel state information.