id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc,mlocked 13257,Auto-tune of HD channels fails but works when transponders manually added,whpaul.thompson@…,,"Internet searches reveal that a failure to tune HD channels is not uncommon. Having identified the following workaround for PCTV 290e HD auto-tuning fail works for me (this is post Crystal Palace (UK) Mar 18 changes that also required a new wide-band aerial), sharing this may help others resolve their own difficulties and perhaps even help developers reduce the likelihood of HD channel scan failure. Symptoms: Post Crystal Palace changes need to retune my MythTV to locate changed HD channels. However, MythTV auto-tune fails to pick them up. Neither does TVheadend nor w_scan. w-scan does find the MUX/transponder but not the channels within. When I insert the 290e into my Windows laptop (running PCTV's TVCenter 6.4.9.1033) it finds the new HD channels automatically with a reported signal strength of > 80%. The issue is therefore not my aerial, too high or too low a signal but something software related on my arch linux arm box (4.4.47-1-ARCH armv5tel) common to the autoscan detection process in MythTV, TVheadend and w_scan. Workaround: Autodetect of the HD channels is no longer working (it did before the recent Crystal Palace changes). However, manually adding the MUXs/transports to MythTV/TVheadend etc '''and specifying that they are QAM256 modulation and 8Mhz bandwidth (rather than leaving them both at Auto)''' does enable both MythTV and TVheadend to discover the channels on the HD MUXes/transportes. I don't know why auto-detect does not work nor why specifying the modulation and bandwidth manually solves my problem, but am happy to offer my setup as a reproducible testbed for any expert willing to investigate the matter further.",Bug Report - General,closed,minor,31.0,MythTV - Channel Scanner,v29.0,medium,Fixed,,,0